Engine Sync... 1986 5.7 L

[swellraiser]

I can't seem to find anything on the engine sync for a 1986 5.7 Mercruiser (2) . I just bought the boat less than 6 months ago and last outing was not very pleasant.

After working my way planing the boat & catching some seaweed, then clearing the sea weed - my Starboard side Rochester Quad Jet decided to hiss back at me. And the evidence of a lack of power was beyond obvious - I had to crawl at a 4knot pace back to the docks. The engine sync at this time was not happening to well at this time either...

Pulling the spark plugs my discovery was only 4 cylinders were firing - pointing again to the carb. So I rebuilt the Carb, and installed...but the engine sync needle seems very bouncy, I never noticed this before. This is while still at dock in neutral not under any kind of load - even pushing to 2K RPMs the needle seems still more eratic then before all this happend....any clues?

 

[sandkicker]

Re: Engine Sync...

Engine sync info usually comes from the ignition system. For me, failure of 4 cylinders to fire points at the ignition. Sync needle bouncing also says... erratic ignition.

Also... if gas sat around for awhile, then the ethanol gremlin got you.

 

[swellraiser]

Re: Engine Sync...

Engine starts without a hitch and can idle and run all day long - not backfiring, Ignition system...okay so that means coil, wires, distributor cap, anything else and where does the engine sync tie into the engine?

Gas is fresh or mixed with fresh...I've been using the boat at least once or twice a month during the winter months...I am in California

Thanks for the input...