Spun Prop?

[Fish Head]

I have a 20ft. 2000,Bennington Pontoon boat with a 2000 70hp johnson outboard. How can I tell if the prop is spun. At higher speeds,about 5,000 Rpm the motor seems to suddenly sound like its winding up, when I throttle back it gets better.(I thought I may have run a ground or got weeds in the prop when it first happened)even when idling the motor seems like it works harder than normal.Checked the lower unit oil and it looks fine.Any thoughts? <br />Thanks

 

[Fouled Plug]

Re: Spun Prop?

Paint or scribe a line between prop rim and hub. After a few starts/stops, if the lines don't match up the hub is toast.

 

[OBJ]

Re: Spun Prop?

Hey Fish Head...How ya doin'?<br /><br />Could be your prop is sucking air. Ventilating. Usually, when a hub is spun, the engine will rev with no increase in speed. This will happen at some rpm above idle rpm. 5000 rpm does not sound like a spun hub. But "stuff" does happen. Read on.<br /><br />From the rpms' ya' posted, I don't think the hub is spun. What kind of trim do you run? If you are trimmed up, try trimming down a little. <br /><br />If this does not cure the problem, a four blade prop may be the answer. Is the engine mounted high on the transom? If so, it may be to high. Droping down a hole may help. Look at the set up and what I've posted and get back to us.