Spinning Prop, or more serious?

[lwhssh]

1999 BL Trophy 2352
5.0 Mercruiser w/ Alpha II

First time out boat ran like a champ. However on 2 different occasions out of nowhere the engine reved high. I was motoring at about 4000 - 4500 rpm pushing strong. Then the engine reved real high like it popped into neutral. I pulled back on the throttle and I was back in business.

I though I may have spun the prop. Any opinions?
Thanks LWH

 

[Don S]

Re: Spinning Prop, or more serious?

If you had spun a prop hub, you wouldn't have gotten back on plane. Maybe it did go to neutral. Have you had any shifting or stalling problems lately?

 

[lwhssh]

Re: Spinning Prop, or more serious?

This was the first time out. The boat is new to me. I had a good mechanic repair some things and go over everything. It really ran great. Shift from N to F to R were all crisp.
First time I thought maybe it was cavitation as I went up over another boats wake.

 

[lwhssh]

Re: Spinning Prop, or more serious?

I wish I could recall if I grabbed the throttle and put it back to neutral or just let up on the throttle. I can't remember. I would think that could mean something.

 

[chiefalen]

Re: Spinning Prop, or more serious?

when u jumped the wave for a split second or 2 the outdrive comes out of the water.has to rev high.just like a car going real fast and jumps a hill revs high for a split second.you were probably doing 45-50 at the time.

 

[Muqwump]

Re: Spinning Prop, or more serious?

Sounds like you (more than likely) you just cavitated. If the prop would have spun, you would be going back to the dock real slow with a loss of thrust and would have maintaned higher RPM'S . If it was a more serious condition, you wouldnt have made it back.