Engine spins but boat loses thrust

[Stinger2]

Boat has been sitting for 3 years, first trip out, motor runs great, but just as it is about to get on plane, engine free revs like it is neutral but no power getting to the prop. I suspect engine coupler, but pulled outdrive, shined light in there, splines look good. any ideas? Its an 86 CC Stinger with Alpha one and 383 stroker

 

[I/O WALDO]

Re: Engine spins but boat loses thrust

When a coupler spins,unless the splines R dry or the drive is WAY outta line,there is usually no spline damage to the coupler.The splined piece in the coupler spins against the rubber bushing outside of it.When a coupler spins,under load like yours,U can smell burning rubber in the engine box.Could bee your prop bushing spinning!

 

[Mischief Managed]

Re: Engine spins but boat loses thrust

You likely spun the hub in tthe prop. There's typically a rubber hub in there that is designed to give rather than let the prop or shaft get wrecked upon contact with something solid. An old dried out hub combined with a lot of engine torque would could spin pretty easily. Any prop shop can re-hub the thing for ya.<br /><br />Otherwise, the prop is ventilating, perhaps on exhaust gas. Is it a vented prop?

 

[crazy charlie]

Re: Engine spins but boat loses thrust

Time to either get the prop hub reconditioned or get a new prop.

 

[Stinger2]

Re: Engine spins but boat loses thrust

I hope you guys are right that is the prop...I don't recall smelling any burning rubber and I did have the engine hatch open while I was running it. I don't feel like removing the engine to replace a coupler. Slapping on a new prop would be a lot easier.

 

[KRS]

Re: Engine spins but boat loses thrust

If the hub is spun, then your impeller isn't spinning, which means you aren't circulating water, which means overheat (if you are raw water cooled).<br /><br />What was your temperature gauge reading?<br /><br />Easy to check on the muffs, see if water is coming out of the exhaust while it's running, but don't burn up your motor.<br /><br />By the way... exact same thing happened to me. Turned out the engine was torque rolling because the mounts were loose/broken and had bad wood. And mine is only one year newer than yours

 

[bruceb58]

Re: Engine spins but boat loses thrust

I think KRS meant if your coupler has spun you can overheat.

 

[KRS]

Re: Engine spins but boat loses thrust

The boat AND you

 

[Stinger2]

Re: Engine spins but boat loses thrust

Took the prop to my prop guy, he was able to turn the hub with a breaker bar, hub is indeed shot!!! I was about to yank the motor to replace the coupler, you guys just saved me a bunch of time and money!!! Thanks guys.