Timing help needed

roccodart440 said

Ran it twice last week at the track. All seemed well, but still fat and unhappy at idle.

Contemplating trying out that smaller bushing and bumping the initial up before playing with the carb again.

Not to get off track but does everyone agree that if you are under 1.5 turns on the idle mix screws to go with .010 bigger bleeds and if you are over 2 to go .010 smaller?

Click to expand...

Don't get to concerned with the number of turns. The idle/transition circuit is a mini carb within the carb. The IAB and IFR work together to set the fuel ratio. The idle mixture screws meter how much of that air/fuel mixture goes to the idle passage. The only way to change that air fuel mixture to the transition slot is to install T-slot restrictors. Fix the timing first, then play with IFR IAB to get it right. I hope you are adjusting the idle mixture with the engine fully warmed up. If the motor idles when you first start it with no need to feather the throttle for a minute you are pig rich when warmed up.