Mercruiser Starter Issue? - spins but no crank

OneFoot81

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Aug 30, 2011
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So, When I turn the key the starter spins (sounds like a whiiiiine) but the engine does not crank. So the starter is not engaging the flywheel? Does this mean a new starter? anything else I should try/culprits to look for?

Things I have tried:
(Mercruiser 1994 Alpha One)

Gages work.
Battery is good, even swapped it out to same result.
Disconnected all battery connections, slave and starter solenoid connections, brushed them and re-tightened.
Jumped from the battery to the small terminal with yellow wire on the slave solenoid and got the same result.
Jumped to the big terminal, got some sparks and same result.

Any help appreciated!!
 

Bt Doctur

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19,291
Re: Mercruiser Starter Issue? - spins but no crank

starter shaft broken
bendix drive damaged
bendix drive not moving outward ,bad solenoid
missing teeth on bendix, flywheel or both
broken crankshaft, missing/sheared flywheel bolts
 

makonnen

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Apr 4, 2012
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184
Re: Mercruiser Starter Issue? - spins but no crank

Add one more, one way clutch that allows the flywheel to overrun the starter drive is not holding.

New starter if that is the case.
 

cr2k

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3,730
Re: Mercruiser Starter Issue? - spins but no crank

Move the engine over by hand or bar so the flywheel is in a different position. If it starts after that your ring gear has a bad spot. Ring gear replacement requires engine removal. If it does the same whine replace your starter with a MARINE starter as a automotive will work but could blow up (as in fire and explosion) your boat.
 

ENSIGN

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Re: Mercruiser Starter Issue? - spins but no crank

Remove the starter and check the teeth on the ring gear all the way around
 

OneFoot81

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Re: Mercruiser Starter Issue? - spins but no crank

Thanks to all

I will do the ring gear test cr2k suggests, then I will take the starter off, and see what I see.
 

southwest395

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Re: Mercruiser Starter Issue? - spins but no crank

Sounds like its time for a new starter.
 

OneFoot81

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Re: Mercruiser Starter Issue? - spins but no crank

So I removed the starter, looked at the ring gear and snapped a few pictures:
ring gear 1.JPGring gear 2.JPGring gear 4.JPGring gear3.JPGstarter 1.JPG

Can anyone tell me if this is normal? I suspect not.....but never seen one before :confused: (dang please say yes, right now i would love to just replace the starter and be done with this!!!!)
 

makonnen

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Re: Mercruiser Starter Issue? - spins but no crank

No, the ring gear is totally screwed - no teeth. You can see the remnants of the teeth in the grey sludge around the ring gear.

New starter.
 

OneFoot81

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Re: Mercruiser Starter Issue? - spins but no crank

Thanks!

I will get a new starter
 

Bt Doctur

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Re: Mercruiser Starter Issue? - spins but no crank

better look closer, the motor was taken apart, that hole locates the shaft so it contacts the 3 gears. the bendix drive is in front of all that.
the ring gear we referr to is the flywheels ring gear or teeth.D is called the bendix drive
hitork.jpg
 

Bt Doctur

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Re: Mercruiser Starter Issue? - spins but no crank

Got to get new glasses, missed the missing teeth on the gear.
 

makonnen

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Re: Mercruiser Starter Issue? - spins but no crank

Yea all the teeth are ground into a grey pulp ...

For the record I wouldn't be messing around with replacing just the ring gear. Gears are generally build to have a soft malleable core and very hard brittle outer surface. I would bet that the hard outwer surface of the planetary gears are worn / wearing away due to grinding the metal pulp.

Play it safe, buy a new or refurbished started from a reputable source.
 

OneFoot81

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Re: Mercruiser Starter Issue? - spins but no crank

better look closer, the motor was taken apart, that hole locates the shaft so it contacts the 3 gears. the bendix drive is in front of all that.
So you are thinking the bendix is likely a problem as well. I am still a bit confused about where the bendix is or if I still have on there....I did not take it apart much more, but I am thinking that if there appear to be multiple problems with the starter (and it looks a bit rough from all i have seen, picured below) I am thinking that it would be simpler to get a new one.

Mischief-thanks for the heads up, but as i was saying above, the whole unit looks a bit gunked, and at the moment I would rather spend a bit more to stave of any future issues. Go boating, then try to rebuild this old starter this winter. im new at this, so figureing out stuff takes long!


the ring gear we referr to is the flywheels ring gear or teeth

Yes, my main concern right now is if the starter is not the whole issue, if there is another problem as some have stated, such as the teeth of the flywheel (ring gear). I checked out the exposed portion of the flywheel, all looks good, maybe some nicks that looked relatively fresh, but no chips? in order to look at the rest of the flywheel- I am a little confused still about how to manully crank the engine, mine does not appear to have a big hex bolt in the center, a little confused about the bar method......

HPIM3567.jpgHPIM3568.JPG
 

southwest395

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137
Re: Mercruiser Starter Issue? - spins but no crank

Buy a new or refurbished marine starter. Not a normal car starter they wont last long.
 

Mischief Managed

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1,928
Re: Mercruiser Starter Issue? - spins but no crank

Yea all the teeth are ground into a grey pulp ...

For the record I wouldn't be messing around with replacing just the ring gear. Gears are generally build to have a soft malleable core and very hard brittle outer surface. I would bet that the hard outwer surface of the planetary gears are worn / wearing away due to grinding the metal pulp.

Play it safe, buy a new or refurbished started from a reputable source.

The ring gear is plastic in those starters. The planetary gears are metal though.
 

Mischief Managed

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Re: Mercruiser Starter Issue? - spins but no crank

Mischief-thanks for the heads up, but as i was saying above, the whole unit looks a bit gunked, and at the moment I would rather spend a bit more to stave of any future issues. Go boating, then try to rebuild this old starter this winter. im new at this, so figureing out stuff takes long!

I think that's a good plan. Don't over think the issue. The ring gear in the starter is a known weak point and it's obvious why it's not spinning the engine over. That said, if it may have failed because of a water in the cylinders, so when you replace it, pull the spark plugs out on the first crank, just in case.
 

OneFoot81

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Re: Mercruiser Starter Issue? - spins but no crank

Thanks for the heads up-will do.
 

OneFoot81

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Re: Mercruiser Starter Issue? - spins but no crank

So looking at Starters - got a quotte from my local mercruiser parts shop for ~$230 for a starter.

Found one online for ~$60 aftermarket
http://www.ebay.com/itm/NEW-Mercrui..._Accessories_Gear&hash=item1e67a1c4ed&vxp=mtr

Im inclined to go with the mercruiser part, but is there any difference here? one is way cheaper. Probably made in china, but then again they both probably are.
 
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