I have been around gas engines many years, but my forte are diesel engines. Old school Detroits, Series 60’s and some Cummins.

My engines have been running poor;y according to me, so I tuned the starboard engine last week. Spark p.ugh came out gapped at .030, spec’s asked for .035. Distributor cap had center electrode worn right down, so I do not think the mechanic who replaced that engine 5 years ago did his job as he charged me for those parts. Distributor has ONE screw holding the cap dow. Replaced plugs (.035), wires with marine Mercruiser wires, OEM cap and rotor. She starts best ever, and runs smooth. I was going to wait until spring for the port, but figured while I was in there…..

Port engine was also a tough one to get at. Replaced spark plugs, (at least they came out gapped at .035!)cap and rotor came out looking good, but replaced with OEM too. Wires, the sweet wires…..this guy who did the work on this engine had them zip tied together, 4 of them, then 3, then 2…..the zip ties were SO tight the wires had grooves in teh, Non marine wires and I am sure there was some cross firing!. ANYWAY got the wires in the separators, clipped them in, and made sure there were 4 screws in teh distributor. Hit the key and it spun right to life, as it should. It used to start hard, and very hard when warm. People said it was because the engine had 1100 hours. However, compression was good to great. I am concluding that the wires tied together were the biggest problem, yes I used OEM Mercruiser wires. Now. onto the next project.