odd temps and tuning

[brokeitagain]

Ok so I have a 2.5 smaxx with aftermarket cooling head and I sealed the engine right after I got the truck (was used and already had the head on it when I got it so I pulled it and checked everything all seemed well) as of yesterday I just started on my 5th gallon of odonnell 20 percent and here's the issues I'm having

1. Car seems to run way rich or way lean no in between its been runnin awesome. temps were 230 to 240 most times for last 4 gallons yesterday when I brought it out they were 310 peak after letting engine heat up and running two big circles I turn 1/8 turn hsn richer because it was much cooler then b4 temps dropped to 180 after passes and wouldn't shift so I bring up in one hour increment by one and temp jumps to 280 again after passes
2. Car refuses to shift unless temp is up in the 280 plus range and I've constantly had the issue of having to turn shift point back except on my last gallon of fuel it ran awesome all the time n shifted great now it winds out first then just holds there unless I'm going down hill or lean it up
3. Car has good thick smoke but is still hot as all get out but when I rich it up smoke goes away and car has no power at all and temps are at 200 to 210 tops if I turn the needle even a smidgeon higher they jump back to 280 after passes
4. When car finally does hit 2nd it shifts but will not go any faster just stays in low rpm range with no power
5. Last of all when u get it really lean to where its runnin well steady idle shifting fine (I got it to do this twice but it HAD to be over 290 degrees to do it) it would run awesome but when you let off to brake then punched it it would bog and have no power at all until it was back up to speed then it was like someone hit a switch and it takes off
6. Last of all you have to hold at wot for it to start motor feels like it has decent pinch but definitly not what it was but once it starts it runs fine most times but randomly shuts off if I let sit for a while and with it sitting idle temp will drop back to 235 to 240

That's about it sorry for the long post but trying to get in all the details cuz I've done hours of searching and can't figure it out my ideas were either that somethins up with my transmission (hence the constant need to readjust shift point) and it winding out first like that is way overworking the motor causing it to get that hot or two that maybe my gas tank seal is bad causing it to run way rich sitting but meaybe bouncing open in the grass causing lean, or my motors bad but I don't know signs of bad motor I just figured when its done it wouldn't run at all. Thanks again and if you need pics more details or anything lemme know I'm on all day and all advice is appreciated cuz its ticking me off bad at this point as its my baby and I run this thing almost every day

Oh one more note a lil while back (in the last half of gallon four) I added a fuel filter and a bunch of extra length onto the fuel send line ( about twleve inches more now) so if it flips it won't shut off before I get to it and I raised the suspension as high as it goes for off road use if any of that makes a difference also it suffered a bad flip last time I ran it I was an asphalt and it landed square on the engine head hard enough to rip apart the glow plug wire and send sparks flying wondering if that may have opened up an air leak somewhere or bent somethin thanks again

 

[Metalhead Matt]

Shorten the fuel line a little bit and make sure there are no air leaks. Start by checking the header, tank cap, make sure the head bolts are tight and that the hoses are good. Make sure the carb is sealed and nice and tight. If the back plate isn't sealed, I'd go ahead and do that as well. Use high temp, sensor safe rtv. Sealing a Traxxas engine is always the first step when it doesn't run right.

 

[brokeitagain]

I sealed it all with copper rtv from a link posted here a lil while back but I guess it could've gone bad any usual suspect that go first n what's best way to get the rtv off when I open it again? Thanks also is it usual for the shift point too need constant adjustment?

 

[brokeitagain]

Ok so I tested everything for air leaks this weekend and the only thing I can see is when I blow into it really hard I seem to get a slight bit of fuel on the clutch bell but its just enough to notice its not bubbling anywhere and I think its just comin out the front bearing seal is that ok cuz some posts say it can leak a lil also tank has no leaks and I still wanna know what's up with the constant need to adjust the shift point? Thanks again

 

[Metalhead Matt]

I just re-read your post. My first advice was off the mark. I must have been day dreaming or somethin'. Your engine is most likely worn out. I'd be ecstatic to have gotten 5 gallons through a trx mill. You obviously know what your doing. I'd have to say that it's either time for a rebuild or start shopping for the next mill. The symptoms you describe definitely sound like worn bearings and/or loose pinch. Also watch those pesky needles. I've had a couple of trx carbs that took to adjusting themselves. The o-rings shrunk over time and the needles would rattle back and forth. Both of them.

 

[brokeitagain]

Yea that's what I didn't wanna hear lol anyone gotta cheap p and s I can get but yea I got it running but to run n shift right i had to be lean it out into dangerous levels and I had to retighten the slipper all the way but it definitly feels like there's almost no pinch so I guess it is what it is I was surprised at 5 gallons too lol especially cuz I startted with two quarts before gettin a gallon and this is my first nitro ever and I traded a mini t for the used smaxx (who knows how prev owner treated it) so I guess I should be glad I got what I did outta it thanks agaiin guys