Questions about Mercruiser 4.3 Litre LX

My first problem is I can't find the serial number anywhere... The plate is worn and the arrestor doesn't have it on it.

Anyway. I'm pretty sure I have an ignition coil problem, I removed it today and the primary coil (outside nuts marked + and -) shows a few hundred thousand ohms for a moment then goes to infinity. And it's full of water...

So as far as replacing one of these goes, is it a fairly generic part? Would any coil work or does it need to be a Mercruiser thunderbolt ignition coil for this model engine?

The plate says MCM 4.3 litre/lx - 205hp.
I found an alloy tag that reads MCM 205 3304-9354, and found two stamps one GM14096286, the other 14093683. No idea of the year yet, sorry I can't say much more about it than that. I found the transom and drive serial numbers which show up as 1988 models but not sure if engine year would be the same?

Is a generic coil from NAPA likely to work or do I need to order genuine Merc from somewhere?
Thanks in advance
Josh

Sounds like the primary has opened up....the factory coils work very well in the thunderbolt setups....and they should have the part number stenciled on the case....

makomark said:

Sounds like the primary has opened up....the factory coils work very well in the thunderbolt setups....and they should have the part number stenciled on the case....

Click to expand...

The primary coil was indeed open. New coil had it sparking right away. Re-configuring the ignition leads got it running sweat (whoever worked on it last 10 years ago put them on wrong) and a new fuel pump had it running consistently.

Going to do the bellows on it when the parts arrive as we have a transom leak as well.

Josh