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OMC 2.5 liter engine removal

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Dan_mcfly

New member
Trying to separate the engine from bell housing. The dowel pins are free the engine rocks a bit on the bell housing but won't separate. What am I missing, is there a bolt or pin that holds the drive shaft in?

Unsure of the year of OMC, late 70's early 80's perhaps.

Dan
 
There are 6 screws or is it 4 screws and 2 bolts. They hold the bell housing to the engine itself. The 2 bolts are grounds.

Did you remove the flywheel cover another 5 screws maybe 4.

Then did you remove the 2 bolts holding the base of the front mount or the center nut on top of the front mount ?

Did you remove the drive shaft ?

See that shaft could be frozen in the one piece coupler.

Or are you removing the motor without removing the drive.

If the latter then you have to tie up the drive or with the drive fully down and a flat piece of wood under the skeg crank the bow up till the skeg rests on the wood, see the drive weight will bind the coupler and the shaft spines.

Awaiting your reply. Then we can go from your reply.
 
chiefalen said:
There are 6 screws or is it 4 screws and 2 bolts. They hold the bell housing to the engine itself. The 2 bolts are grounds.

Did you remove the flywheel cover another 5 screws maybe 4.

Then did you remove the 2 bolts holding the base of the front mount or the center nut on top of the front mount ?

Did you remove the drive shaft ?

See that shaft could be frozen in the one piece coupler.

Or are you removing the motor without removing the drive.

If the latter then you have to tie up the drive or with the drive fully down and a flat piece of wood under the skeg crank the bow up till the skeg rests on the wood, see the drive weight will bind the coupler and the shaft spines.

Awaiting your reply. Then we can go from your reply.
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Removing the motor without the drive. Everything was off, flywheel, bell housing bolts etc.

It must have been pinching the drive a bit at the coupler we now have the engine out. Thanks for the advice.

Now looking for parts, where the heck do I go for a used engine block, this one is cracked? Looks like a mud dauber packed the block drain petcock with mud. Apparently no one caught the problem. The heat exchanger appears okay. Will also need gaskets at some point.

Dan
 
never saw a 2.5 with a heat exchanger. You sure it's a 2.5. If it is i would search for a 3.0 any year till 90. Doesn't matter the make. Use your mani' riser ' and carb all in one piece. the flywheel coupler also use the bolts from the omc flywheel.
 
michigan motorz has NO coupler for a 1970's or early 80's OMC

their motors will NOT work in this instance.

You need to find a pre 1990 engine. suggest used that can be heard running and take a compression tester and you know where to look for cracks
 
read the link they say they have a solution, 145 dollars for a flywheel, and they say they have the coupler.

Jst repeating what i saw on the site.
 
Thanks to everyone for their responses. We did find a used 2.5 liter Iron Duke as a replacement engine, have to check it out first, check compression etc.

Dan
 
why go with a old 2.5, for the same money get a good used 3.0 will give you up to 20 hp more, i went thru what your doing, once you feel it in your boat you will wonder why you would have even considered getting another 2.5
 
chiefalen said:
why go with a old 2.5, for the same money get a good used 3.0 will give you up to 20 hp more, i went thru what your doing, once you feel it in your boat you will wonder why you would have even considered getting another 2.5
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You make a good point, it's just that a used 2.5 was readily available for $275 delivered to my doorstep, and the customer was okay with the deal.

Don't know if this 2.5 is in decent shape, if it isn't maybe the 3.0 would be an option. The mentioning of changing the flywheel and such wasn't helpful towards the 3.0 conversion. As long as he can putt around the lake and maybe tow a single skier he'll be happy.
 
i paid 400 with a good 3.0 and i had to take the boat and the trailer. Kept the trailer and motor, stripped the boat and got rid of the hull.

Just saw a good 3.0 on ebay do a search
 
chiefalen said:
MERCRUISER, OMC, 2.5, 3.0L (120-140) MARINE MOTOR : eBay Motors (item 190400522676 end time Jun-03-10 19:30:00 PDT)

This would be exactly what i would buy if i needed a 3.0 i happen to have the 140 same as the one in the auction i am more then satisfied.

Tell the customer that for a few dollars more he will get 20 more hp, people do all kinds of stuff spend thousands for 20 more hp.
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The customer is satisfied, however, if YOU were to pay difference between a $275 boat (with 2.5 liter motor) that we already have against the reserve amount for the engine above, likely $800 or better. Plus pay me to switch over the exhaust elbow, remove the flywheel housing and anything else that's needed to make it work.....then maybe the customer might be interested.

Actually he would like a waterworthy boat ASAP, so fartin around with trying to find a CHEAP 3.0 plus adapt anything that's needed isn't in the cards.

Dan
 
Hey guys I am trying to pull my 2.5 liter out of my star craft and it seems stuck as well. I was curious though, do I have to un bolt the fly wheel? I unbolted the bell housing and all electrical. The Seloc manual said to move the engine forward 6 inches then it should come right out but my engine will only separate from the bell housing about an inch. My outdrive is still attached and raised or tilted up. Do I have to put the throttle in neutral or some other position?

Please advise.
 
might want to start a new thread, coltsfan with year and drive model - stringer or cobra
this thread is from 2010
 
If you have a stringer and do not wish to remove the drive, you must first remove the flywheel cover to pull just the motor and leave the bell housing in place.

Can be a cobra it had a 2.5 motor in front.

So for this thread i think you have a stringer.

Lower the drive all the way, place a flat piece of wood under the skeg and raise the trailer till the skeg touch's the wood.

Now the drive can't drop and jam the shaft.

If it is a cobra, i would recommend removing it and removing the motor. You need to inspect the gimbel,ujoint, and all the rubber.

But the motor can be removed without removing the drive.

You can now raise the drive a bit and pull the motor forward the 6 inch's you need to clear the coupler.

I leave the front mount on and remove the " t " bolts into the stringers However if you don't have room then remove the entire front mount.

Note: This is a old piece of iron and the shaft maybe rusted into the coupler.

So if this is the case you may need to remove the drive. If a stringer read below:

Looking at the drive from behind, see the rubber bumpers, with the drive fully down and touching the flat wood gently remove the, rubber bumpers mark them they must go on exactly as they came off.

You will see trunion caps both sides remove the trunion caps.

Now with someone else jacking the trailer up 1-2 inch's the drive will just come off the trunions, if the cable is on the port side pull the drive over enough to expose the ball gear. If electric shift pull the drive over to the starboard side.

Gentle with the cable you will have enough room. Tie the drive to the boat somehow i tied to my swim platform.

Now remove the ball gear cover, and then the bolts holding the bearing carrier.

Now pry out the ball gear and shaft all in one piece with a flat piece of wood between the pry bar and the transom.

Now the shaft the bearings and ball gear all came out in one piece put it aside.

Now the motor will move.

Good luck..

More questions please post them, all here are ready to help you.
 
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