The International Cessna^® 170 Association

Got one for you engine guys.
The o-300 in our 170 is showing two different colors of exhaust.Left bank is showing a slate grey color and right bank is soot black.I've been pickin brains around here and most think we have an intake leak on the left side allowing the right side to run rich. About ready to take it down for annual and figured I'd start rounding up the gaskets and intake hoes to see if that will fix the problem. Any thoughts??
Thanks,
Joe.........

The primer only feeds the pilot side. If either of your two 0-rings in the primer are leaking, that side will have a different exhaust stain.