Itinerant Air-Cooled

Any idea the % CO change per turn on an AFM, not looking for super precise here, just an average. My AFM screw was one turn out from bottom and it blew a high CO idle number during a smog test.

There's no linear relationship. Plus, every engine's different.

When I bought my 78, 3 turns out gave 1.5% CO, 1 1/2 turns out gave 3.06%.

Now that I replaced all the intake gaskets and seals, I had to open it up 5 turns to get it to idle right.

jberger wrote:Any idea the % CO change per turn on an AFM, not looking for super precise here, just an average. My AFM screw was one turn out from bottom and it blew a high CO idle number during a smog test.

Depends on the setting of the black cog/clock spring.
Anybody home?
Colin