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TRX 33 Owners Manual

1. E j 2 4 I 27 0 OWNERS MANUAL UR mi E od zt L9 p E mw E LI ou 4 kom LS O m Pe M x I 3 SaaS 777 7 y al m d I B a TOES TEAS oN YE 2727770 7 24 WH EREDE OWE alienate Traxxas 1100 Klein Road Plano Texas 75074 Phone 972 265 8000 Toll free 1 888 TRAXXAS Traxxas U K P O Box 1128 Winterbourne Bristol BS36 2SH England Phone 44 117 956 1002 Internet www Traxxas com e mail support Traxxas com Entire contents 2005 Traxxas Traxxas Top Fuel and Ready To Race are trademarks or registered trademarks of Traxxas Other brand names and marks are the property of their respective holders and are used only for purposes of identification No part of this manual may be reproduced or distributed in print or electronic media without the express written permission of Traxxas e This manual covers TRX 3 3 TRX 2 5 and TRX 2 5R Racing Engines Some photos show the engine equipped with optional accessories such as the EZ Start system headers and engine mounts that are not included in the engine package See the end panel of the engine box for exact contents based on your engine model number BEFORE YOU PROCEED SAFETY PRECAUTIONS Carefully read and follow all i
2. du LY 2 Q 2272 RA 2004 SOS PowerTune Head Cylinder Head 5 Le meas Ly D gt LERER 7 57 5 27 2 Ly DISC EEE wate 577 Qu D rey gt 7 AZ X S AR Y Y DEERE 7 D RO DTI 222 mi LEO SEE LOR 2 X 2 2 gt Pull Starter if equipped Fuel Intake Optional Backplate if equipped Air Intake Carburetor Flywheel Crankshaft Crankcase Clutch Bell Throttle Arm not included TRX 3 3 Engine shown Other TRX Racing Engines are very similar You ll find these Nitro R C engine terms throughout this section of the manual 15 15 or 15 refers to the displacement of the engine The TRX 2 5 Racing Engine is 15 cubic inches or 2 5 cubic centimeters cc The name TRX 2 5 is derived from the cc measurement 20 20 or 20 refers to the size of the engine The TRX 3 3 is 20 cubic inches or 3 3 cubic centimeters cc The name TRX 3 3 is derived from the cc measurement ABC Abbreviation for aluminum brass and chrome Refers to engine construction that consists of an aluminum piston that slides in a chrome plated brass sleeve TRX engines use ABC construction Air filter The air filter sits atop the carburetor and prevents harmful dust and dirt from entering the engine Dirt ingestion is the number one cause of premature engine failure so the engine should never be run without the air filter in
3. Choosing a Nitro Percentage A commonly asked question is what is the difference between 10 20 and 33 fuels Increasing the nitro in the fuel is almost like adding extra oxygen to the combustion process It burns more efficiently improves combustion and delivers more power When increased nitro is used more of the other fuel components are then required inside the combustion chamber to maintain the perfect air fuel ratio Therefore overall fuel mixtures TRX ENGINES e 11 need to be richened slightly on the high speed needle about 3 4 of a turn counterclockwise when changing from 2096 to 3396 about 1 2 of a turn counterclockwise when changing from 1096 to 2096 This allows greater fuel flow through the engine and promotes cooler running even at the maximum lean settings If 3396 improves power then it seems that the highest nitro content available beyond 3396 should always be used in the engine In reality there are practical limitations Engines are designed to run best within a range of nitro percentages How the engine is ported the size of the combustion chamber and other factors determine how much nitro can be efficiently used in the engine TRX Racing Engines respond exceptionally well to a maximum of 3396 nitro returning cooler temps more power and a smoother throttle response For those who want to run higher nitro 3396 Top Fuel is the optimum nitro percentage for TRX Racing Engines Increasing the nitro beyond 33
4. PACING I RM A R for High Speed or power when the high the lean side There should always be a light Performance EVERYDAY Seed DUCI stream of blue smoke coming from the exhaust Optimum RUNNING i you lean the high NE d for Climbing 5 Before you begin tuning the engine should be A Low Speed Ue ohe pont bertus warmed up to its normal operating temperature Operation SAFE RANGE l engine cuts out hesitates or and running slightly rich All final tuning sil semen E adjustments must be made to the engine at its normal danger zone and engine operating temperature You can tell the engine is running damage is likely Richen the rich by noting any of the following high speed needle 1 4 turn Sluggish acceleration with blue smoke coming from and retune the exhaust There is unburned fuel spraying from the exhaust tip RICH Leaning the high speed fuel mixture Sluggish Performance increases performance Break In Settings High Speed Fuel Mixture Adjustment With the engine warm and running at a rich setting gradually lean the high speed fuel mixture in 1 16 turn increments Make several high speed passes after each adjustment to clear out the engine and note any change in performance TRX Racing Engines are extremely powerful Remember to apply the throttle gradually to prevent wheelies or loss of control Continue this procedure until there is no longer any performance improvement If any one of the following cond
5. carburetors fuel air mixture at high throttle openings Idle speed The speed rpm the engine runs at when the transmitter s throttle trigger is at neutral Idle speed screw ISS Located on the carburetor body This screw adjusts the idle rpm of the engine Lean A running condition where the engine is not getting enough fuel for the available air Symptoms include engine overheating or the engine runs for a short time and then stalls particularly at high speed This is a dangerous condition that should be corrected immediately or it can ruin your engine Leaning the mixture Turning either the high speed and or low speed needle s clockwise to decrease the amount of fuel the engine receives TERMS TD KNOW Low speed needle LSN Needle valve that controls the fuel mixture at low throttle openings Needle valve Valve consisting of a tapered needle that closes against a corresponding seat to regulate fuel flow Nitro Abbreviation for nitromethane a component of model engine fuel that improves fuel combustion and power output Nitro also refers to a class of R C powered by model engines instead of electric Nitro content The amount of nitromethane used in the fuel Usually measured as a percentage of the total fuel volume Traxxas engines are optimized to use 10 2096 nitro 3396 nitro may be used for racing Nitromethane Nitromethane is a component in the fuel that increases power from the combustion pr
6. 32 for info on clearing a flooded engine and releasing a stuck piston Note It is TRX ENGINES e TROUBLESHOOTING THE TRX RACING ENGINE normal for the engine to be extremely tight and hard to turn when the piston reaches the top of the compression stroke Piston stuck at top dead center see page 32 for info on unsticking the piston Engine extremely sluggish hard to start and will not idle during tank 1 of the break in It is possible that the factory adjusted break in settings on your carburetor are too rich for your geographic location atmospheric conditions or fuel brand Extremes in temperature humidity barometric pressure and altitude can t always be accounted for with a single high speed needle setting The symptoms described above can occur when the air density is very low such as in high mountainous elevations and extremely cold temperatures Under these conditions lean the fuel mixture slightly 1 8 turn and see if there is any improvement in starting and idling Lean the fuel mixture only until the engine will run and idle reliably and then proceed with the break in The contents of different brands of fuel other than Traxxas Top Fuel in combination with extreme atmospheric conditions can also make the factory preset break in settings too rich and cause the symptoms described above Again try leaning the fuel mixture slightly 1 8 turn to see if there is any improvement in starting and idling Clearing a
7. The engine clutch exhaust system and starter assembly is now ready for installation into the chassis 1602 Follow the instructions for the proper break in procedure of a new TRX Racing Engine page 19 TRX ENGINES 41 TRX ENGINES e 42 20 7 ABC 7 19 After run Procedure 34 35 Air Filter 5 6 7 8 14 filter foam 8 Air Intake 6 Backplate 6 Break in 7 19 20 21 22 23 Tank 1 21 Tank 2 21 Tank 3 22 Tank 4 22 Tank 5 22 Tank 6 23 Carburetor 6 7 Carb 7 factory settings 16 slide 10 Clean out 7 Clutch Bell 6 Combustion chamber 7 Connecting rod 7 Cooling fins 8 Crankcase 6 7 Crankshaft 6 7 Cylinder head 8 head protector 6 PowerTune head 6 Dyno 8 EZ Start 8 Fit 8 Flame out 8 Flywheel 6 Fuel 8 intake 6 tubing 8 Fuel Mixture 8 high speed mixture See High Speed Fuel Mixture Adjustment lean 9 17 18 leaning 9 low speed mixture See Low Speed Fuel Mixture Adjustment rich 10 18 Glow plug 8 driver 8 Header 9 High Speed Fuel Mixture Adjustment 25 high speed needle 6 9 Idle Speed 9 26 idle speed screw 6 9 Low Speed Fuel Mixture Adjustment 26 low speed needle 6 9 Maintaining and Storing 33 Needle valve 9 Nitro 9 O ring 9 Piston 9 Port 10 Priming 10 Pull Starter 6 Safety 4 Sleeve 10 Stall 10 Starting 20 Throttle Arm 6 Top dead center TDC 10 30 32 Troubleshooting 29 clearing a flood 31 Tuned p
8. at all times knowledgeable adult TRX Racing Engines are the next generation of TRX nitro power The larger displacement and advanced porting generate class leading horsepower while still maintaining the TRX Racing Engine characteristics of broad linear power delivery and ease of tuning Focused engineering and rigorous testing have yielded unprecedented power and uncompromising performance that turns ready to run into Ready To Race TRX Racing Engines take a total system approach Each part of the engine from the air filter to the exhaust tip is carefully engineered to work in harmony with other engine components Each part complements the next to extract maximum power TRX Racing Engines are designed to be tolerant of variations in tuning and running through a wide range of variable atmospheric conditions such as changes in temperature humidity and altitude TRX Racing Engines are manufactured to exacting tolerances and requires a specially designed break in procedure to accomplish the final precision fitting of the internal engine components It is very important that you follow the new break in procedure as closely as possible to achieve the best performance and longest life from your TRX Racing Engine Old style break in procedures such as simply running the engine with a very rich fuel mixture for the first 4 tanks of fuel will not achieve the best results Follow the steps in this manual to successfully break in your TRX Ra
