Left Engine Running Rich

[George Kretschmann]

For some reason the left engine is always running rich. My mechanic is puzzled and I really don't know what needs to be done to correct the problem. Is there an adjustment to lean the overall range of mixture on a io 320 b1a besides the mixture controls. I believe the injectors are from another model engine. I do lean out but the bottom of the wing and inside the exhaust pipes are sooty. Thx. George

[N3322G]

George,

I know of at least two places to work on part of this. You should check the Service Manual first as I recall reading something there. Not enough of a mechanic to give more guidance than that.

[George Kretschmann]

[William Coleman]

There is a Lean/Rich adjustment on the right side of the fuel servo. With the right cowl removed and the engine running at idle adjust the thumb knob and look for a 50 to 75 rpm rise before it wants to quit. Of coarse this takes 2 people, one in the plane and the mechanic at the engine. You will also need to readjust the idle RPM.