3.0 Mercruiser will not turn over

rivermann

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Jul 21, 2008
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We have a 3.0 mercruiser after sitting this winter the starter will not turn the motor over. It was running when it was winterized and kept in garage all winter got it out and the engine appears to be locked up.Turn the key and the motor turns just a 1/8 of a turn and stops ( the battery is good) took the spark plugs out it still will not turn. Tryed to remove the starter but can not find how it is attached only one bolt is visible. put a bar on the crank end and it still will only turn 1/8 looked in the cylinders they are clean pulled the valve cover everthing looks great. Could the cam or lifters be stuck or could it be the outdrive locked up (the oil was drained before winter)Any help would be great.

Thanks
Tim
 

cheburashka

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May 28, 2005
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Re: 3.0 Mercruiser will not turn over

If the engine turns 1/8 turn, there's a good chance that the problem isn't in the engine itself. It could be that something in the outdrive seized while it was in storage. Have you verified that there's enough lube (and no water) in the outdrive?

The other possibility is that the pistons rusted in their bores. Do you know if the winterizing included fogging the cylinders? Was the boat run in salt water? If it were me, I'd put some penetrating lubricant into each of the cylinders and let it sit for awhile.

Good luck.
 

Kessi

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Re: 3.0 Mercruiser will not turn over

If the starter isn't locked into place then I'd start by removing the out drive and checking the engine again.
I've seen pistons locked in place and a very slight amount of movement from the crank. If that were the case just how bad the cylinder are you can really only tell by opening her up. I have the mentality that it is easier to fix it right the first time.
 

Limited-Time

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Re: 3.0 Mercruiser will not turn over

Pull the spark plugs and make sure theres no water in the cylinders.
 

rivermann

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Re: 3.0 Mercruiser will not turn over

thanks for the reply
We have taken the plugs out there is no water in the engine.
We used a small L.E.D. to look in the cylinders no rust could be found we removed the valve cover everything looks fine we put P.B. baster in the cylinders and down the push rod in case a lifter is stuck let it set over night still no luck. We can not get the starter off any info on how to remove it will help we can only find one bolt I'm sure there is more or it is press into the bell housing and the one bolt holds it there. The out drive was drained when it was winterized but not refilled until this week maybe it is frozen / locked up????
 

Bondo

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Re: 3.0 Mercruiser will not turn over

We can not get the starter off any info on how to remove it

Ayuh,.....

There's 2, 3/8" bolts, Up from the Bottom, at the Aft end of the Starter,....
You'll need a Thin-walled 9/16" Socket for the inside 1....
The out drive was drained when it was winterized but not refilled until this week maybe it is frozen / locked up????

So pull the danm thing Off,... It's only 6 nuts,+ the trim rams....
 

djvan

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May 3, 2003
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Re: 3.0 Mercruiser will not turn over

Ditto on the thin walled 9/16. I got away with removing it with a 6 point 15mm. Re-installed with a brand new custom made 9/16 thin wall. A little time on the grinder and presto---thin walled socket. If your motor is like mine (1986 3.0 140 hp) it was easier for me to remove the inside starter bolt from the port side of the motor.

DougV>
 

rivermann

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Re: 3.0 Mercruiser will not turn over

there are no bolts on the bottom of the starter unless they are recessed and maybe allen head and i tryed allen wrenches up in the one spot but no go. The holes are only about a half of an inch in diameter.

thanks
tim
 

Don S

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62,321
Re: 3.0 Mercruiser will not turn over

If you can't find the 2 starter mounting bolts on a 3.0L, then you really need to find a qualified marine mechanic to work on it. Hopefully you find them.
And why was the drive left empty??? Don't allow whoever did that to work on your boat again.
You may not have a starter problem, perhaps you should follow this link to determing exactly what the problem is.

http://forums.iboats.com/showthread.php?t=167035
 

chiefalen

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May 18, 2008
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Re: 3.0 Mercruiser will not turn over

Put a mirror under the starter. Maybe the heads sheared off the bolts? I hope that didn't happen.

Never leave the drive empty. I hope it's not frozen.

I didn't see anyone ask was oil in the motor over the winter.

