1995 Mercruiser 3.0 starter will not engage flywheel

[Handgrenademike]

I have a 1995 Caravelle. Mercruiser 3.0. I replaced the starter because it seemed bad as it wouldn't turn over. Just clicked. New starter. No power at the key and when I bridge the solenoid with a screw driver it just spins but doesn't throw out the gear. Any help would be appreciated.

 

[alldodge]

Which starter did you buy?

 

[Handgrenademike]

Wilson brand from Oreillys. I opted to not go with the cheaper brand.

 

[alldodge]

Does the new starter do the same thing as the old one, just spin?

 

[poconojoe]

Is your battery up to the task? Maybe it's on it's way out and can't handle the amperage to fully engage the starter.
How are all your connections? Have you taken apart and cleaned all battery cable terminations, including the ground to the engine block?
Corroded connections can cause a lot of resistance.

 

[Handgrenademike]

Is your battery up to the task? Maybe it's on it's way out and can't handle the amperage to fully engage the starter.
How are all your connections? Have you taken apart and cleaned all battery cable terminations, including the ground to the engine block?
Corroded connections can cause a lot of resistance.

Cleaned everything already. Brand new battery.

 

[poconojoe]

Cleaned everything already. Brand new battery.

Oh well. I was hoping for an easy fix. Sometimes the obvious gets overlooked.
Good luck, hope you hash it all out soon and get boating.

 

[San_Diego_SeaRay]

Cleaned everything already. Brand new battery.

Oh well. I was hoping for an easy fix. Sometimes the obvious gets overlooked.
Good luck, hope you hash it all out soon and get boating.

Actually I once had an issue on my 7.4 where all the connections were fine. But amazingly rusty water had dripped from the manifolds (a separate issue) and it had run down in between the seams of where the starter bolted on to the block. Since the starter grounds itself via the block, that whole area had corrosion and prevented the starter from working.

For the OP, have you removed the starter and tried running it completely disconnected from the engine? Bench tested it? Watched for the gear to pop out to engage? I wouldn't run it for to long but just to verify it does work when off the engine.

 

[Handgrenademike]

I actually took the new one and had it tested after it didn't engage. It tested good.

 

[Scott Danforth]

clean every connection from the battery to the starter. by clean, use 150 grit sand paper or a wire brush on the cordless drill and clean them until they are shiny enough your mother would eat off them.

if you come across a cable that is crunchy, throw it away

then when every connection is clean, makes sure they are tight. then seal them with marine electrical varnish.

 

[alldodge]

I actually took the new one and had it tested after it didn't engage. It tested good.

Both doing the same I would look at the flywheel, it might be missing teeth

For the starter to spin it has to extend to engage main power

 

[poconojoe]

Bench test it as suggested and use the boat's battery. This will confirm both are good.

I once had a bad battery cable on a vehicle that had starting problems. The cable almost looked fine, but was corroded on the inside, under the insulation. I cut the suspected cable near the battery and the copper was green. I stripped back the insulation and saw it was corroded pretty far back.
I replace that cable and all was good.