351PCM - Weird Starter problem

[JRexrode]

Hello. I have a ski boat with a Ford engine (1994 351PCM).
It has a starting (starter) issue. Hopefully someone can offer some clues as to what's behind it. I'll list what I know so far:

- I have good power to the solenoid (12V).
- Turning key (ignition), I hear the solenoid click. no starter.
- I jump the connections at the solenoid, starter spins fine.
- I go back to the ignition, it turns over fine, as if no problem.
- I try the ignition again next time, solenoid only, again.
- I jump the solenoid again, starter still spins fine.
- Back the ignition, turns over fine.
- yet on next try, same deal, no starter....

I can repeat this over and over.
For some reason, if I spin the engine (socket on harmonic balancer) then the next ignition try usually gets a start. not always, sometimes takes a few tries. Once in a while, it does start fine... rarely. Mostly if it's been run recently. Not a flywheel issue, teeth are all good.

Something between the starter and solenoid?? Being a boat, moisture is around sometimes. But strange the repeatable sequence that gets it to go. No single component seems faulty, but together something is haywire.

Thanks for any clues!! Jim

[mechhound]

From what you explained I would be inclined to replace the solenoid.