1980 OMC Troubles

BoatMasta

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Aug 2, 2005
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Hi Im having trouble with my 1980 2.5L 4 Cyl. OMC Inboard,<br />where to begin...<br />first thing is when I go to use the stern tilt I just get a clicking sound coming from the cylonoids on the tilt motor the leg won't go up or down unless you tap on the cylonoids and even then it will only go up. <br /><br />Second problem the water pump isnt sucking enough water in and the engine is hitting 180 to aprox. 200 on the temp guage. The water pump is also making a squeaking or squealing sort of noise when the boat is running.<br /><br />Third Problem is the boat wont steer in a straight line unless your going half throttle. <br /><br />Fourth and final is it stalls out when you go to put it in gear or if you put it to 1/2 - full throttle but doesn't when put into reverse. I think that last one is the fuel pump albeit the filters need replacing, I ran it without them and there was little difference, it does however idle irradically almost as though it isnt getting enough fuel.<br /><br />Engine Inboard<br />1980 OMC<br />2.5L 4 Cylinder<br />140 horse<br /><br />Boat <br />17' 1980 Vanguard<br />OMC Throttle<br />Open Bow<br /><br />PS. a note about the engine...it isn't fuel injected which is prob stating the obvious and there is no electronic ignition just the old standard ignition.
 

Phantom17

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Feb 7, 2005
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Re: 1980 OMC Troubles

Welcome to the worst tilt system in the world. You can start by getting a manual. Clean all your connections to the solenoids on the port side of your engine. There is a way to jump the solenoid, but I'll leave that to someone better versed. If you need to use the boat, I'll tell you the way I do mine without a tilt motor in the boat. If you want to fix it, go with new parts. The design is terrible, and unless you have a good trustworthy connection able to test the parts, don't go used.
 

Phantom17

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Re: 1980 OMC Troubles

BTW, is your waterpump noise the engine water pump (circualation) or the impellor pump (in the out drive that sucks up the water through the screen)? They are both easy fixes, but you must start by eliminating probable causes to find the solution. <br /><br />Don't use it til you fix it. Thats a pretty high temp, one that will leave you begging (or paying) for a tow. Mine has never crossed 170.
 

BoatMasta

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Re: 1980 OMC Troubles

The water pump itself as far as I can tell is where the noise is coming from sounds kinda like a bad bearing or something, your right the tilt is the worst from all the things Ive heard about the OMC's and now seeing one. As far as the impeller goes I think its fine no noise really coming from it as far as I can tell, the problems with the boat are from sitting for nearly 15 years with almost no use its probably only got about 100 hours on it.
 

Boomyal

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Aug 16, 2003
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12,072
Re: 1980 OMC Troubles

The OMC tilt is like everything else. It has it's secrets. You learn them and they last for...well at least for thiry years, like mine has.<br /><br />The OMC tilt system has many advantages over all the pipes, hoses, rams, pumps and all that other hooohaw that others have.
 

whywhyzed

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Feb 1, 2005
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Re: 1980 OMC Troubles

you can try running it briefly with the belts off to see if the noise stops.<br />The 2.5 is 120HP<br />The 3.0 is 140HP<br /><br />The water pump on the engine does not suck the water in. It only helps paddle it around the engine.
 

BoatMasta

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Re: 1980 OMC Troubles

"The 2.5 is 120HP The 3.0 is 140HP"<br />Actually according to the manuel for it the engine is a 2.5 140HP and it also says 140 on the engine. i'll try what you suggested though, after sitting for as long as this thing has its probably in about as good of condition as the starter was.
 

Phantom17

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Re: 1980 OMC Troubles

You saying the engine has sat for 15 years? If thats so, you might not want to put too much into it. Your compression is probably low, your tilt system is already in need of repair, and I'm willing to bet your engine water pump is (albeit noisily) pumping what little the impellor is sucking in. <br /><br />Sorry if I soud a bit rough, but I don't know if I'd be too trusting of something that sat around that long, without alot of parts sitting in my basement. Couple with that the fact that replacement units for that drive are (as I quickly learned) more expensive than the boat!!!
 

whywhyzed

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Re: 1980 OMC Troubles

Originally posted by BoatMasta:<br /> "The 2.5 is 120HP The 3.0 is 140HP"<br />Actually according to the manuel for it the engine is a 2.5 140HP and it also says 140 on the engine. i'll try what you suggested though, after sitting for as long as this thing has its probably in about as good of condition as the starter was.
there's a misprint in your manual. If it says 140 on the valve cover, you have a 3.0 Liter engine
 
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