Starter Drive Assembly Failure Symptoms

[Beakster]

Hi, I have a 1980 V4 with the American Bosch starter. https://www.boats.net/catalog/johns...arter-solenoid-american-bosch-17916-20-m030sm

The problem I am seeing is when I try to start the engine, the starter engages with the flywheel but then the flywheel doesn't turn, however the shaft of the starter does turn while the cog is engaged.

Given the starter is turning I suspect something is wrong with the starter drive assembly. Does this have a clutch inside it? Is there a way to test this part? I have found this replacement part but would like to have some confidence it will fix my problem before I order:

Sierra Starter Drive Assembly - 18-5656

Purchase the Sierra Starter Drive Assembly - 18-5656 at Canada's Motorcycle. Free shipping and Easy returns.

fortnine.ca

Thanks

 

[tphoyt]

Does the flywheel turn by hand? Is the battery fully charged and load tested?

 

[Beakster]

Battery fully charged and engine turns by hand. How would I load test ?

 

[Beakster]

I jumped the battery with my truck which is starting fine and engine was running, but same thing. I also tried bypassing solenoid with jumpers and same.

I see a few sparks from the gear on the starter when I'm trying to start it. I suspect it's a bit chewed up.




I've ordered a new one anyway which has the new starter drive on it. I'll swap them out when it arrives and see how it goes.

Amazon.ca

 

[tphoyt]

Probably a good move. In the mean time you can get your battery load tested at most any auto parts store for free if your interested.
Keep us posted.

 

[Beakster]

New starter arrived today. I bolted it on and it turns well and the engine starts.

I'm not sure if the fault in the old one is with the motor or the drive assembly, but I'll hang on to it anyway.

One thing that concerns me is it feels like the teeth aren't fully engaged with the flywheel. Almost like the starter should be a few mms closer to the engine. Is this normal?

 

[Beakster]

So I think this after market starter motor simply had the brackets welded in slightly the wrong place. I thought about cutting them off and rewelding but decided it would be easier to swap the internals of the new motor into the body of the old one.

I cleaned out the old one with electrical contact cleaner and paper, reassembled, and everything works fine and the engagement looks good.

The new body has 4 quarter circles of permanent magnets and the old one had 2 halves. One of the old ones appears to have a crack in one of the magnets but everything seems to be working.