I'm sure this topic has been beaten to death but I have a question on the proper jetting for my '86 LT
I bought a carb rebuild kit and it came with a 190 main.
Currently it's running a 220 I believe with an FMF exhaust, mixture screw is 1 turn out, main needle is 3 positions down from the top. It has trouble coming back down to idle if I whack the throttle.

.I have to run a stock exhaust for the race class I wanna run. What main should I run with a stock exhaust? The airbox lid is gone.

Thanks

If it ain't wanting to idle down, sounds lean, or like the slide is gummed up. I'm guessing since you know the jet sizes, you've cleaned the carb right? Even with rich enough jetting, if your float Height is off even 1mm, she can lean out on ya. And that's hard on er.
I'd be glad to tell ya my formula, but I got a different motor, carb and all than u
Hopefully someone with an 85-86 can hook u up