puzzleboy

Boat ran great all weekend. Yesterday, after being moored all day in one of our favourite party bays, I go to start and nothing- no solenoid clicks or anything. So I figure maybe the battery's down (radio all day, etc.). Switch to BOTH, and it fired right up.

Then after an hour of hard running (racing a buddy), same thing, only this time, no avail. So I get towed for a half hour or so, and my buddy turns the key at this point, and she fires right up.

Any thoughts? Maybe the Neutral SS (I did jiggle the lever around at the time), key switch, kill switch, cable corrosion? Slave solenoid was done last year. Had it not been dark, I probably would have tried jumping the starter solenoid, slave solenoid, etc.

Nightlife1970

Check the ground on the block. Have had 2 boats do that exact same thing, always ended up being the ground on the block. Just check all power connections even if they look good, they can build a corrosion film that will cause that.

250 sport

Is it charging back properly?

puzzleboy

Will do, and will check/clean all the other cables and connections. Maybe put some dielectric in between everything also.

I think she's charging well, gonna check the batteries. Probably have to remove them anyway to do the electrical cleanup.

puzzleboy

So, went out to the boat after work tonight, turned the key and.... Nothing (which was actually a good thing to see in terms of replicating the problem)

Turned the key a second time, and she cranked over right away. Batteris checked at 12.65 volts, not bad.

So I took apart the positive cables connected at the junction block mounted to the stringer. They were probably 50/50, so sanded them till everything was shiny. Did the same for the negative post on the back of the engine (that was fun to access). It was a bit cleaner though, which makes sense. Reassembled everything with Dielectric grease. Cleaned the battery terminals too.

Started 10 times in a row (stopped in between to cool the starter) with no issues.

I'll try again tomorrow, and I think I'll clean them at the starter also while I've got the battery trays out.

Hopefully this cures the issue!

Steel Outlawed

I bet you have the starter slave solenoid going bad. Mine went bad. On both engines about the same time. It is mounted on the back of the engine on the left side on the bracket that the wiring harness plug is attached to. It's on the back of the bracket so it's hard to see. But what you are discibing is exactly the way mine acted. It's a $30-$40 part.

puzzleboy

Did the slave last year (took apart and cleaned, quite easy to do actually), so shouldn't be that already. Mine's actually inside the electrical box mounted atop the engine. If it does happen again though, I can easily jump the large terminals of the slave to rule it out or pinpoint the problem. Thx.