How do you change a belt on an OMC 3.0L ?

Iam2smoov

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Help!<br /><br />I have a 1986 OMC 3.0L stern drive boat and I don't know how to replace the belt. Two of the three pully's are behind what I think is the engine mount. How do you change it? Also, the belt was damaged because it was rubbing against something and burning the rubber. Any ideas why?<br /><br />Thanks!
 

Boatist

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Re: How do you change a belt on an OMC 3.0L ?

Support the engine then You have to remove the bolts to the motor mount and seperate enough you can slip belt in. When you do put on a new belt and a spare so if It ever breaks on the water easy to repair. If the belt were to break you may make it in without the alternator but you need the water pump.<br /><br />If it rubbing then check and make sure the pulleys are all linged up. If one is off then someone may have put a wrong part on. If it was just slipping may have been too loose or you could have a bad bearing in the alternator or water pump.
 

Limited-Time

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Re: How do you change a belt on an OMC 3.0L ?

aa,<br />If it’s the same as a 92'the front engine mount has a removable spacer on the alt. side of the engine. Just remove the 2 bolts from that side of the mount and the spacer should come out. FYI on the 3.0 I changed the belt on the line between the engine mount and the spacer looks like a casting line, could fool ya if ya didn’t know better.
 

Iam2smoov

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Re: How do you change a belt on an OMC 3.0L ?

Thanks for your response. I have a stupid question. Should I use a standard socket set or metric? Also, how many bolts do I have to remove?
 

Limited-Time

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Re: How do you change a belt on an OMC 3.0L ?

aa,<br /> There were 2 bolts on the 3.0 I worked on and I used either a 9/16 or 5/8" socket. You may have to loosen the bottom bolt (pivot point) on the alt. as well as the one that allows for the adjustment on top. Good luck.
 

Iam2smoov

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Re: How do you change a belt on an OMC 3.0L ?

Thanks L-T,<br /><br />I'm going to try to do this thing myself. I'm going to put a 2x4 underneath to support the engine. So I just loosen the mounting bolts on the alternator side? Would that be enough space to slide the belt through?
 

Limited-Time

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Re: How do you change a belt on an OMC 3.0L ?

aa,<br />You will be removing the two bolts on the alt. side of the engine mount completely. The bolts on the opposite side will support the engine; there should be no need for the 2X4. When you loosen both bolts you should be able to move the spacer slightly. Make sure you have a hold on the spacer before you fully remove the bolts, otherwise it may end up under your engine in your bilge.<br /><br />aa, bondo covers the same issue in this thd.<br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=24;t=010757
 

Iam2smoov

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Re: How do you change a belt on an OMC 3.0L ?

Thank L-T,<br />I appreciate your help and I will let you know how it goes.
 

Phantom17

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Re: How do you change a belt on an OMC 3.0L ?

I have a manual if you want to buy it. I ended up buying a 400 series outdrive and dont need the cobra one. let me know if your interested.
 

Iam2smoov

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Re: How do you change a belt on an OMC 3.0L ?

I don't think that it's a Cobra drive, but do you think that there would be a big difference between the Cobra and Stringer drives?
 

Boatist

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Re: How do you change a belt on an OMC 3.0L ?

If it is an 1986 Should be a cobra but easy to tell the difference.<br />400 Stringer, to trim the outdrive it raises the front of the engine. It has a big rubber boot on the transom and the tilt is done with a big 1/4 circle gear on the port side of the outdrive.<br /><br />Cobra front of the motor is fixed and does not raise up and down. No big rubber boot on the transom. Trim and tilt done by 2 hydraulic rams just above the caviation plate.<br /><br />Engine is not that different but the outdrive is completely different. The way the engine mounts is different.
 

Iam2smoov

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Re: How do you change a belt on an OMC 3.0L ?

It has the rubber boot, so I think it's the Stringer model. With everyones help, I was able to change the belt succesfully. :) Thank you all!!!The only problem that I had was that the spacers kept falling out in the bilge. I smiled because "Limited-Time" said that it might happen and it sure did. I put on a spare belt and tied it up out of the way. After running for about 20 minutes, I noticed that the new belt started fraying around the edges. I don't know if it was rubbing up against something or not, but I'm not going to worry about it now because I have a spare. :) Thanks everyone!
 

Phantom17

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Re: How do you change a belt on an OMC 3.0L ?

Hope it doesn't break in the water, or "fray" anything else. You might want to be sure you have the right ones. Good luck.
 

Limited-Time

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Re: How do you change a belt on an OMC 3.0L ?

aa, <br /> Ya need to figure out whats causing the belt to fray. If the belt fails and stops driving the water pump your engine can/will over heat. If you don't catch it in time you will do major damage to your engine. Ya got changing the belt down, now lets see what the source of the problem is. It could be something as simlple as rusted pullies.
 

Iam2smoov

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Re: How do you change a belt on an OMC 3.0L ?

How would I find out what size the belt should be?
 
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