joelgould111

ok heres the deal i bought a new style t-maxx 3.3 and made it a full ally basher (check my other post)

i have had problems with overheating i belived it to be because of a real tight pinch


but now ive noticed that when the engine is hot -warm it has verry little pinch /compression

im worried now because it runs at 250f at 5 turns out

what could be the problem theres no air leeks

DaveG55

How do you know there are no air leaks? I ask because those certainly sound like classic symptoms of an air leak somewhere.

t-maxxmaniac

yep sounds like air leak symptoms....also if its all alloy...its heavy and that much weight for a 3.3 might make it runn hot

joelgould111

ive had a quick check for air leeks and there are no obious ones

i am going to change my spur gear to a 54 tooth one will that hellp at all

newgst

250f doesn't seem like a bad temperature...these things easily run at 270f. You should lose some pinch at higher temps because the heat expands the metal.
As far as sealing the motor have you done it yet? Seriously, if you havn't, You must seal these trx engines! You will really see a difference in tuning! Besides every trx motor i have seen had a leak by the pinch bolt.

edit: O btw if the alloy really made it much heavier than before you should try increasing the teeth on the spur gear

JB COMP

You have some kind of leak, you shouldn't even be running at 5 turns. (unless the 3.3 needs to run that much richer then the 2.5)

Seal the engine and carb. Check tank and fuel lines to make sure there are no holes. Check to make sure your head is on tight. I've had my head come loose on my 21 and it had low compression, but it would still run (and really good for have the head as loose as it was) I didn't see the leak (from the head being loose) either until I took it apart to mod it.

joelgould111

ok i have done a througher check of my whole engine and setup no leeks i even put the whole engine under watter and using a lng peice of fuel tube blew in the the the fuel nipple with my fingers over exhayst and carb hole not one bubble this is realy frustraiting now im scared to run my engine because if it blows up i cant buy another one

what else could be wrong

SPPaintball

that was probably a bad idea... make some use to wd40 to make sure it doesn't rust.

and seal the engine anyway. even if there's no leak when it's cold, keep in mind that at operating temp the metal expands.

joelgould111

lool no water got in lol fingers were protecting bt i but some aro in for good mesure

DaveG55

With the engine running at operating temps at idle, spray the backplate area, the front bearing area and the carb pinch bolt/carb base area with WD40 and listen carefully for any change in engine operation. If it speeds up or slows down at all you've found the leak. Also check the exhaust/ fue delevery system - the manifold screws tight?, the rubber coupler good/not torn, the fuel line has no holes, the pressure line has no holes, the fuel tank lid seals tight, etc. All those things can contribute to high temps.

NStampede Freak

What do you get on your pinch test? Your LSN could be too lean.

newgst

You know...maybe this sounds stupid but i figured out what my problem was. A piece of fuel tubing was crimped underneath the fuel tank and thats why i my motor would get lean after i started it. It started ok because i would pressurize the tank but once it was running normally the pressure from the exhaust wasn't enough to continue the flow of fuel through the kink!


i feel dumb[:@]

joelgould111

ok i did the swuirt test nothing just has a solid idle then i checked my fuel line and i have found that my fuel line is quiet tight so smaller diamiter i gona put some new longer fuel line on

lol should have checked that first

joelgould111

ok i did the swuirt test nothing just has a solid idle then i checked my fuel line and i have found that my fuel line is quiet tight so smaller diamiter i gona put some new longer fuel line on

lol should have checked that first

ChaosEngine

squirt test? just pinch the line, it should shut of in 3-4s

matts6887

Im with dave on this one. definitely sounds like a air leak somewhere indeed as a air leak can definitely cause overheating because of how the engine ends up leaning itself out...

joelgould111

nope definatley no airleek low speed shuts off after about 3 seconds im gona try new fuel line