2007 Yamaha F150 M18 Prop

[Cman1216]

Last year I purchased a 2008 21 FT Century Inshore with a new 2007 Yamaha F150 4-Stroke. I should have but pay any attention to the Prop until I loaded the boat down with equipment and about three adults (large). Now I noticed that I can olny acheive about 5300 RPM. Top speed is about 42 MPH. It takes a bit to get out of the hole. I just went and looked at my SS Prop to try and get the size and pitch but the only thing stamp anywhere on the prop is M 18. Does this sound familer to anyone? Is it even a yamaha prop? I think it must be the wrong size.

 

[water wiggle]

Re: 2007 Yamaha F150 M18 Prop

You may need to go down some in pitch. I do know that the m18 is a Yamaha prop. You may want to step down to a 17 pitch as the m18 is an 18 pitch. Check mfgs max rpm at wot and pitch down from there.

 

[Silvertip]

Re: 2007 Yamaha F150 M18 Prop

Dropping to a 17P would "theoretically" raise RPM to about 5700 with the same load and help getting out of the hole but you would need to be careful when running with a light load as engine speed may exceed the manufacturers WOT rpm. See if your prop dealer will let you try before you buy. Just be a sport and buy from them after your testing is complete.