Marinette Boat Forum

Trying to resurrect my 28 Fisherman. Changing plugs out I discovered the spark plug in cylinder #5 of the Starboard engine the end of the plug pushed in and has broken the porcelain. I fear the worst, spun bearing, broken and loose ring et cetera. Who has encountered this? When I place my finger over the plug hole and crank I still have pressure. I fear a rebuild or repower may be in need....Aaargh

FYI Here is a pic, albeit a bad one.

Better pics

Looks like someone dropped it or it is the wrong plug. Is it the same as the others? Have had stuff dropped down the carb that caused bad plugs. I would make sure it is the correct plug and put a new one in.

Does it rod knock?

Jeff

Ran it for a few minutes last fall to winterize but haven't had it up and running since. I hear a slight clunk when I turn it over but that may be coming from a bad tooth I have on the starter (replacement on the way).

Got my fingers crossed for you.

Jeff

Flexible bore scopes are pretty cheap now a days. There are also cameras with UBS plugs for a lap top. If a ring broke I think you would be able see a defect In the outer edge of the piston.

On second (or was it third?) thought, I'm hoping it got dropped and damaged before insertion. It happens. Also, I'm thinking the piston (with a wreck con rod bearing) couldn't come up far enough to smack it. Got my fingers crossed.

My buddy Harold once 'helped' me install plugs in my old Pontiac. Somehow he destroyed most of them in doing so and the poor thing would barely run.

Jeff