nitroman99

I have a tmaxx with the new 2.5 motor,i have had no problems with the truck other than alittle wear and tear. i bought the truck used and it ran pretty good but when it would get up to a good running temp(240f) it would not idle for anything, it put out all kinds of power but wouldn't idle so i decided to rebuild the motor, new piston/sleeve, gaskets, new carb body because i stripped out the old one, and made sure everything was locktighted down with even torque. the engine break in went good but after the break in it is doing the same thing, when it gets up to temp it dies. also i am using duratraxas redalert 20% fuel. i have rechecked the backplate gasket, the head gasket, put a new glowplug in, new fuel lines, and rechecked the new sleeve to make sure somehow i didn't burn it up and everything looked great. i read a post on someone saying that the clutch spring and bellhouse bearings could cause this kind of problem if they are wore because they could drag the motor down, also the crank bearing are in good shape also(the outer bell bearing looked like it had been spinning inside the bell but i was unsure if that was enough to pull the engine down.). i am lost, i have rebuilt many motors, gone and helped newbies with tuning their engines so they don't burn them up and i have called the tech line and they are no help all they say is "it sounds like a tunning problem," i know how to tune a stupid motor. i usually don't get stumped this bad but i figured that someone out their has had the same problem and would lend me some advise. Thanks again.

rozzibandit

My Feedback: (1)

The 2.5R motor on Revo does the same thing. I also have been tuning nitro motors forever, mostly helis. But this idle prob with this motor has gotten the best of me so far. I got sick of messing with it and just turn up my throttle trim a hair. That is the only way I am garanteed it will stay running. Otherwise the motor is a powerhouse and runs flawelessly

nitroman99

Thanks for the info, is their a carb that i can switch out to somehow fix this problem, because as i have read also of people are having the same problem.

fhm101

Pull your carb apart and check for cracks and warped parts. if all is in order, put it back together with fresh o rings and seals and it should work OK. On the big plugs that cover the access holes, put a dab of silicone seal on the o rings before you put the plugs back in. if you are still having problems, there are 2 OS carbs that are a direct fit replacement for the 2.5. The 10D which is found on the now discontinued big block 15 RX, but should still be available, and the 10J which is found on the 12TR. Either carb will drop right in and should solve all your tuning issues with the 2.5.

SexyPizzaMan

My Feedback: (19)

hmm, thats strainge. During the end of break in my revo was idling pooly andwould cut somtimes, i just tuned the idle and now it runs fine. Not a problem. purrs liek a kitten

rozzibandit

My Feedback: (1)

LOL , oh yeah. The motor HAS to be broken before it will run decent. It will get better, about a gallon and it really runs nice. At least that was my engine.

SexyPizzaMan

My Feedback: (19)

Also clean out the header and muffler every so often. My revo wouldent even turn on because so much oil built up in the muffler and header and was oozing backint the engine. The engine seems fine but not as powerfull as i would have like in grass. I will be getting trinity siro 3.0 .18 tmaxx engine soon. I just have to find out if it will mount using the existing revo engine mount.

nitroman99

well i took the engine apart to check everything out, everything looked great, the block bearings looked great very smooth and no discoloration, seals were in good shape, piston and sleeve looked good but as i was reinstalling the back plate i stripped out one of the threads on the back plate, and if that didn't make me furious i was cleaning out the carb body that was new and went to reinstall the plugs and saw that the new carb body had already been stripped out again, the bad thing about all of this is i still don't know what is the problem, i have replaced the clutchbell, bearings, and clutch and spring thinking that maybe that it was rubbing and causing the engine not to idle, i also checked the oneway bearing, everything looked great. I don't give up to easy but i think this one got me, I can spend another $50 on a block and carb body or just eat it and get a fantom fr18 that has 1.9hp and has great reviews for being reliable and very powerful and also easy to tune. Hopefully i will make the right decision.Thanks

fhm101

The Fantom is a very nice engine, but why not wait a while and get the new rear exhaust .18 from OS? If it's anthing like it's side port borther it will be as fast as the Fantom with way more torque.