Intermittent no start

Paul,
Measure the actual voltage at the starter when you are cranking the engine over. How's the timing? Is the distributor retarding and advancing?

Paul,
That 6 is a pretty big voltage drop. See if you can get more volt readings back to the battery when it "clunks". Say in and out at the start relay (solenoid) and then at the battery itself. This will tell you where the voltage drop is. but I suspect the battery cables and or terminals. They may look good but are bad inside.

Your timing is set at 10 but is the distributor retarding back to 10 when the engine isn't running?

tryathlete wrote: Take the battery and have it load tested to make sure it does not have a bad cell. Swapping parts between boats is creative. Why not swap batteries?

Had one in my truck just in case but when all the voltages were in check and it would crank and start with no issue half the time I didn't feel it's battery related.

I think the next time we work on it I will bypass the battery cables by using jumper cables and see if that makes a difference.
I still haven't ruled out grounds/dash wiring.

Battery cables or connections, id bet money on it.

I just swapped out my positive cable terminal for a non-start issue. When not under load I had 14 at battery, 14 at solenoid and ground. Turn key, pop sound near back engine fuse, ignition circuit went dead, and then nothing, no bilge, no lights, etc. 30 seconds later, ignition circuit light would slowly come back on and I would have 14 again everywhere. Couldn't test voltage under load because once the key turned it all when totally dead.

Terminal and cable looked pretty good. Put jump starter on top of post and it would turn over, so I knew it was battery or terminals or wires.

I cut an inch off the wire before putting on the new terminals. Damn things are brittle and oxidized. I plan to replace them after this season.   

Here is another place too.

Can someone post the drawing that I believe Tim did with the basic wiring,I had it saved but my computer at work crashed and I lost it,
I'm at work now and would like to print it.
Thanks

Thanks Ken

Ha! Great news. I went through an ignition switch during the shakeout of the SS a few years ago. Love to hear of the successes this group produces. It sure makes ownership a lot more of a club than a solo act!