Unusual powering down

[pvbearcat234]

I get out on the water and throttle up. Will be cruising 25 mph and will slow down to 10-15 for no reason. Is not reliable, Engine is not missing just slowing down. Temp seems ok, oil pressure fine, rpm on engine slows some but not significantly. <br /><br />The engine is a 3.0 litre OMC.

 

[achris]

Re: Unusual powering down

Not an OMCspert, but if the rpm doesn't change, it could be slipping clutches or a slipping prop hub.<br /><br />Can you tell us what year it is, or if it's a stringer or cobra?<br /><br />Chris...........

 

[WillyBWright]

Re: Unusual powering down

Don't hold me to this, but I don't think they put 3.0s on Stringers. Those would've been Chevy 2.5s or maybe Ford 2.3s. The Cobra 3.0s use a fairly small prop. I wouldn't be suprised if the prop hub spun. Could also be a spun engine coupler if the motor alignment is off.

 

[cobra 3.0]

Re: Unusual powering down

I have a 1986 3.0 OMC Cobra and use a 17" pitch prop for skiing/tubing...sometimes a 19" pitch for light loads. I does sound like a spun hub. You can put a mark on the prop and hub and see if the rubber hub has spun after a little run on the water.

 

[motox6]

Re: Unusual powering down

How is your trim? My trim went belly up out on the water and I only got 2000 RPM until I fixed it