9. engine back to a satisfactory state of tune based on how it sounds and performs always with a visible stream of blue smoke coming from the exhaust If engine temperature is exceeding 270 F with proper cooling and no signs of abnormal running then avoid running the engine at its maximum lean setting Watch closely for any signs of TROUBLESHOOTING THE TRX RACING ENGINE overheating Richen the fuel mixture slightly to provide a safety margin of additional cooling lubrication Symptoms of overheating include Steam or smoke coming from the engine not exhaust Hesitation or stalling during acceleration Popping or clattering sound when decelerating detonation Fluctuating idle speed The following section addresses some very basic engine and radio questions you may have about your TRX Racing Engine Most questions arise from simple user errors or minor adjustments that are easy to correct If you can t find a solution for your TRX Racing Engine here visit our web site at Traxxas com and click on the Customer Support menu There you will find a much more extensive and detailed online troubleshooting area In addition you may call Traxxas Customer Service at 1 888 TRAXXAS outside the U S call 972 265 8000 Engine spins but will not start If you re using a glow plug igniter make sure it s fully charged and connecting properly to the glow plug If the igniter is fully charged then replace the glow plug It is normal for glow
10. higher or lower than your baseline setting see page 16 for detailed info on how air density affects mixture settings Humidity Lower Slightly more dense Slightly richer Higher Slightly less dense Slightly leaner Pressure barometer Lower Less dense Leaner Higher More dense Richer Temperature Lower More dense Richer Higher Less dense Leaner Altitude Lower More dense Richer Higher Less dense Leaner Nitro 96 Lower Leaner Higher Richer TRX ENGINES e 27 TUNING THE TRX RACING ENGINE There is NO optimal temperature that can be used as a target to deliver the best engine tuning Do not rely on a temp gauge alone to tune your engine Tune the engine by paying very close attention to how it responds to changes in fuel mixture more smoke less smoke fast sluggish reliable stalling smooth sound muffled sound etc Once the engine is tuned then observe the temperature TRX ENGINES e 28 Tuning the Engine by Temperature The following procedures require an optional infrared temperature probe or on board temperature gauge Traxxas on board digital temperature gauge part 4091 Engine temperature can be used as an effective tuning aid when you understand the relationship between engine temperature and ambient temperature The engine operating temperature when tuned for maximum performance will vary according to atmospheric conditions engine load gauge accuracy and many other factors The atmospheric condition that has
11. not install the cooling head until these two items are keyed into each other Place the stock copper head gasket onto the sleeve and fit the cooling head into the sleeve Note that there are two slots notched through the cooling fins on each side of the cylinder head These slots are for access to the engine mounting screws The five head bolts should line up with the five holes on top of the engine case and the access slots on the cooling head should line up with the slots manufactured into the crankcase see picture 1002 for orientation Be careful not to damage the copper head gasket While pressing the head squarely onto the sleeve thread the head bolts into the engine case just until they stop Do not tighten down these bolts individually It is very important to attain even pressure around the cooling head Slowly tighten each screw just a little at a time in a crossing pattern see picture 1003 until each bolt becomes snug Tighten each bolt in the same pattern to 9 11inslbs of torque TRX ENGINES 39 REBUILDING THE TRX RACING ENGINE TRX ENGINES e 40 1 1 Inspect the backplate bushing and starter shaft for wear and clean them with denatured alcohol Fasten the backplate with the starter shaft to the crankcase Important The reliefs that are manufactured into the backplate must line up to match the ports inside of the engine case see picture 1101 for orientation Key the starter shaft to the crank pin by slowly r
12. people 16 If you still have problems contact Traxxas Customer Support at 1 888 TRAXXAS or have differing opinions on support traxxas com what is the proper procedure to break in a model engine Only use the 1 Drive the model with the body off Traxxas break in procedure 2 Driving procedure Gently pull the throttle trigger to about 1 4 throttle over a 2 second Other break in procedures could result in a weak damaged or otherwise poor performing engine The procedure outlined here count Then gently apply the brake to stop Count the two seconds out while accelerating one thousand one one thousand two and then stop Operate the throttle trigger as smoothly as you can Repeat this starting and stopping procedure until the first tank of fuel is nearly empty was extensively tested and 3 Look for thick blue smoke exiting the exhaust outlet If there is no smoke richen the proven to yield better high speed needle 1 4 turn by turning the needle counterclockwise performing engines than 4 When the fuel tank is nearly empty shut off the engine by pinching the fuel line connected other common break in methods Even if you have years of experience using model engines please do not ignore this caution to the carburetor use the installed clamp 5 Let the engine cool for 15 minutes Note If at any point the engine cuts out or stalls during gentle acceleration richen the high speed needle 1 4 turn by turning the needle
13. place BDC Bottom dead center The bottom most position of the engine piston stroke Break in Break in is the procedure for running a brand new engine according to specific instructions This correctly prepares the engine for normal running The break in procedure can be different for different Carb Abbreviation for carburetor Carburetor The carburetor atomizes mixes Clean out Cleaning out is a condition that Combustion chamber The combustion Connecting rod The connecting rod Crankcase The engine s body that contains TERMS TD KNOW makes of engines Follow the Traxxas directions for break in exactly the fuel with the air so that the engine can burn it There are two types of carburetors slide carbs and barrel carbs TRX engines use the superior slide carburetor design occurs when the engine is accelerating and the fuel mixture becomes sufficiently lean to allow the engine to continue into its upper rpm power band It is usually characterized by a noticeable decrease in blue exhaust smoke and a dramatic increase in engine speed chamber is machined into the bottom of the cylinder head This is where the glow plug ignites the fuel The shape of the combustion chamber is designed to promote more efficient burning of the fuel transfers the piston motion to the crankshaft TRX Racing Engines use a knife edged connecting rod The aerodynamic sharpened edges allow it to slice through the pr
14. 901 Line up the wrist pin bore in the rod with the wrist pin bore in the piston and slide the wrist pin through the larger opening in the piston Note that the closed end of the wrist pin should be inserted first into the opening The orientation of the wrist pin helps keep the wrist pin cool Install the wrist pin clip into the groove of the piston s wrist pin bore 902 This will retain the wrist pin inside of the piston Caution Do not allow the pliers to scratch the piston and make sure that the clip expands into the groove Lower the piston and connecting rod assembly into the top of the engine case with the oil hole of the connecting rod facing toward the crankshaft Apply a drop of oil onto the crank pin before installing the connecting rod onto the crank pin Slide the connecting rod over the crank pin and rotate the crank pin to the bottom center of the crankcase 903 REBUILDING THE TRX RAGING ENGINE 10 Lube the outside of the piston with after run oil and make sure the crank is at BDC bottom dead center then slowly lower the sleeve until It is just above the piston Rotate the crank slowly to bring the piston into the Sleeve If there is any resistance stop Repeat until the piston moves smoothly into the sleeve Bring the piston close to TDC then push the sleeve in fully Important The slot in the lip at the back of the sleeve must key into the pin at the back of the crankcase opening 1001 Do
15. 96 can introduce the need for engine modifications ports head shimming etc to avoid starting and tuning difficulties There are limits to how much nitro an engine can effectively use to make more power Lower nitro percentages have their own advantages Nitro is an expensive component in the fuel so 1096 nitro blend is more economical for the sport user 1096 also provides greater latitude with the needle settings for easier tuning When using Traxxas Top Fuel using higher nitro percentages does not cause the engine to wear out faster 3396 Top Fuel contains the same quality lubrication package as 10 and 2096 Top Fuel Some non Traxxas high percentage nitro racing fuels do sacrifice some lubrication in attempts to increase performance We urge you to not take chances with your engine investment and use Top Fuel for consistent performance and long engine life What about Other Fuels Can other brands of fuel be used besides Top Fuel There are other fuels that can provide satisfactory performance however there could be long term costs in the form of decreased engine performance loss of tuning ease and shorter engine life Only use fuels that contain both castor and synthetic oil Everyone has an opinion or a claim to make about fuel The engineering team at Traxxas has spent years developing TRX Racing Engines No one knows more about the specific fuel requirements of Traxxas engines than Traxxas engineers We strongly urge you not to take c
