Dave

Could the leak from the head shim look as if it was coming out of the carb?

Does this affect performance any?

At any rate, my first motor (from the first shipment I think) is a messy sucker No problems with power (16x13 APC at 8400 the other day, 30% nitro/3500'asl) or overall running, just messy.

Think that might be the culprit? I have never been too concerned since the motor ran so well. My other one doesnt seem to be as bad.