Hydrofoil the answer?

[KCShorty]

My '82 14ft Lund has a '82 Johnson 25hp on it. I had 4 people in it the couple weeks back and when I went to give it throttle, I think it started cavitating. The motor raced and lost speed/power. I am going to pull the prop and have a local marine prop place check it out for me. Do you think the hydrofoil might help? Looking at the Doel Fin and the Stong Ray Jr., but cant tell which is better for my application.

 

[wilde1j]

Re: Hydrofoil the answer?

If you have a spun prop hub, no fin will help. You will lose some top end speed with a fin in any case.

 

[KCShorty]

Re: Hydrofoil the answer?

If you have a spun prop hub, no fin will help. You will lose some top end speed with a fin in any case.

What does a spun prop hub look like? I pulled the prop. Not sure what ist supposed to look like inside. The prop only has splines on the last 1inch. Is it supposed to have them the entire lenth ?

 

[Daviet]

Re: Hydrofoil the answer?

It is hard to see the hub in a lot of cases. It is a rubber bushing between the splined hub and the prop itself. Use a scribe or waterproof marker and make a mark accross the inner splined hub accross to the prop itself. Install the prop back on the engine and run it till it happens again, remove the prop and look at the line, is it still aligned or has it moved? If it moved the hub has spun. Get another prop or have yours rehubbed.

 

[KCShorty]

Re: Hydrofoil the answer?

It is hard to see the hub in a lot of cases. It is a rubber bushing between the splined hub and the prop itself. Use a scribe or waterproof marker and make a mark accross the inner splined hub accross to the prop itself. Install the prop back on the engine and run it till it happens again, remove the prop and look at the line, is it still aligned or has it moved? If it moved the hub has spun. Get another prop or have yours rehubbed.

I will give that a try. Thank you

 

[Daviet]

Re: Hydrofoil the answer?

You bet, let us know what you find.