GW 275 Tournament Cavitation Problem

[Patent Pending]

I have a newly acquired 2007 GW 275 powered by twin Yamaha 150's. Performance is great except for some cavatation in a following sea. This occurs with the engines fully tilted down. Any uptrrim makes it much worse.
The engines are set at one bolt hole space higher than the lowest setting.
Will lowering the engines to the lowest position get rid of this annoying problem?? 8)

 

[RBallou]

Prop ventilation

Had this ventilation problem in a following sea when I repowered my 208 to a single 4-stroke. Initially, I had an aluminum prop. Changing to a stainless steel prop cured the problem. I use an Inertia prop on a 150 hp Verado 4-stroke engine. Maybe there is a useful thought here.

 

[ocnslr]

I would take a guess that you have the Yamaha "Black SS" props, in 13.75"x17".

Those are the props we had on our F150s after we repowered in Nov 2005.

Tried several alternatives, and now spinning PowerTech OFS3, 15.25"x16". We dropped one inch of pitch and increased diameter. More blade area in the water. Boat doesn't lose its "bite" when punching through a head sea, or running in a following sea.

Brian

 

[Patent Pending]

GW Props

I experienced some cavitation right after I bought the boat and decided to change the painted 13.75" x 17" SS props. I now have Yamaha Reliant series polished SS props on the boat. They perform much better but still cavitate, altho not as much.
Thanks for the thoughtful responses. 8)

 

[ocnslr]

Re: GW Props

I now have Yamaha Reliant series polished SS props on the boat. They perform much better but still cavitate, altho not as much. Thanks for the thoughtful responses. 8)

My post above was meant to highlight the difference between the 13.75" diameter Black SS props, and the 15.25" props we run now.

The Yamaha Reliance props are either 13.75" or 14.25", depending on pitch. So, not really much more blade area in the water. But certainly a lot prettier...

The 275 is a heavy boat, and props will cavitate (actually "ventilate") when they lose bite.

I only provided our solution. We no longer have that problem, and our 270 is a lot heavier than your 275 - if only because we have so much "stuff" on it...

Brian

 

[Patent Pending]

Props on F150's

Brian,
Thanks for the clarification. I hope I I don't have to go there.

Are your engines all the way down on the transom?

Chuck

 

[ocnslr]

Re: Props on F150's

Brian,
Thanks for the clarification. I hope I I don't have to go there.

Are your engines all the way down on the transom?

Chuck

No, there is a good inch or so gap between the top of the transom and the bottom of the engine mount.

And I think they could be one hole higher...