The drain plugs were left out or in?

Who winterized the boat?
 

Uraijit

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Re: 3.0 Mercruiser will not turn over

Why are we still talking about a starter? He needs to pull the drive, and see if it will turn over without the drive. If it does, mystery solved. If the starter's engaging and trying to turn it, and he can't turn it by hand, I'd say the starter's probably not the issue.

ETA: For the record (for when you really do have a reason to pull the starter ;) ), this is what your starter looks like. Short bolt on Starboard, long bolt on Port side. Straight across from each other.
http://www.auctiva.com/hostedimages...e=98537708&images=98537708&formats=0&format=0
 

rivermann

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Re: 3.0 Mercruiser will not turn over

Going to pull the out drive tonight. As far as the starter bolts we have looked with mirror there are no bolts under the starter and yes the motor has oil in it we drained it to see if there was water in the crank case and refilled it and replaced the filter. It is common practice we were told to drain an out drive in the fall and refill in the spring in case there is any water in the gear case.
 

Limited-Time

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Re: 3.0 Mercruiser will not turn over

Going to pull the out drive tonight. As far as the starter bolts we have looked with mirror there are no bolts under the starter ........................

Sounds as if the heads have snapped off.:eek::eek: Is there a "L" shaped bracket at the front of starter bolted to both the block and starter?? If so remove it and see if the starter drops down.
 

Maclin

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Re: 3.0 Mercruiser will not turn over

Going to pull the out drive tonight. As far as the starter bolts we have looked with mirror there are no bolts under the starter and yes the motor has oil in it we drained it to see if there was water in the crank case and refilled it and replaced the filter. It is common practice we were told to drain an out drive in the fall and refill in the spring in case there is any water in the gear case.

Either you heard wrong or were listening to some lucky people who were doing it wrong and never had an issue. Common practice is to CHANGE (drain and refill) the fluid in the outdrive before a layup. That gets rid of any accumulated water contamination AND virtually eliminates any chance of corrosion beginning over the layup period. Leaving it dry is an invitation for chemical reactions to start.
 

chiefalen

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Re: 3.0 Mercruiser will not turn over

Ok here we go. Please don't drop the starter yet!

May seem people are yelling at you but they are frustrated for you.

Do you have a manual for this boat engine and drive setup? If not your going to need one.

This is not going to be a one day deal.

Please put the throttle forward as you were going to put in gear.

You will need to remove the lower gear case.

As you look at the drive there is 4 bolts just above the propeller 2 on both sides, remove them please.

Just above the propeller is a hole with a bolt in it, please remove it.

CAUTION: Lower might just drop down and it's heavy.Be prepaid. If the drive is all the way down put a flat piece of wood under the skeg.Than lift the drive with the button on the throttle handle.

If the lower did not drop grab the lower and wiggle it. Still didn't drop?

With a hammer and piece of wood [I use 2 hammers wood handle against the drive and tap the metal head with the other hammer] Tap the lower,GENTLY, GENTLY.

Should drop, please lay on the side away from lower unit, maybe a table.

Nows a good time to raise the drive all the way.

Whats it look like in the lower and the upper?

Please post your results!
 

rivermann

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Re: 3.0 Mercruiser will not turn over

Sorry for the delay finally got time to work on it.
The upper gear case is locked up. there was water in the drive shaft belows the u joint are rusty. I have decide to get a rebuilt unit so where is the best place to get one looking for good quality and a reasonable price.
Thanks for your help.
And yes I'm going to replace the belows and shift cable boot.
Last question should I replace the gimble bearing.
 

Uraijit

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Feb 5, 2008
Messages
884
Re: 3.0 Mercruiser will not turn over

Sorry for the delay finally got time to work on it.
The upper gear case is locked up. there was water in the drive shaft belows the u joint are rusty. I have decide to get a rebuilt unit so where is the best place to get one looking for good quality and a reasonable price.
Thanks for your help.
And yes I'm going to replace the belows and shift cable boot.
Last question should I replace the gimble bearing.

http://www.sterndrive.cc/

Absolutely, replace the gimbal bearing!
 
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