Mercruiser 350 MAG flywheel removal

Mauro Brisola

Seaman Apprentice
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Jun 13, 2016
Messages
31
The starter of my 2012 350 MAG started to "slip". Starter runs but will not rotate engine. I removed starter to fix it. Problem is bench testing starter, it is just OK.

Considering some months ago engine had a hydrolock situation I suppose that probably the starting problem is flywheel ring gear related. Stripped teeth maybe. Despite starter was working normally after the hydrolock it was kind of abused that day. I can't check ring gear condition right now because marina where boat stays is 80 miles from home...

My business is auto repair. Then, despite I'm still learning about inboards and sterndrives, the boat DIY is fun for me.

My (basic / silly) question is:

- In the case of flywheel removal engine removal is a must??? Or it is possible to remove flywheel with engine in place?

Engine bay is tight (27 feet cuddy - Bravo Three)

Thank you
 
Last edited:

Bondo

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Apr 17, 2002
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Or it is possible to remove flywheel with engine in place?

Ayuh,..... Welcome Aboard,.... Nope, the motor has to come out, or atleast move forward enough to pull the coupler, flywheel cover, 'n the flywheel,....
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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Jul 23, 2011
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51,251
Drive off, motor out, r&r ring gear, reinstall motor, align motor, reinstall drive,

Drive needs to come off, motor needs to be aligned.

However before I pulled the motor, I would visually inspect the ring gear
 

NHGuy

Captain
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May 21, 2009
Messages
3,631
Yup, you can get a crank device on the front pulley or remove it and use a socket on the nose. Maybe remove the spark plugs too so it turns over easily.
I imagine it would be hard to see the ring gear in the starter window. If you have a go pro you could avoid removing the exhaust manifold to see the ring.
Engines are easier to remove from some boats with those big manifolds out of the way. So it wouldn't be a bad thing to remove them both once you are getting ready to pull the engine.
 

Mauro Brisola

Seaman Apprentice
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Jun 13, 2016
Messages
31
Thanks a lot for the answers. Next weekend I'll travel to marina to check the ring teeth.
 

Fishermark

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Oct 19, 2003
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5,617
The starter of my 2012 350 MAG started to "slip". Starter runs but will not rotate engine. I removed starter to fix it. Problem is bench testing starter, it is just OK...

If your bendix is slipping, then bench testing the starter will not really tell you anything. It may still be just a bad starter.
 
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