16. A rubber filter base 2 A plastic housing consisting of a permanently assembled mesh cap and body 3 An oiled foam element Ci This includes the break in time Clean your air filter after break in Dust which is often too fine to see and dirt constantly move through the filter anytime the engine is running Even if you can t see dirt on the filter it is present inside the foam after any amount of run time If you exceed the recommended cleaning intervals your engine will be damaged Engine damage or wear due to dirt ingestion is easy to detect and one of the top causes of premature engine failure Air Filter Cleaning Instructions 1 Remove the air filter from the carburetor bore by pulling the entire filter assembly firmly to the side to release it Do not pull straight up 2 Disassemble the filter Pull the rubber air filter neck out of the filter body With the base removed the foam element is visible in the bottom of the filter body Pull out the foam element 3 Clean the filter parts by thoroughly washing all three pieces of the filter assembly in hot soapy water dishwashing detergent works well Repeat twice THE AIR FILTER 4 Thoroughly dry the parts with a clean towel or compressed air Remember to wear your safety glasses when working with compressed air 5 Oil the foam element with foam filter oil Use the supplied Traxxas filter oil part 5263 or a high quality special purpose foam filter oil like what is
17. Always wear eye protection when using compressed air or spray cleaners and lubricants TRX ENGINES 33 If the engine is worn or damaged enough to require replacing the piston sleeve or connecting rod consider exchanging your old engine for a brand new engine under the terms of the Traxxas Lifetime Engine Replacement Plan ERP It could save you time and effort Details are in your documentation package or on Traxxas com Denatured alcohol available from home centers and paint supply stores in a spray bottle is an extremely effective cleaner Be sure to wear safety glasses and gloves when working with denatured alcohol Follow all precautions on the product labeling TRX ENGINES 34 MAINTAINING THE TRX RACING ENGINE After run Procedure You must perform after run maintenance on your Traxxas engine whenever the model will be stored for longer than a few hours Taking the time to prepare your engine for storage will reward you with longer engine life easier starting and better performance When a nitro engine is shut off some excess unburned fuel remains in the engine The methanol in model engine fuel is hygroscopic which means it easily attracts and absorbs moisture This moisture can cause rust and corrosion on the steel engine parts crankshaft bearings wrist pin and starter shaft if the fuel is not removed from the engine There are after run oil products available from your hobby dealer or you can us
18. Flooded Engine If the engine is primed for too long during startup it can become flooded with fuel When the engine is flooded it will no longer turn due to excess fuel in the combustion chamber preventing upward movement of the piston Use the following procedure to clear a flooded engine 1 Remove the glow plug and gasket with the glow plug wrench supplied with your model A 5 16 8mm nut driver will also work Turn the model upside down Pull the starter handle several times to clear the engine of excess fuel Turn the model over and reinstall the glow plug and gasket Do not prime the engine Apply 1 2 throttle and pull the starter The engine should start immediately poe meg TRX ENGINES e 31 TROUBLESHOOTING THE TRX RACING ENGINE TRX ENGINES 32 Piston stuck at top dead center TDC Top dead center is the position where the piston is at the very top of the tapered sleeve Occasionally an engine can get stuck at this position This is most likely to happen on new engines during break in but can also happen at other times If the engine is stuck at TDC use the following procedure to release the piston from the sleeve 1 Remove the glow plug using a 8mm 5 16 nut driver and verify that the piston is at the top of its stroke 2 Locate the flywheel at the front of the engine it looks like a silver 50 cent piece with serrated edges Part of the flywheel is obscured beneath the carburetor
19. RX RACING ENGINE TRX ENGINES 38 6 Flush the crankcase and bearings out with out with denatured alcohol or electric motor spray Dry the crankcase with compressed air 601 Caution Do not let the compressed air A spin the bearings and always use eye protection when using compressed air Inspect the crankcase and bearings for damage or missing parts Make sure that the bearing cages are not broken and check for corrosion inside of the crankcase The bearings should feel smooth and have little play Make sure Y the bearings spin freely and that there are no particles or grit in them Replace the bearings if there are any signs of damage Inspect the exhaust O ring gasket and the backplate O ring gasket for tears 602 Replace these O rings if needed 7 Apply few drops of machine oil or after run oil to the bearings Inspect the crankshaft for corrosion and also check for scratches or score marks around the intake port of the crankshaft see arrow Check the crank pin for wear 701 The connecting rod should fit and rotate smoothly on the crank with no play between the rod and the crank pin If there is play between a NEW connecting rod and the crank pin then the crank pin is worn and the crankshaft will need to be replaced Important Do not reuse a damaged or worn crankshaft This will dramatically shorten the life of your rebuilt engine If there are damaged or worn parts beyond the pis
20. ay be very difficult to start and tune at those extremely cold temperatures Also at temperatures below freezing nitro fuel can actually begin to gel up and this can be harmful to the engine Follow the remaining break in procedures as outlined in this owner s manual This along with the steps listed above will ensure a good break in for your new nitro engine and provide many hours of enjoyment The engine s performance depends on the fuel mixture Turn the mixture needles clockwise to lean the fuel mixture and counterclockwise to richen it Leaning the me mixture will increase engine power up to the ee s mechanical limits a engine I Leaning the engine beyond the safe allowable limits will result in poor performance and almost certain engine damage Indications of an overly lean mixture include e leratio Overheating temperature beyond 270 F at the glow plug Little or no blue smoke coming from the exhaust TRX ENGINES Z4 TUNING THE TRX RAGING ENGINE If any of these conditions are present stop immediately High Speed Power Loss and richen the high speed mixture 1 4 turn The engine Overheating will probably be slightly rich at that setting and you LEAN When tuning for can then retune for performance Always tune for performance watch closely performance by starting rich and moving leaner Cutting out stalling NUS oes co aL s bu toward the ideal setting Never try to tune from Optimum
21. bove conditions occur richen the fuel mixture to the optimum setting by richening the high speed needle at least 1 8 turn counterclockwise and retest This setting will extend engine component life Low Speed Fuel Mixture Adjustment The low speed mixture is always set after the high speed needle is correctly adjusted Set the low speed mixture using the following pinch test 1 Oncethe engine is warm do several high speed runs to confirm that the high speed needle is set correctly 2 Bring the vehicle in and pinch closed the fuel line going into the carburetor The engine should run for 2 3 seconds speed up and then die 3 If the engine runs longer than 3 seconds then lean the low speed needle 1 16 turn make several more high speed runs and retest 4 If the engine dies immediately without speeding up then richen the low speed needle 1 8 turn make several more high speed runs and retest When the low speed needle is set correctly the engine s throttle response should be very quick Idle Speed Adjustment Once the high and low speed mixtures have been set reduce the idle speed to the minimum reliable idle speed Remember this adjustment should be made while the engine is running at normal operating temperature 1 Turn the throttle trim on the transmitter so that the brakes are applied This ensures that the throttle slide is resting against the idle adjustment screw TUNING THE TRX RACING ENGINE 2 If necessary remove
22. but part of it is accessible from the top side This is the part of the flywheel where the procedure is performed 3 Use a flat blade screwdriver to rotate the flywheel Place the blade of the driver into one of the grooves of the flywheel and push down turning the flywheel counter clockwise when viewed from the front You should see the flywheel turn and the piston should become unstuck from the sleeve T Maxx and Revo Place the blade of the driver through the opening of the chassis beneath the flywheel Place the edge of the blade into one of the grooves of the flywheel and rotate counter clockwise when viewed from the front using the chassis for leverage 4 Put two or three drops of light machine oil into the glow plug hole to lubricate the piston and sleeve Do not use too much oil It will hydro lock the engine Verify the starter will spin the engine with the glow plug out 5 Rotate the flywheel so the piston is at bottom dead center and replace the glow plug with gasket 6 You should now be able to start the engine Bottom Dead Center MAINTAINING THE TRX RACING ENGINE Your TRX Racing Engine requires timely maintenance in order to stay in top running condition Neglecting maintenance could allow dirt deposits and moisture to build up inside the engine leading to internal engine failure Follow proper maintenance and storage procedures to avoid damage to your engine The following procedures should be taken very seriou
