engine acting irratic!!!!!!

[mwbmod74]

Hey guys great forum my question for you guys is i have a os rg21 thats got about 6 tanks threw it as rich as possible,but my problem is it runs great ,but after you get on the throttle it wants to high idle,I have made sure the servo is returning to idle,i have this thing slobbery rich on the low speed and the high speed needle,i have had the engine off checked to make sure there are no visible air leaks,everything is good and tight,when you throttle it and run the car its 4 stroking real good but as soon as you let off the gas it starts with this high idle crap, then bout 30 secs. go by and it will come down and want to die of course cause i have it soo soo rich on both needles....what the hell ?????Now my fuel is blue thunder which is about a year and a half old which has never been on concrete?????sooo wazzup ya think???? thanks for any replys

[coloradoNitro]

My guess would be that your idle gap is set alittle high. When you come off of wide open or close the slide isn't closing far enough, and it takes a few secs for the rich/slightly rich bottom end to get it to calm down. Alot of guys run w/ the bottom too rich, and set the idle too high to compensate. This also leads them to running w/the high end too lean to compensate for the rich bottom. This is 100% guess from what you said, but I'd look into the carb throat and see what kinka gaps there. You want it to be appox 1mm or the thickness of a matchbook cover.

[RobH]

Originally posted by mwbmod74
Now my fuel is blue thunder which is about a year and a half old which has never been on concrete?????

Even though you haven't had the fuel on the concrete, it may have deteriorated over the past year and a half. The other thing is that maybe the fuel has separated. Did you shake it pretty good before using it?

I’m thinking bad fuel. I’ve never heard of anyone running 1 1/2 year old fuel. If it’s not the fuel, it’s got to be a carb thing. I would go buy a brand new bottle of fuel and reset the carb back to factory defaults. Then, I’d retune it.

If that doesn’t help, then it’s time to start thinking internal problem (o-ring or a leak or something).

Good Luck,
Rob