prophet1978

I got a T maxx with a 2.5R and its had about a gallon or so of fuel ran thru it since break in, and the last couple times that I've ran it, its been running strong for about five mins or so and then starts to bog and slowly bogs so much that there is almost nothing there for throttle, also starts to overheat after boggin. Now its never done this before, I clean the air cleaner air filter after every run and try to keep a strong glow plug in it. Plus I've never raced this motor. could this be a fuel mixture issue? cause I've tried to richen and lean the mixture to try to fix the problem. any suggestions?

Truck_Buster

iTrader: (64)

check for air leaks.

Duster_360

iTrader: (21)

Possible air leak, seal engine and see if ithat fixes things. If you've ever really tightened down on the carb bolt, trx composite carb bodies can crack easily. Whats frustrating is you need a magnifying glass to see the crack. When the throttle servo pulls the slide enough, that will open crack to leak enough air to mess up the tune, but will run at part throttle and idle fine. Can be hard to identify and hard top find.

Do you have any compression, both cold and hot? When cold engine can have some compression, but when gets hot and everything expands, there may be no compression. Time for new piston and sleeve or a pinch.

TRX engines are a little tricky to tune - make sure engine is up to op temp and change one needle at a time. Think clock face - adjust 1hr at a time. Run it long enough to understand what changed. If you're making big changes, you'll miss the sweet spot where it will run really well.

prophet1978

whats more hassle to fix, a front bearing or carb slide cause its narrowed down to one of the two, cause everthing else is tight and the leak has to be coming from somewhere in the front of the motor. I've been running it pretty hard lately trying to tune it just right for optimal performance and think I got the leak after a couple hard tumbles off some jumps. (see If I woulda had my roll cage on I could have avoided all this) by the way I'm trying to get this truck race ready do you guys know if theres any regs against having a roll bar or cage during racing?