Damaged teeth on Mercrusier 470, 170 hp.

Dmoadus

Cadet
Joined
May 26, 2011
Messages
8
I recently bought this boat which is in great all around shape. However, it stranded me when it failed to restart after running for about 10 minutes. It acted exactly like the battery was dead. After buying a new battery and not solving the problem, I found that the starter gear was sticking in the flywheel and not allowing the starter to "spin up" before engaging the engine. I ordered a new starter and while waiting for it to be delivered, I decided to take a look at the flywheel's teeth. They were virtually like new until I discovered a section of about 10 teeth that were missing about a third of the width of the teeth. My starter is the old Prestolite which has an external solenoid. I'm hoping that I will be able to continue using the flywheel for a while, (maybe change it this winter). Has anyone any experience with such damage? I kind of think that with the new start engaging properly that even if it lands on the bad section, enough of the strength of the remaining teeth will allow my engine to still start. Any one care to offer a forecast?
 

Bondo

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Apr 17, 2002
Messages
71,366
Re: Damaged teeth on Mercrusier 470, 170 hp.

I recently bought this boat which is in great all around shape. However, it stranded me when it failed to restart after running for about 10 minutes. It acted exactly like the battery was dead. After buying a new battery and not solving the problem, I found that the starter gear was sticking in the flywheel and not allowing the starter to "spin up" before engaging the engine. I ordered a new starter and while waiting for it to be delivered, I decided to take a look at the flywheel's teeth. They were virtually like new until I discovered a section of about 10 teeth that were missing about a third of the width of the teeth. My starter is the old Prestolite which has an external solenoid. I'm hoping that I will be able to continue using the flywheel for a while, (maybe change it this winter). Has anyone any experience with such damage? I kind of think that with the new start engaging properly that even if it lands on the bad section, enough of the strength of the remaining teeth will allow my engine to still start. Any one care to offer a forecast?

Ayuh,... Replace the ring gear...

The odds are the motor will stop in that location 99% of the time...
 
Joined
Mar 27, 2010
Messages
3,028
Re: Damaged teeth on Mercrusier 470, 170 hp.

HA, thats a recipe for getting you stranded. My first car as a teenager had a ring gear with one or two broken teeth on it, not as many as yours. I kept the dust cover off the flywheel cause every week or two it would stop right there on that spot where was no tooth and bang.... nada.

I had to reach under and turn the flywheel a little by hand and she would start. Kinda sucked when it was raining out or on a date. Excuse me I gotta go turn my flywheel. Ah the good ol days!

With that many missing teeth it's gonna happen more to you than it did me.
 

Randy J

Petty Officer 2nd Class
Joined
Oct 24, 2009
Messages
170
Re: Damaged teeth on Mercrusier 470, 170 hp.

it boils down to pull it and either can flip the ring gear off fly wheel and reinstall using the unused other side or take it to auto zone and buy a new ring gear and have it pressed back on at a machine shop..
 

Bondo

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Apr 17, 2002
Messages
71,366
Re: Damaged teeth on Mercrusier 470, 170 hp.

and have it pressed back on at a machine shop..

Naw,... Just heat it to 400? in the ole lady's oven, 'n it'll fall into place...
 
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