HELP w/1995 40 horse Merc elpto

[jackstar]

I need help (my wife agrees)

Two years ago bought a boat with said motor. Garage stored in mint condition. Has run great with one issue.

Occasionally once out on the water after stopping and starting a few times, the starter will simply "whine" at turnover and not engage the flywheel. I have tapped on the starter and had a buddy help the flywheel up while starting and that seems to have solved the issue. All of this is on a fully charged new deep-cycle battery.

Yesterday, same thing. Fired up great the dock, ran a couple times, then came the starter whine for the fourth turnover on the water. Tried my old tricks plus reset the fuse in the line connected to the battery. Starter worked perfectly again several more times. However, after that I did get a beeping noise and my depth finder, which runs off that battery, cut on and off several times.

On the way back down river I stopped a last time. Went to start the motor again and got nothing, zippo...no whine, no nothing. tested the trim and the depth finder and they both ran just fine. The motor just would not turn over.

Is this a bad starter motor...solenoid...a blown fuse...or a short somewhere in the line. I think I rule out a short in the battery line because the trim function worked perfectly on the motor. I hate to replace a perfectly good starter motor if it's not necessary and I don't want to have to go to a marina if I can avoid it. I would imagine that won't be cheap. What can I do to diagnose and maybe fix this? Has anyone else experienced this sort of thing? The remarkable thing is most of the time the motor fires right up now problem. Except for the last attempt yesterday:facepalm:

Thank you all for any help you can give me!

JS

 

[CharlieB]

Re: HELP w/1995 40 horse Merc elpto

The starter drive is 'screwed' upwards on the shaft by inertia, the starter motor spins so quickly that the threads on the drive climb the shaft before the drive begins to actually turn.

A drive that does not rise can be caused by a dirty shaft, grease is not a good idea here, it tends to collect dust/dirt and create too much drag on the threads. Instead, a clean thread with no grease/oil, graphite or silicone based dry film lubricants work well.

The major cause of a 'slow' starter is poor connections, all battery and starter cable connections must be shiny clean bright and tight. The battery must be in good shape, charging system verified also as a low charge will not provide adequate current.

You can use a volt meter to check for voltage drop at each connection, especially across the starter relay, a poor connection in here cannot be seen or cleaned.

 

[Texasmark]

Re: HELP w/1995 40 horse Merc elpto

The starter drive is 'screwed' upwards on the shaft by inertia, the starter motor spins so quickly that the threads on the drive climb the shaft before the drive begins to actually turn.

A drive that does not rise can be caused by a dirty shaft, grease is not a good idea here, it tends to collect dust/dirt and create too much drag on the threads. Instead, a clean thread with no grease/oil, graphite or silicone based dry film lubricants work well.

The major cause of a 'slow' starter is poor connections, all battery and starter cable connections must be shiny clean bright and tight. The battery must be in good shape, charging system verified also as a low charge will not provide adequate current.

You can use a volt meter to check for voltage drop at each connection, especially across the starter relay, a poor connection in here cannot be seen or cleaned.

Ditto