engine wont idle please help!

[jaymz383]

I just bought a used Tmaxx 2.5 and the engine was running to lean and the idle is way to high, so I put it back to the factory settings on the HSN, LSN and the idle. Well, it will idle right for a second and then it goes back to being real high. I can blip the throttle and it will go back to normal for a second but then it goes right back to high RPM's. I turned the idel screw all the way in and then out and the idle stays the same (high). I even tried turning the HSN and LSN and that didnt help any either. I have no idea what is wrong. Does anyone have any idea of what this could be?

Thanks,
Jamie

 

[Russ Winn]

Sounds like an air leak...check the carb seat on the crankcase. I'd try cleaning the mating surfaces where the carb fits in, and use a little permatex sealant around the base of the carb. Excess air being sucked in around the carb body could cause it to run lean.

 

[newnitrofan]

Umm this has nothing to do with tuning but if it is always going back to the same idle all the time you might check your radio trim and see if you can move the servo back a little bit!!!!

 

[jaymz383]

Thanks for the help! i'll give that a try.

 

[Krusty]

Jaymz,
Adjust the linkage so that it makes contact with the throttle stop screw at idle, the screw that actually determines the idle speed. You should have an "overide" spring installed in the linkage so this will happen. The carb barrel must "hit" the stop screw at the idle position. If this doesn't happen, the engine idle can not be adjusted correctly or idle consistantly (return to idle) and you will experience the problem you are having.