Idle goes up then down.

[NinoBrown]

I've been a nitro enthusiast for 10 years. I'm just your typical backyard basher and I rebuilt a few engines in the past. I run into problems where the idle goes HIGH after a run and it goes back down after a few seconds or more. I've been ignoring this problem for years but it starts to get annoying. I always make sure that there are no engine leaks but it sounds like it goes lean then goes back to normal. Especially if I do a quick rev it goes away.

 

[jerzey10]

What kind of engine are you using?

 

[hotrodrob]

back off the hsn a tad,after a wot pass the carb is still metering from the hsn,it takes a second or two for the lsn to catch up,..double check for an air leak can't hurt