23. by the number of turns the needles are turned out from fully closed The fuel mixture settings have been pre set from the factory to typical break in settings Do not readjust your carburetor from the factory settings until after the engine is started and running and you have been able to observe the engine running to assess what minor adjustments may be required to compensate for fuel temperature and altitude Adjustments are usually made in 1 8 or 1 16 turn increments The Idle Speed Adjustment The idle speed screw controls the closed position of the throttle slide When the throttle servo is in its neutral position the throttle slide should be stopped against the idle adjustment screw Always use the idle speed adjusting screw to control engine idle Do not use the throttle trim on the transmitter to adjust idle speed The idle speed should be set as low as possible and still maintain reliable running BREAKING IN THE TRX RACING ENGINE TRX Racing Engines use a ringless aluminum brass chrome ABC piston sleeve construction This type of engine design relies on a very precise running fit between the piston and sleeve for cylinder sealing Engine break in is necessary to allow the piston and sleeve to develop an extremely precise fit and optimum cylinder sealing Therefore proper engine break in is critical to achieving the fastest most reliable engine performance Allow yourself about 1 to 1 2 hours to complete the break in procedure T
24. celerate from would be 90 and so on idle the throttle opens and the low speed needle is pulled away from the needle seat This allows more fuel to flow with the increased air flow As the throttle is increased the low speed needle is pulled completely away from the needle seat leaving it fully open At that point fuel metering is entirely controlled by the high speed needle Again using our water hose example when the spray nozzle at the end of our garden hose is fully open then the main water valve can be used to adjust how fast the water flows The engine s performance is directly linked to the fuel mixture Richening the fuel mixture increases the amount of fuel in the air fuel mixture ratio and leaning the fuel mixture decreases the amount of fuel in the air fuel mixture ratio Slightly rich fuel mixtures deliver cooler Slightly lean fuel mixtures deliver stronger running and more lubrication but with more efficient combustion and more power slightly less power but with less lubrication TRX ENGINES 17 THE CARBURETOR TRX ENGINES 18 Tuning the engine means finding the perfect balance between the two excellent power to meet your needs while maintaining good lubrication for long engine life The optimal fuel mixture setting is rich to provide a safety margin against having a lean condition if some variable changes such as the temperature from one day to the next General fuel mixture settings are measured
25. cing Engine A routine maintenance schedule is also required to keep your TRX Racing Engine in top running condition Cleaning the air filter after each hour of running is particularly important Also it is extremely important to perform after run maintenance on the engine to prevent corrosion of the internal engine components see page 34 INTRODUCTION Traxxas strongly discourages changing modifying any part of your TRX Racing Engine Old tech tips and tricks that may have boosted the power of other engines could seriously diminish the performance of your TRX Racing Engine There s more advanced thinking development and testing in the stock parts of your TRX Racing Engine than in many aftermarket manufacturer s so called performance parts TRX Racing Engines are already some of the most powerful engines in their class and simply will not benefit from average low tech aftermarket bolt on performance items TRX ENGINES 5 TRX RACING ENGINE ILLUSTRATED Air Filter Housing TRX ENGINES e 6 Head Protector 7 LER meas 74 S LLZ D Case LLZ Le 577 LA 22 LOR was LES 577 7 LDS 222 TRL 2227 Air Filter Base v LD LEER dp Lk Q wea d Glow Plug LL LER gt re 470 Db v zy gt wea 2 SOK gt gt gt LS e 57 eeu wee p 77 v ZZ 9 Gy 2
26. counterclockwise Ta 1 From tank 2 forward model should be driven with the body on 2 Driving procedure Gently pull the throttle trigger to about 1 2 throttle over a 2 second count Then gently apply the brake to stop Count the two seconds out while accelerating one thousand one one thousand two and then stop Repeat this starting and stopping procedure until the second tank of fuel is nearly empty 3 When the fuel tank is nearly empty shut off the engine and let it cool for 15 minutes 24 BREAKING IN THE TRX RACING ENGINE TRX ENGINES ZZ 1 Driving procedure Gently pull the throttle trigger to 1 2 throttle over a 3 second count Then gently apply the brake to stop Count the three seconds out while accelerating one thousand one one thousand two one thousand three and then stop Repeat this starting and stopping procedure until the third tank of fuel is nearly empty 2 As the engine loosens the idle speed may increase and cause the model to try to creep forward when stopped Reduce the idle speed by turning the idle adjustment screw see page 6 on the carburetor counterclockwise 3 When the fuel tank is nearly empty shut off the engine and refuel From here on you do not need to let the engine cool between tanks 1 Driving procedure Gently pull the throttle trigger to full throttle over a 3 second count Then gently apply the brake to stop Count the three seconds out while accelerating
27. e crankshaft and engine bearings are made to extremely high quality standards should under normal circumstances outlast multiple sets of pistons sleeves connecting rods and wrist pins reciprocating assemblies It could be more economical for you to continue to use your good bearings and crankshafts and simply replace the reciprocating assembly as needed Engine assembly is not difficult and replacing the reciprocating assembly does not require any special tools or skills TRX ENGINES 35 REBUILDING THE TRX RACING ENGINE i TRX ENGINES 36 thoroughly before disassembly These the TRX Racing Engine once the engine has been removed from the chassis These instructions were performed on a TRX 3 3 engine equipped with the EZ Start electric starting system and Revo exhaust system Other TRX Racing Engines and engines equipped with pull starters or backplates without starter are similar These instructions are for the rebuilding of 201 l T It is very important to clean the exterior of the engine and EZ Start system instructions show you how to replace the entire internal reciprocating assembly The following instructions are for engines equipped with IPS crankshafts using Traxxas clutch components For multi shaft crankshafts in non Traxxas applications follow the manufacturer s directions for clutch installation removal 1 Start by removing the exhaust pipe and header from the engine b
28. e WD 40 a common household lubricant To ensure your TRX Racing Engine is protected from internal corrosion use the following procedure 1 Shutoffthe engine by pinching the fuel line closed This allows most of the excess fuel to be consumed by the engine Be sure the throttle is in the idle position You may have to pinch the fuel line closed for several seconds before the engine stops 2 Completely empty the fuel tank Use your fuel dispensing bottle to suck out the old fuel Do not mix the old fuel with your fresh fuel supply If you leave fuel in the tank transporting or handling your model may cause fuel to run into the engine 3 With the fuel tank empty and the throttle at the idle position try to start the engine The engine will most likely start and run for a few seconds as it uses up any fuel remaining in the engine and fuel lines 4 Oncethe engine stops clean the outside of the engine with compressed air or spray motor cleaner Once the engine is clean and dry remove the blue glow plug power wire glow plug and air filter 5 Open the throttle fully and spray a one second burst of WD 40 into the carburetor and into the glow plug hole Caution Wear safety glasses to prevent spray from getting into your eyes 6 Place a or paper towel over the engine to catch any WD 40 that may come out the carburetor or glow plug hole MAINTAINING THE TRX RACING ENGINE 7 Crankthe engine with the EZ Start or pull the s
29. each side the clutch bell and slide the clutch bell over the pilot shaft followed by the 5x8x0 5TW 1401 Fasten the 5 0 E clip wearing safety glasses around the pilot shaft to retain the clutch assembly Note The Nitro 4 Tec will need two 5x8x0 5TW placed onto the pilot shaft before the installation of the clutch bell then secure the assembly with the 3x10CS screw REBUILDING THE TRX RACING ENGINE Shaft 1 5 Clean the roller clutch with denatured alcohol or electric motor spray and lube the roller clutch with Mobil 19 5W30 oil L Slide the Teflon washer and LO roller clutch onto the starter shaft as shown 1501 Note The roller clutch is to be installed onto the starter i shaft so that the clutch engages the starter shaft clockwise and rotates freely counter clockwise The engraved text on the roller clutch faces the engine backplate for correct rotation Slide the EZ Start system or pull start onto the starter shaft that exits the backplate of the engine Line up the drive with the roller clutch Fasten the EZ Start gear case to the backplate with three 3x12BCS screws 1502 or the pull starter with four 3x12BCS 1 6 Inspect the exhaust O ring and replace it if it is damaged Fasten the exhaust header and pipe assembly back onto the rear of the engine case with the two 3x15CS screws 1601 17 Reinstall the head protector requires five 3x8CCS the TRX 3 3
