1988 OMC Cobra 3.0L engine revs/slipping

[jabraham]

Hello, my first post here…I recently purchased a four winns boat that has a OMC 3.0L and I took it out on the water the today and once I would get past 1/2 throttle or so the engine would rev up and sounded like a slipping clutch and the boat would not move any faster. Also noticed that the temp gauge went up to close to 220 or so. After I slowed down to a slow speed/light throttle, the temp went down. Any help or guidance would be appreciated. Thank you!
Jason

 

[Scott Danforth]

My guess your coupler is toast

However based on 220 degrees, every bit of rubber in the exhaust path is also burnt toast ( no cooling water means your exhaust goes from 250 degrees to 1200 degrees)

 

[kenny nunez]

It might be the drive coupler. Reach behind the engine and feel around the shaft where it engages the coupler. If the coupler is the problem you will get some black sticky material on your hand.

 

[hugh g]

Look in the bilge for black dust which is another sign that the coupler grenaded.

 

[bruceb58]

Sounds like a spun prop hub. A coupler would be all or noting.

 

[jabraham]

Thanks for all your input!! I will check the prop hub first and go from there. Thanks again!!

 

[bruceb58]

Thanks for all your input!! I will check the prop hub first and go from there. Thanks again!!

A spun prop hub is not the reason your temp got up high. Change your impeller.

 

[hugh g]

Thanks for all your input!! I will check the prop hub first and go from there. Thanks again!!

Just switch out the prop with your spare.