2 spun props

[FREDSDOG]

I have a 1989 25 larson san marino with a 305lx and alpha drive. I just spun 2 props on 2 consecutive trips. One was a 14 1/2 x 15 stainless. The other was a 15 x 14 aluminum. WOT with either prop is about 4300. Engine runs at about 180. Did not hit anything first one spun powering up to plane the other spun at about 3800 rpm steady. Any ideas?

 

[Dhadley]

Re: 2 spun props

Could be just fate or there could be a reason. If the rubber hubs look burned then there could be a lack of cooling water in the exhaust - assuming the exhaust does indeed go thru the drive. If you have thru transom exhaust it doesn't apply. We'll also assume you have the right forward thrust washer.

Do the hubs appear burned? have the hubs been replaced lately (recently, before they spun?)

 

[Bob_VT]

Re: 2 spun props

Check your drive coupler. Have you smelled any burning rubber? Are you sure the prop hubs ares spun?

 

[jeffersondodson561]

Re: 2 spun props

you mmight want to drop a couple of pitches you should be turning around 4800

 

[Bondo]

Re: 2 spun props

you mmight want to drop a couple of pitches you should be turning around 4800

Ayuh,.. Might need to regear the drive,...
Props for outdrives don't get no smaller than that....

We need more Info Fred....

 

[jason32038]

Re: 2 spun props

Sounds like you're having engine troubles also. Should be turning more rpm with that engine and those props.

 

[kenmyfam]

Re: 2 spun props

Check that the prop is truly "spun" to begin with. Mark it up and see if it moves.

 

[5150abf]

Re: 2 spun props

I would be pretty stunned if you actually spun 2 props in a row, I have ripped blades off props and had countless bottom hits and have never once spun a prop, I have exploded 2 lowers but never a prop spun.

Have you tried marking the prop, make a mark the goes clear across the back of the prop making sure that mark the prop and hub, run the boat till it slips then check to see if your marks are lined up, if they are you have a different problem, if they aren't it is spun.

Are you sure you aren't trimmed up to much and cavitating?

 

[jeffersondodson561]

Re: 2 spun props

You have your thrust hub on right, and did you say your running at 180 degrees? If so this is too hot, actual temp. Is this a gauge reading or have you verified with pyrometer gun? You might have a flapper that has burned off blocking cooling water. You will have to pull drive to verify.