What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Spark Plug Condition

H

HDDAHL

Active Member
removed spark plugs today. Cylinder#'s 1 and 2 were black, not glossy, indicating rich mixture or cool operation. #'s 3 and 4 were a nice tan indicating proper air/fuel etc. I am at a loss to explain why the front two would be operating richer than the rear. Any ideas folks?

Doug Dahl
 
HI I have been told that rotax engines run very rich on two cyls at idle and the only way to properly check them is to fly at near full throttle for 30 minutes then cut the mags and land and then remove plugs and check them then
 
HDDAHL said:
removed spark plugs today. Cylinder#'s 1 and 2 were black, not glossy, indicating rich mixture or cool operation. #'s 3 and 4 were a nice tan indicating proper air/fuel etc. I am at a loss to explain why the front two would be operating richer than the rear. Any ideas folks?

Doug Dahl
Click to expand...

Not at all unusual for the 912, has to do with the air distribution in the manifold. See the same every year. Fly-on!
 
You must log in or register to reply here.
Back
Top