Re: New Yamaha 4 stroke numbers
 

Ha Hattrick
Ya it does sound like the prop might be a little to big I would try the next size smaller to bring your rpm’s up a little bit.
FellowShip [img]/images/graemlins/cool.gif[/img]

Re: New Yamaha 4 stroke numbers
 

That engine should be running at least 5000rpm.

Re: New Yamaha 4 stroke numbers
 

Will going to a 13 3/4 make a difference or should I go all the way to a 13 inch diameter? What pitch should I go to?
Thanks for all your advice.

Re: New Yamaha 4 stroke numbers
 

Hatrick, IMHO I'ld leave the diameter at 14 just drop down to a 17 pitch. That should raise your RPM's up 3 to 4 hundred more. Are you running a SS prop or aluminum.

Re: New Yamaha 4 stroke numbers
 

The prop is aluminum. If the 17 pitch adds rpms on the high end what other effects will I see? Anything different at lower rpms?
Thanks.

Re: New Yamaha 4 stroke numbers
 

HT
Something seems wrong here, you should have 45+
mph with that motor. I would guess a 17" should turn
5500-5700 on that boat. You might want to get a
stainless stiletto/rapture prop and raise the motor

Re: New Yamaha 4 stroke numbers
 

Do you have a propeller dealer where you are. Not West Marine but a buisness that only deals in props? Ask them.
I went through 3 props on mine till I got the right one.
You can usually get them to lend you a prop. Remember if you ding it you bought it.
14X17 SS Rapture sounds about right. And like Seafari says you may need to jack it up.

Re: New Yamaha 4 stroke numbers
 

I would prefer to stay with aluminum even if I sacrifice some speed. I fish in shallow, rocky waters alot. I just want to be sure I am getting the correct rpms for the motor and the right speed for the right prop.

Re: New Yamaha 4 stroke numbers
 

I would try the 14X17 in aluminum then. It will still give 300 more RPM at WOT. And give you a better hole shot. But I would still consult a prop shop.