old propellors

[lurch]

Hi guys

Can anyone shed some light on when a prop is no longer doing the buisness and should be replaced .

Mine is fine at below planing speed , and above say 20 knots but inbetween when its trying to get out of the hole and up to speed seems to have a fair amount of cavitation .

I am not sure if this is due to some kind of prop problem or if it is something else , the prop in question is a S/S prop but im not sure how old it is .

When do you expect to change them ?

Apart from damaged or cracked props do they have a life ??

Thanks

Peter

[Burley_Boy]

I'm not an expert but I have found that the aluminium ones at least will wear out and basically have less surface area left pushing the water, they will then not have enough pressure against the blades and you will find that the revs will be higher for the same speed. They will also cavitate a lot easier when worn. If you have a smaller blade then I think the pitch has to be adjusted to get the correct behaviour you at least have to have the right pitch for the motor. If you find your revs are too high when you push the boat flat stick then my guess is a prop issue.

There are some guys who are magicians with props and know their stuff. I took mine to a prop guy in Southport on the Gold Coast and he could tell me exactly what pitch the prop should be on my setup and was quite happy to repair and adjust the pitch of the prop accordingly, think he charged me about $30 a few years ago worked a treat! Brilliant.