Carb and Manifold Cold

[Tom Wesenberg]

Originally Posted by Ron Lachniet

I noticed this fall that my two front spark plugs are always sooty and my rear two are clean. Could that be caused by warmer air in the back cylinders or is something else going on here. My engine was completely rebuilt this past spring and it just started doing this recently.

How does the exhaust look, both at startup and when warm? Do you see any white, blue, or black in the exhaust?

[Ron Lachniet]

The exhaust looks normal but it doesn't seem to idle as smooth and my oil is dirty within one hundred miles of an oil change so I know it is getting way too much carbon.

[MikeK]

A Burns manifold has a hot spot for improved street drive-ability, but if you are running headers, or have no connection to the exhaust it is useless.