30. essively rich mixtures cause the engine to have sluggish performance with exaggerated blue smoke and unburned fuel coming from the exhaust rpm Abbreviation for revolutions per minute how many times the engine crankshaft spins in a minute Sleeve Internal engine part that contains the piston The precise fit between the sleeve and the piston creates a seal that allows engine to have the required compression for combustion The sleeve in a TRX engine is made of brass and is then hard chrome plated Slide carburetor The throttle on a slide carburetor closes and opens by sliding a barrel in and out of the carburetor body This type of carburetor is preferred for performance use because it provides a less restrictive straight through air path than the barrel carburetor design Stall When the engine stops running usually due to an incorrect fuel mixture setting or running out of fuel TDC Top dead center The top most position of the engine piston stroke Tuned pipe The tuned exhaust pipe usually consists of a specially shaped metal or composite chamber with baffles that is designed to enhance the power output of the engine Wear in Fitment process that occurs during engine break in where internal engine parts develop an even more precise matched fit through actual use under controlled circumstances WOT Abbreviation for wide open throttle THE FUEL Use the Right Fuel It s imperative that you use the cor
31. essurized air fuel mixture inside the crankcase all of the running mechanical components TRX ENGINES e 7 TERMS TO KNOW Crankshaft The main shaft of the engine that and the engine will have good sealing and holds the reciprocating assembly compression If the fit is loose compression Cooling fins The cooling fins are milled into will be low and both the piston and sleeve the cylinder head and crankcase and cause should be replaced heat to be drawn away from the engine Heat Flame out Occurs when the engine stops is removed when it dissipates into the air running at high rpm Usually the fault of passing across the cooling fins It is important excessively lean fuel mixture or glow to keep the fins clean of dirt and debris for plug failure maximum cooling efficiency Fuel 1096 2096 3396 The engine must have Cylinder head head The finned aluminum model engine fuel to run Traxxas Top Fuel part on top of the engine that is responsible is recommended Fuel is sold in quarts and for dissipating most of the engine s heat The gallons from hobby dealers The 1096 2096 combustion chamber is machined into the and 33 labeling refers to the percentage bottom of the head of nitromethane contained in the fuel see Dyno Abbreviation for dynamometer A nitro percentage definition precise piece of testing equipment that Fuel mixture The ratio of fuel to air as accurately measures engine power and determi
32. hances with your engine investment and use the Traxxas fuel made for TRX Racing Engines Handling the Fuel Follow all directions and warnings on the fuel can Keep the fuel tightly capped at all times Some components in the fuel can evaporate very quickly and upset the balance of the fuel Do not store unused fuel in the fuel dispenser Immediately return fresh unused fuel back into the fuel can Do not mix old and new fuel Never mix different fuel brands together Store the fuel in a cool dry location away from any source of heat ignition or combustion Read and follow the safety precautions on page 4 in this manual THE AIR FILTER Clean your air filter after every hour of runtime to avoid engine damage even if the filter looks clean Ifyou use compressed air to dry your air filter assembly wear Safety glasses and avoid directing compressed air toward your skin If foam filter oil is not available clean 30 or 40 weight motor oil can be substituted but is not preferred Never run the engine without a properly oiled filter TRX ENGINES 14 The TRX Racing Engine air filter is specifically designed to deliver maximum performance while protecting your engine from dust and dirt Use only the supplied filter You will not improve engine performance by switching to an aftermarket filter and you may risk engine damage due to poor filtration The TRX Racing Engine air filter assembly consists of 3 pieces 1
33. he engine break in period will take 5 tanks of fuel The break in time is not the time to impress your friends with your new engine You must wait until the engine is fully broken in before attempting sustained high speed running Patience and careful attention during break in will reward you with the best performing TRX Racing Engine possible During break in your engine may appear to malfunction with symptoms like stalling inconsistent performance and fouled glow plugs These are simply the normal break in pains engines sometimes go through They will disappear once your engine is fully broken in Many owners report not experiencing any of these symptoms with TRX Racing Engines We recommend replacing the glow plug with a new one after the engine break in procedure Engine Break in Procedure The focus during break in is to vary and limit the engine speed This will be accomplished by accelerating and stopping at different rates for the first 5 tanks of fuel As the engine begins to break in the duration and intensity of the acceleration will gradually increase Sustained high speed running is not permitted until the 6th tank of fuel Perform the initial break in on a large flat paved surface Apply all throttle and braking actions gently Abrupt acceleration or braking could cause the engine to stall unnecessarily Never run your model indoors Since model engine exhaust fumes are harmful always run your model outdoors in a
34. he four 3x6CS 3x6BCS on engines equipped with non starter backplate screws from the backplate of the engine and pull the backplate from the crankcase 301 Remove the head protector requires removal of five 3x8CCS on the TRX 3 3 Remove the cooling head from the engine case by removing the five 3x12CS head bolts 302 Be careful not to lose or damage the copper head gasket If the head gasket is damaged replace it with a new one 4 Locate the bottom of the sleeve through the rear opening of the crankcase Press the bottom of the sleeve upward with a plastic or wooden stick 401 this is to prevent internal damage to the crankcase The sleeve should slide up and out of the crankcase 402 REBUILDING THE TRX RAGING ENGINE Rotate the crank to where the connecting rod and piston are located at TDC top dead center 403 Gently pull on the bottom of the connecting rod with needle nose pliers sliding the rod off of the crank pin 403 Be careful not to damage the connecting rod if it is being reused The rod and piston assembly will exit the top of the crankcase 404 5 Push the end of the pilot shaft through the crankcase The crankshaft should exit the rear of the crankcase 501 Loosen the 3 0NL just below the base of the carburetor 502 Slide the carburetor up and out of the crankcase 503 Now the crankcase is ready to be flushed clean and inspected TRX ENGINES e 37 REBUILDING THE T
35. ipe 10 Tuning 24 by temperature 28 fine tuning 27 Wear in 10 WOT 10 TRX ENGINES 43 lf Y cI gl 7 yg9g 7 g9 X WHERE POWER MEETS TECHNOLOGY 100 KLEIN ROAD PLANO TExAs 75074 VENENIS 1 888 TRAXXAS
36. itions occurs the fuel mixture is already past the maximum safe lean setting 1 There is no longer any performance improvement 2 The engine begins to cut out at high speed Danger 3 There is a sudden loss of power during acceleration Danger TRX ENGINES e 25 TUNING THE TRX RACING ENGINE For your convenience the low speed needle has a positive stop that prevents it from being over tightened and damaging the needle and seat This also provides an easy way to gauge how many turns out from closed the low speed needle adjustment is set to 7 When adjusting the low speed fuel mixture it is very important to make several high speed runs with your model between adjustments to clear out any excess fuel Perform the pinch test immediately after If the engine is allowed to idle for a long period of time it could load up with fuel and give you an inaccurate measurement from your pinch test TRX ENGINES e 26 4 The engine begins to overheat Symptoms of overheating include Fluctuating idle speed Temperature measurement above 270 F Hesitation or stalling during acceleration at the glow plug A temperature reading Steam or smoke coming from the engine above 270 alone does not necessarily not exhaust indicate overheating Look for other Popping or clattering sound when symptoms of overheating combined with decelerating detonation temperature for a more accurate warning If any of the a
37. ld Air more dense THE CARBURETOR Water Valve The amount of fuel metered and atomized by Controls Overall Flow See Tuning Your TRX Racing the carburetor is controlled by the two mixture High Speed Needle 99 Engine starting on page 24 for complete information on adjusting the air fuel mixture and idle speed needles the high speed needle and the low speed needle The low speed needle is used to meter the fuel used by the engine at idle and low rpm part throttle The high speed needle is used to meter the fuel when the throttle is open from part throttle to wide open throttle WOT These two needles provide precise control of the Low Speed Needle air fuel ratio across the engine s entire rom range The maximum possible fuel flow is always controlled by the high speed needle It works like the main water valve on a garden hose Turn it clockwise to close the valve counter clockwise to M Water Nozzle Controls Fine Flow A turn refers to tightening turning loosening turning out mixture needles A full turn refers to turning the open it When the throttle is at idle or partially open the low speed needle meters the fuel flow needle 360 so a 1 2 turn at the outlet needle seat where the fuel enters the carburetor venturi This second valve acts would be 180 a 1 4 turn like the spray nozzle at the end of the garden hose in our example When you ac
