Cavatation Issue......

Below is a picture of the boat I put together for the summer. ...but there is a cavatation issue at times. My thought was a "cavatation" plate between the sponsons aprox 8" wide,forcing the watwer back further to the outboard.......any Ideas?????............Dave

 

Vinke me mate, nice looking boat, but I understand you have a problem, to help you out buddy, just drop the boat around to my place and I'll look after it for you problem solved.

Can I ask you a question or two?

What are the two wheels for just under the transom on the trailer and what is thge cable that is hanging down that comes out of the transom and dangles behind the boat?

I used to help a friend of mine get his boat ready for racing and we'd move the motor angle and check the speeds over a set distance to find the position to give the best speed.

I am not an expert on outboards, or anything else for that matter, but you motor bracket seems to be on a hell of an angle, maybe it's an optical illussion from the photo.

But I guess someone with some knowledge on the matter will advise you.

I've just come home from shopping having a couple glasses of red, and relaxing for the rest of the night, giving useless advice to people with nice boats.

See ya

Poida

 

Cavitation issue, or ventilation issue? It's not quite the same thing.... cavitation means the pressure on the back of the prop blade drops so low that bubbles of water vapour form on the prop blade, ventilation means the prop is sucking in air from the surface. I think your problem is the latter. Does lowering the motor height have any effect? Your motor is set back a fair distance from the actual transom, which makes it a bit harder to find the right height.... the plate you describe may help but I would start with engine height and trim if I were you.

 

prop ventilation problem

Hey Vinke, I looked at the pictures of your boat, nice boat, but I couldn't tell if it was a catamaran or not. If it's a cat I'd be willing to bet that the problem is air in the water flowing between the two hulls. A lot of cats run an engine behind each hull to avoid this problem. How about a picture directly from the stern at bottom level? Regards rusty