No spark in 77 sea ray w/228 mercruiser.

[MichaelinAZ]

Hi guys, Im pretty much out of ideas as far as my friends boat Im helping him with. The boat sat for 10 years, and was in pretty good condition.
My friends and I went through it and did all the maintenance stuff, took it to the lake, and it ran like a top. Fast forward two weeks and now it doesnt start.
Its got power to the coil, and the coil sparks pretty strongly. Hook it up to the distributor and nothing. No spark coming out of the distributor. Replaced everything but the distributor housing, with no change.
Can it be some kind of electrical issue like some kind of safety device grounding out the distributor? There is power coming through the cap, but its not going to the spark plugs.
Any ideas?

 

[Bt Doctur]

There is power coming through the cap, but its not going to the spark plugs.

That makes no sense. If the coil is producing spark the dist must be turning. The spark goes into the dist cap on the center pin and the spark is distributed by the rotor to each individual lead inside the cap and out the spark plug wire.

 

[MichaelinAZ]

Yeah, thats exactly what I said. Makes no sense whatsoever.
Ive been working on small block chevy related stuff for 20 years and this is a new one to me.

 

[alldodge]

Sounds like the rotor is broke or missing

 

[thumpar]

It is a long shot but try disconnecting the tach wire from the coil.

 

[Bt Doctur]

If you mean the coil tower produces a spark when testing the coil and no spark comes from a plug wire then suspect the rotor is grounding out to the dist shaft.

 

[MichaelinAZ]

Well, after pulling half my hair out and reading thumpars advice, it was a twofold problem. The tach wire was loose, grounding out against the tach only partially. So it would intermittently work or not work as luck would have it. Took me the better part of the day, but I found it.
Definitely a new member!