1998 90hp bf90 cavatation / clutch problems ??????? help please!

today when i was fishing i was running up the river with my 90 hp honda (year 98) and the motor was acting like it was cavitating. but when i would lower the rpm's and then slowly raise them i could get the motor to run at 5500 rpm. but when i would dump the throttle like i was going to pull a skier out of the water it would over rev, like a clutch was slipping ???? is there a clutch on my motor????? my motor has 940 hours on it and i have never have had this happen before. im running a stainless steel prop that has no nicks or chips but is over 5 years old with aprox 500 hours on it.

If the propeller has any chips, dings, Pin holes or chunks missing on the leading edge, chances are it is cavitation. When ever someone told me there prop was in good shape, it usually was not. Are there any pieces broken off the ventilation plate on the lower unit?

Hi,

I think you will find the rubber bush in the prop has spun. You will need to have it replaced, or fit another prop

Cheers
john

Dockside, the prop is in like new condition on the leading edges no dings or scrapes. also nothing wrong with the ventilation plate or trim tab. thank you for your post !

Dinghyworld, im taking the prop to my prop shop where i purchased the prop to have them look at it tomorrow. they told me if it was fubar they could fix it in 10 minute's i will post what i find out! thank you for your reply on my post!

Sure sounds like a bad prop !!------------Cheaper than overhauling the lower unit too !

ok every one,took the prop to my prop shop and yes the hub was bad!! seeing it is an older prop it will be a couple weeks before they can get me a new hub and press it in. but the guy there was totally cool and gave me a loaner prop to use so i can keep fishing!!!! now thats good business!!! now off to catch some salmon!!!!!!