1st mercury I messed with. Cant get it to idle, runs fairly good above start position. Is it possible reed problems? Maybe jet to big? idle adjustment screw doesn’t change for me. Started at 1 1/2 turn went both ways. Just wont idle. Plugs are old champion K-3 with center pin ground electrode. Good blue spark
If it is really a KG7H it wasn’t designed to idle. It should have a full butterfly so it will stall at idle position. This was designed as a race motor.
gary
Hi, I’m with Gary on the possible answer. If the motor has a full butterfly that means the butterfly is one that is the exact shape of the throat of the carburetor and when closed seals off the intake air, thus the engine dies. Stock butterflies have a flat usually on the bottom side of the butterfly which lets in some air to mix with the idle mix fuel. Look inside the carb at the butterfly to see what you have.