I've heard people say to just back the mixture screws out until the motor smooths out and then stop. It seems when i follow this aprouch I only end up with the screws backed out about 2 turns. My plugs looked very tan with some white on the ground electrode. My questions are, before I start to fiddle with the mixture, what is the correct adjustment for the idle speed screw?, what is a good start point (ex. 3 turns out) for setting the mixture?


Rob

 

There is no "correct" adjustment with regard to turns out. The adjustment is there to allow you to set it to work right with your particular engine and setup.

The typical starting point is 1-1/2 turns out from full in. With the engine warm, idling in drive (park brake on and wheels chocked), all air cleaner and vacuum lines hooked up, turn the screws in equally (like 1/4 turn at a time) while watching vacuum gage. When vacuum drops, turn them out until vacuum maxes. Then turn them in 1/4 turn.

Some people leave them at the max vacuum reading point. The 1/4 turn in is more of an emissions thing, but will also help avoid fouling plugs during extended idle time.

 

Thanks bro..

 

Now if a person doesn't have a vacum gage, would going by the idle alone be good enough?

 

hey five7kid,

how much will the vacuum drop when you lean it out? Will it be a huge drop and very noticable or does it just go down a little bit?

 

It is hardly noticeable on a vacuum gauge.

 

It would be the best you can do.