38. may also e mail customer RACING ENGINE support with your question at support Traxxas com Join thousands of Traxxas R C REBUILDING THE TRX enthusiasts in our online community at www Traxxas com RACING ENGINE Traxxas offers a full service on site repair facility to handle any of your Traxxas service needs Maintenance and replacement parts may be purchased directly from Traxxas or you can save shipping and handling costs by purchasing them from your local hobby dealer 42 INDEX TRX ENGINES 3 SAFETY PRECAUTIONS L All of us at Traxxas want you to safely enjoy your new TRX Racing Engine Operate your TRX All instructions and Racing Engine sensibly and with care and it will be exciting safe and fun for you and those precautions outlined in around you Failure to operate your TRX Racing Engine in a safe and responsible manner may this manual should be result in property damage and serious injury The precautions outlined in this manual should be strictly followed to ensure strictly followed to help ensure safe operation You alone must see that the instructions are safe operation of your followed and the precautions a are adhered to TRX Racing Engine Me oisonous Always follow all directions and precautions printed on the fuel container Model engine fuel is poisonous to humans and animals Drinking the fuel can cause blindness and death Handle with care and respect Model engine fuel especially when i in a fuel dis
39. ned by the needle settings of torque output over the engine s entire the carburetor rpm range Fuel tubing fuel line The thick silicone EZ Start Traxxas on board electric starting tubing that carries fuel from the fuel tank system The system consists of a hand held to the carburetor Starter control unit and an on board gearbox Glow plug The glow plug is located in the with an electric motor to spin the engine cylinder head at the top of the combustion Filter foam The oiled foam element inside the chamber It contains an element that glows air filter housing The filter foam in the engine hot when voltage is applied When the must be thoroughly cleaned and re oiled engine is being started the heat from the after every hour of run time glow plug ignites the fuel mixture and starts Fit Usually refers to the fit of the piston and the combustion process Sleeve If the fit is tight the piston will feel very Glow plug driver This tool clips onto the glow tight at top of the sleeve top dead center plug and supplies the required voltage to TRX ENGINES amp light the glow plug element It is also called an igniter EZ Start equipped engines do not require this separate tool Header The aluminum tube that connects the exhaust system to the engine exhaust port The length and diameter of the header must be carefully selected to extract the most power from the engine High speed needle HSN Adjusts the
40. ng Engine for the first time make sure you have read all instructions and precautions in this manual Pay close attention to the tank by tank break in instructions in the next section and make sure you have read and understood them before you run your engine Your engine must be at room temperature 70 F or 21 C or above the first time you start it If it s cooler than room temperature outside keep your TRX Racing Engine indoors until you re ready to start it then take it outside 1 Turn on the radio system 2 Make sure the throttle is in the idle position 3 Pull the starter handle with quick short continuous pulls and watch for fuel moving through the fuel line up to the carburetor Watch closely The fuel moves very fast If the fuel doesn t move through the line within 5 seconds prime the engine by briefly one or two seconds covering the exhaust outlet until the fuel is just visible in the carburetor fuel line Watch carefully If the engine is primed too long it will flood with fuel and stop turning TRX ENGINES 20 BREAKING IN THE TRX RACING ENGINE 5 Once fuel reaches the carburetor the engine should quickly start and idle 6 Proceed with the engine break in As you gain experience in If your engine doesn t start refer to the TRX Racing Engine troubleshooting section at the hobby you may www Traxxas com support If your factory fuel mixture settings have been altered refer to page discover that many
41. nstructions in this and any accompanying materials to prevent serious damage to your engine Failure to follow these instructions will be considered abuse and or neglect Before running your TRX Racing Engine look over this entire manual and TRX RACING examine it carefully If for some reason you decide a TRX Racing Engine is not what you ENGINE ILLUSTRATED wanted do not continue any further Your hobby dealer absolutely cannot accept a TRX Racing Engine for return or exchange after it has been run INTRODUCTION TERMS TO KNOW Warnings hints and cross references THE FUEL Throughout this manual you ll notice warnings and helpful hints identified by the icons THE AIR FILTER below Be sure to read them m THE GARBURETOR f An important warning about personal safety or avoiding damage to your TRX Racing Engine and related components BREAKING IN YOUR O TRX RACING ENGINE Special advice from Traxxas to make things easier and more fun TUNING THE TRX RACING ENGINE FOR Refers you to a page with a related topic TROUBLESHOOTING Support Your TRX RACING If you have any questions about your TRX Racing Engine or its operation call the Traxxas ENGINE Technical Support line toll free at 1 888 TRAXXAS 1 888 872 9927 MAINTAINING AND Technical support is available Monday through Friday from 8 30am to 9 00pm Central time STORING YOUR TRX Technical assistance is also available at www Traxxas com You
42. ocess up to a point Engines are generally optimized to use a range of nitro content for the best power O ring Rubber O shaped ring used as a sealing gasket Pipe Abbreviation for the tuned exhaust pipe on a nitro engine See Tuned Pipe Piston The piston is the internal engine part that is attached to the upper end of the connecting rod and moves up and down in TRX ENGINES 9 TERMS TO KNOW TRX ENGINES 10 the cylinder sleeve The precise fit between the piston and the sleeve creates a seal that allows the engine to have the required compression for combustion Port Ports are openings in the sleeve that allow atomized fuel to enter the combustion chamber and burned exhaust gases to exit The shape and location of the ports are a large factor in controlling the engine timing and power output Priming Manually causing fuel to move from the fuel tank up to the carburetor This is sometimes necessary after the engine has been sitting for a long period of time and all of the fuel has drained back to the tank On a Traxxas model this is done by holding your finger over the exhaust tip for one or two seconds while the engine is starting Punch A term that refers to how quickly the model responds to throttle input or how quickly it accelerates Rich A running condition where the engine is getting too much fuel for the available air It is better to run an engine slightly rich to increase engine life Exc
43. one thousand one one thousand two one thousand three and then stop Repeat this starting and stopping procedure until the fourth tank of fuel is nearly empty 2 Apply the throttle gradually Your finger should not reach full throttle until the end of the three second count 3 Keep your driving smooth and consistent 4 When the fuel tank is nearly empty shut off the engine and refuel 1 Driving procedure Gently pull the throttle trigger to full throttle over a 3 second count hold for 2 more seconds and then gently apply the brake to stop Count the five seconds out while accelerating Repeat this starting and stopping procedure until the fifth tank of fuel is nearly empty 2 The model should now be shifting into second gear If it is not try turning the high speed needle clockwise 1 8 turn to lean the fuel mixture slightly and test for shifting 3 When the fuel tank is nearly empty shut off the engine and refuel BREAKING IN THE TRX RACING ENGINE P Clean your air filter before you proceed Refer to the instructions on page 14 During the High Altitude Operation sixth tank of fuel the engine can be tuned for general performance use Proceed to the next If you live a high section in this manual for instruction on tuning the engine altitude region 5000 or S more feet above sea level 1 1 4 2 Seconds 15 Minutes Off Apply throttle gradually the lower air density may l require you to lean your 2 1 2 2 Second
44. oplets in the air and also controls the air fuel ratio of the mixture entering the engine how much air for a given amount of fuel To help provide a better understanding of engine tuning and why it s necessary the following is a brief explanation of the air fuel combustion process that takes place inside the engine In order to create the cylinder pressure that results in power the engine burns the air fuel mixture Both air and fuel in correct amounts are needed for proper combustion It is the carburetor s job to mix the air and fuel together atomize the fuel in the correct proportion for the best possible combustion This is the ideal air fuel ratio required for the engine The ideal air fuel ratio remains roughly constant Due to variations in atmospheric conditions temperature humidity altitude etc fuel flow adjustment valves called fuel mixture needles are required to meter the fuel and maintain the ideal air fuel ratio in these ever changing conditions For example colder air is more dense more air molecules for a given volume of air and therefore requires more fuel more fuel molecules to maintain the correct air fuel ratio Warmer air is less dense fewer air molecules and therefore needs less fuel to maintain the correct air fuel ratio The tuning needles are there to adjust how much fuel is made available for the carburetor to mix with the available air atomization Warm Air less dense Co
45. otating the starter shaft as pressure is applied towards the crankshaft Once the starter shaft is keyed into the crank pin join the backplate to the engine case and secure the assembly with the four 3x6CS screws 1102 On non starter models simply align the reliefs in the backplate and fasten it to the crankcase with 4 3x6BCS screws Install a new glow plug Traxxas 3232 is recommended for your TRX Racing Engine into the cooling head The engine is now rebuilt and ready for the installation of the clutch assembly and the EZ Start system if so equipped 1 2 Slide the split cone washer over the pilot shaft with the larger end of the taper toward the engine case 1201 Slide the flywheel over the pilot shaft and onto the split cone washer The split cone washer should fit inside of the tapered hole in the flywheel Thread the flywheel nut all the way up to the flywheel and tighten the flywheel to 55 65 inslbs of torque against the flywheel 1202 1 3 Slide the clutch shoes onto the flywheel Key the flywheel pins into the holes of the clutch shoes See picture 1301 for orientation of the clutch shoes Tip By reversing the direction of the clutch shoes the clutch shoes will provide a little firmer bite against the interior wall of the clutch bell This is useful on higher bite surfaces that offer a higher level of traction 1 4 Clean and lube both clutch bell bearings and install a ball bearing into
