I have a 2000 Mercruiser MCM 4.3L carburated engine with a dieseling problem The dealer shop adjusted the timing when the problem first occurred. That fix only lasted for 3-4 times out on the water. I have since checked/adjusted the timing to no avail. Retarding helps but I lose power before the dieseling stops. I've checked spark plug condition and gap. Operating temp is ok-it hasn't changed since new. Idle speed per dash tach is ok. Idle mixture adjustment does not help. With some cool down time the engine does not diesel very often but the boat is used for stop & go water sports so it needs to shut down with the key every time. Anybody have some ideas please?<br />Fresno
