Cavitation Plate

[Dman]

I recently bought a 1993 Yamaha 30 with a short shaft. My boat has a 15 inch transom, but I have noticed that the cavitation plate is about 1" or so below the bottom of the boat. Is this ok or should be corrected? It's a V-bottom, 14 ft. If it should be fixed, how do I go about doing it? <br />Thanks.<br />D

 

[FlyBoyMark]

Re: Cavitation Plate

This is the NORMAL location of the cavitation plate, about 1" below the keel. raising it is for generaly high performance applications and requires a different type of prop that is designed to run partialy out of the water at speed. In some instances for "push" motor applications it could be even set deeper. You can jack the motor up or rebolt it higher if you can attain speeds above 35 mph with the present configuration..in some cases at this low range you might gain one or two mph by doing this. You might also start to cavitate depending on the hull design. In any event, you should not go higher than 1' above the bottom or keel unless you have the ability to go faster than 35 mph to begin with. If you can get into the real high speed ranges (50-70 mph) raising the motor till the prop runs out of the water with a "cupped" prop could get you 5 mph or more. This generaly takes exprimentation and time to do and trying different props for you application.<br /> Hope this helps...<br />FlyBoyMark

 

[Dman]

Re: Cavitation Plate

Thanks for the message. I was just curious becasue of all the messages about how important motor place was.<br />Thanks again.<br />Dman<br /> http://myweb.ecomplanet.com/GLEA8449/