46. pensing bottle may look like a cool drink t toa child Racing Engines are not intended for use by children under 16 years of age without the supervision of a responsible and Model engine fuel is flammable Never allow smoking sparks heat or flame in the presence of fuel or fuel vapors The engine and exhaust system may become extremely hot during use Be careful not to touch the parts especially when refueling or stopping the engine Prolonged exposure to the engine exhaust can be harmful Avoid breathing the engine exhaust Always run your TRX Racing Engine outdoors in a well ventilated area Never run the engine indoors Do not operate your model at night or anytime your line of sight to the model may be obstructed or impaired in any way Never operate your model in crowds of people or busy pedestrian areas TRX Racing Engines make models very fast and could cause injury to those unaware of its presence Because your model is controlled by radio it is subject to radio interference from many sources beyond your control Since radio interference can cause momentary loss of control always allow a safety margin in all directions around your model to prevent collisions The engine can be loud If the noise makes you uncomfortable wear ear protection Be considerate of your neighbors by not running your model early in the morning or late in the evening Most importantly use good common sense
47. plugs to require periodic replacement Only use Traxxas heavy duty long glow plugs Check to make sure the fuel is getting to the carburetor Remove the fuel line where it connects to the carburetor to see if there is fuel in it If not you may need to prime the engine Reconnect the fuel line and then refer to page 20 for instructions on priming the engine Check your fuel mixture settings It may be necessary to adjust the fuel mixture if the outside temperature or barometric pressure has changed significantly since the last time the engine was run see Fine Tuning the Carburetor on page 27 Turn the high speed needle out rich counterclockwise 1 4 turn hold the throttle trigger at about 1 2 throttle and try again to start the engine Once started retune the engine for performance see page 24 TRX ENGINES e 29 TROUBLESHOOTING THE TRX RACING ENGINE The engine could be worn If the fit between the piston and sleeve is loose compression is reduced and the engine will be difficult to start when it is warm and may tend to stall when running and when the throttle is closed suddenly to idle Engine life depends on many factors including fuel type air filter maintenance needle settings and how the engine was used For example if the engine was allowed to ingest dirt from lack of air filter maintenance or running through water then the internal engine components could wear out extremely fast Glow plug may have failed If using an EZ S
48. rect fuel in your TRX Racing Engine for maximum performance and engine life Traxxas Top Fuel should be used to ensure correct engine lubrication performance and ease of tuning Traxxas Top Fuel has been proven in thousands of engines so you can count on it every day for great performance A DANGER Model engine fuel is poisonous to humans and animals Drinking the fuel can cause blindness and death Handle with care and respect Keep it out of reach of small children at all times While driving do not leave your fuel dispensing bottle on the ground where a child Traxxas Top Fuel is made with just the right balance of the highest grade natural and could have access to it synthetic lubricants to allow excellent throttle response and the best top end Follow fuel label warnings performance without sacrificing long term durability Top Fuel is the only fuel which is 100 certified for use in Traxxas engines All of the components in the fuel are carefully selected from the best materials available and then custom blended to match the metallurgy and temperature characteristics of Traxxas engines You may use 10 20 or 33 nitro content fuel Try to use the same percentage all the time avoid switching back and forth between fuels We recommend that if you break in your engine on 20 fuel that you stick with that percentage If you do move to a higher or lower percentage make sure you readjust your fuel mixture to compensate
49. s 15 Minutes Apply throttle gradually high speed fuel mixture 3 1 2 3 Seconds On Reduce idle speed if necessary slightly from the factory 4 Full 3 Seconds On Gradually accelerate over 3 second count break in settings Try this 5 Full 5 Seconds On Accelerate over 3 second count if you are experiencing hold for 2 seconds difficult starting or m extremely sluggish Winter Break in Tips engine performance at During the break in process the piston and sleeve wear into each other to form a precise fit The high altitude engine needs to heat up to a temperature of at least 200 to 215 degrees to allow the piston and sleeve to achieve this fit properly A precise fit between these two components is critical for proper compression and optimum performance If the engine runs too cold during break in the piston and sleeve will not expand to their appropriate sizes for break in This can lead to premature wear of these components This wear may not become apparent until winter has passed and the engine is operated under warmer running conditions Warm the engine to approximately room temperature by removing all fuel and storing the vehicle inside at room temperature until just before starting the engine An extremely cold engine can become difficult to start After the engine is running it is important to keep the temperature of the engine to at least 200 to 215 degrees during break in In weather below 45 degrees your TRX Racing Engine
50. sly After each hour of running Clean and re oil the air filter The instructions for this procedure are on page 14 We cannot stress enough the value of cleaning your air filter at the scheduled intervals The cleanliness and condition of your air filter directly influences the running life span of your engine i ir fil Clean the outside of the engine of accumulated dirt oil and grime Accumulated grime will decrease the engine s ability to cool itself After each running session Perform after run maintenance on the engine Seale is engine of destructive moisture and other corrosive deposits This is ly i r the life of the engine See page 34 for after run maintenance procedures Inspect the vehicle for obvious damage or wear Look for 1 Loose or missing screws 2 Cracked bent or damaged parts 3 Cut or loose wiring 4 Cut or kinked fuel lines 5 Signs of fuel leakage Inspect the gears for wear broken teeth or debris lodged between the teeth If the engine is worn or damaged enough to require replacing the piston sleeve or connecting rod consider exchanging your old engine for a brand new engine under the terms of the Traxxas Lifetime Engine Replacement Plan ERP It could save you time and effort Details are in your documentation package or on Traxxas com Don t put the fuel from your tank back into your fuel jug Dispose of it properly following city or county regulations
51. tart check to see if the glow plug light is on when starting If not replace the glow plug If using a glow ignitor remove and check the glow plug Engine performance sluggish Engine performance depends mostly on the fuel mixture settings and how they compensate for the current atmospheric conditions Before you suspect other failures with the engine richen the high speed needle at least 1 4 turn and then retune the engine for performance see page 24 Try a new Traxxas glow plug Sometimes a glow plug will work well enough to start the engine but not be able to deliver the engine s full performance potential If the fuel mixture seems to be set correctly make sure the fuel is fresh If the fuel is old or was left uncapped for a long period then some of the important fuel components could have evaporated Try new fresh Traxxas Top Fuel e Check to make sure there is no binding in the driveline that would cause excessive loads on the engine Engine will not spin pull start or electric starter will not turn the engine The engine could be flooded If too much fuel accumulates in the combustion chamber at start up the engine will hydraulically lock Follow the procedure on page 31 for clearing a flooded engine Check for binding at the engine flywheel If you are not able to turn the engine by hand the engine could be flooded there could be binding in the clutch system or there could be internal engine damage See page 31
52. tarter handle continuously for g Do not store your model 9 about 10 seconds Remove the rag or paper towel and repeat steps 5 7 two more times Clean and re oil the air filter so it will be ready for use next time See page 14 for air filter maintenance instructions 10 Replace the glow plug and reinstall the air filter Other periodic maintenance Piston sleeve The life of the piston and sleeve will vary greatly with how the engine was used and maintained The piston and sleeve should be replaced when they no longer seal effectively loss of compression Symptoms include the engine being difficult to start when warm stalling when warm and stalling when throttle is suddenly closed to idle Replace the wrist pin and G clip whenever the piston and sleeve are replaced Follow the instructions for the proper break in procedure of a new TRX Racing Engine whenever the piston and sleeve are replaced Connecting rod The connecting rod should be replaced when the piston and sleeve are replaced or after three gallons of fuel whichever comes first Also replace the piston wrist pin and G clip whenever the connecting rod is replaced As with other internal engine components the connecting rod s life depends on the engine s usage and the quality and frequency of the engine s maintenance indoors with fuel remaining in the tank or the engine TRX engines are designed to be easily rebuilt Critical engine components such as the crankcas
