Carl,

Wow. A 15' boat and a 115 hanging on the back running 47 mph!

Got any rubber plugs at the base of your prop? Look up prop ventilation
and see if you think that will help you. Google the group for "prop and
vent" or "prop and venting" and you should get some results from a few
discussions a while back. That might be the simple, and free, solution
you want.

Dan


Carl Harrison wrote:

Hi,

I have just bought an Osprey 15 foot boat manufactured in Zimbabwe. It
has a Yamaha 115HP outboard with a Laser II 13.5" X 22" prop. The boat
will reach 47 MPH quite easily with the engine running at 4200 RPM but
according to the engines manual the engine can rev at 4500 - 5500 RPM.

Am I correct in thinking that replacing the prop with a 19" pitch one
will raise the revs to 4800 RPM and give the boat a little more
acceleration?

Are there any possible problems in reducing the pitch?

All advice greatly appreciated.

Thanks