53. the air filter to gain access to the idle adjustment screw 3 Turn the screw counterclockwise to reduce the idle speed or clockwise to increase it L The idle speed should be set as low as possible while still maintaining reliable Higher nitro requires a running characteristics richer fuel mixture When 4 Reset the throttle trim on the transmitter to its original position running 33 fuel richen your high speed needle 3 4 turn if previously running 20 nitro and then re tune the engine for maximum performance Fine Tuning the Carburetor After fine tuning your TRX Racing Engine at the end of the break in procedure no major adjustments to the fuel mixture are usually necessary Make note of the temperature humidity and barometric pressure at the time you finished fine tuning your carburetor Current weather conditions can be found online from national websites local TV news websites and television This information will be considered your baseline setting You may need to adjust your carburetor needles to compensate for changes in temperature and barometric pressure air density from day to day Generally you ll need to richen the fuel mixture when the weather is colder than your baseline temperature and the air density is higher Lean the fuel mixture when weather is warmer than your baseline temperature and the air density is lower The chart below provides general guidelines on how weather conditions affect air density when they move
54. the most influence on engine temperature is air temperature Expect the engine temperature to vary almost in direct proportion to air temperature Assuming you tuned the engine for the same maximum performance each day the engine will run about twenty degrees hotter when it s ninety degrees outside than it would in seventy degree weather For this reason we cannot give you a definitive temperature range that indicates the best possible engine tuning The temperature gauge can aid you in tuning by giving you a relative indication of how your adjustments are affecting the engine and to help prevent you from reaching excessive engine temperatures For example as you lean the fuel mixture the engine performance will increase along with the temperature If you continue to lean the fuel mixture and the temperature increases but the engine performance does not change then you have exceeded the maximum safe lean setting Make note of the engine temperature Generally try to keep your engine from exceeding 270 F when measured at the glow plug If necessary increase airflow to the engine by cutting out the rear of the body windshield and front valance In some situations the engine may perform very well with no stalling lagging or hesitation at temperatures above 270 F particularly in very hot climates If richening the fuel mixture to bring the temperature down to 270 F results in poor sluggish performance engine never cleans out then return the
55. ton sleeve and connecting rod it may be best to take advantage of the Traxxas Engine Replacement Program ERP B Use after run oil to lubricate the bearing surfaces of the crankshaft before assembling it into the crankcase Slide the crankshaft back through the crank bearings until it stops Inspect the carburetor O rings for damage and the rubber throttle arm boot for tears 801 amp 802 Unscrew the hi speed needle all the way out of the needle housing 803 and flush out the hi speed needle housing and the carburetor body with denatured alcohol or electric motor spray Use compressed air to dry the components Remember Always wear safety glasses when using compressed air to prevent injury Reinstall the hi speed needle into the needle housing and return the mixture setting back to the factory recommended break in setting 4 turns out from fully closed Carefully insert the carburetor into the crankcase until fully seated While pressing the carburetor firmly into the crankcase tighten the pinch bolt 804 This process ensures that the upper O ring forms a good seal between the carburetor and the crankcase 9 Apply a drop of after run oil in the piston s wrist pin bore before installing the wrist pin Locate the oil hole refer to pic 901 in the connecting rod and the skirt relief side of the new piston Insert the connecting rod into the piston with the piston skirt relief and the oil hole on the same side
56. used for off road motorcycle and ATV engines This type of filter oil is available at motorcycle pro shops Apply 30 drops of the Traxxas filter oil evenly to the top bottom and sides of the filter element 30 total drops divided among the 3 surfaces Squeeze the filter element repeatedly to help spread the oil throughout The filter element should be evenly colored by the oil Even color indicates that the oil is distributed evenly Do not squeeze out excess oil Note Do not use the air filter oil for anything other than the air filter It is not meant to be a lubricant 6 Reassemble the filter and install it on the engine making sure the rubber filter neck fits securely on the carburetor with no gaps or air leaks TRX ENGINES 15 THE CARBURETOR Factory Needle Settings If your factory preset carburetor adjustments have been tampered with use the following settings Set the high speed needle to 4 turns out from closed Set the low speed needle so the screw head red in Fig A is flush even with the end of the slide yellow in Fig A Needle Adjustment Always use the factory settings for initial starting Only use these settings when the factory settings have been lost TRX ENGINES e 16 Understanding the carburetor adjustments The carburetor performs several functions It controls the engine s speed by restricting the intake of air and fuel into the engine It atomizes the fuel suspends the fuel dr
57. well ventilated area Your TRX Racing Engine doesn t usually require priming If you do need to prime your engine watch the fuel line carefully to avoid flooding your engine See page 31 for information on clearing a flooded engine O Your carburetor is pre set at the factory to give the correct air to fuel ratio and idle speed for engine break in Do not adjust the carburetor unless you observe a poor running condition that requires correction TRX ENGINES 19 BREAKING IN THE TRX RACING ENGINE Important points to remember during break in Special break in fuels are not recommended Use the same fuel you plan to use everyday If possible avoid breaking in the engine on extremely hot or cold days Pay careful attention to the fuel level Do not allow the fuel tank to run completely empty An extremely low fuel level causes the mixture to run too lean This could result in a burned glow plug or extremely high engine temperatures Do not attempt to break in your TRX Racing Engine by idling it on a stand This will produce poor results Keep extra Traxxas glow plugs handy The break in process can cause deposits to form on the plug leading to plug failure Change or clean your air filter after break in Follow the instructions exactly for each of the first 5 tanks of fuel See Safety Precautions on page 4 for other precautions Starting Your TRX Racing Engine for the First Time Before you start your TRX Raci
58. will tend to run at lower temperatures between 160 to 180 degrees when tuned at proper break in mixture settings This is too cool for break in Do not lean the engine to increase engine temperature This will also decrease lubrication and cause your piston sleeve to wear prematurely TRX ENGINES Z3 BREAKING IN THE TRX RACING ENGINE Wrap the cooling head with a paper towel clean rag or sock to help keep the engine running at the recommended 200 to 215 break in temp If too much heat is contained the engine may run too hot Make sure that you monitor the engine s temp closely for the first couple of tanks until you get the right amount of cover for the cooling head This will of course depend on your current weather conditions Adjusting the cover up and down exposing more or fewer cooling fins is a convenient way to regulate engine temps For owners that do not have access to a temperature probe a drop of water on the cooling head around the glow plug area should slowly sizzle for approximately 6 to 8 seconds when the engine temp is 200 to 210 degrees If the water sizzles for only a few seconds then it is likely that the engine temp is over 220 degrees and needs to cool down If the water takes a long time or does not evaporate at all then the engine is too cool We do not recommend that you operate your engine below 35 degrees Fahrenheit If you insist on running your vehicle below 35 degrees be aware that nitro engines m
59. y removing the two 3x15CS screws 102 amp 103 If your engine is equipped with a starterless backplate proceed to step 2 Remove the three 3x12BCS screws that secure the EZ Start or pull start assembly to the engine and separate the drive unit from the engine 104 Be sure to remove the 6x8x0 5 Teflon washer that is installed on the starter shaft between the one way bearing and the engine Pye 2 Remove the 5 0mm E clip from the crankshaft Nitro 4 Tec owners will need to remove the 3x10CS screw and slide the 5x8x0 5TW with the clutch bell off of the crankshaft Nitro 4 Tec owners will need to slide two 5x8x0 5TW off the pilot shaft Caution It S important to use eye protection when removing the E clip from the shaft to prevent the clip from causing an injury Pull the clutch shoes off of the flywheel pins Remove the flywheel nut from the crankshaft using an 8mm socket 202 and disconnect the flywheel from the crankshaft by lightly tapping the back of the flywheel with a rubber or plastic mallet Place a small flat blade screwdriver into the slot of the split cone washer and twist slightly to loosen the split cone from the crankshaft 203 Slide the split cone washer off of the crankshaft The engine is now ready to be rebuilt 204 3 Remove the glow plug from the cooling head and discard the plug The glow plug should be replaced with a new one anytime the engine is rebuilt Remove t

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