Yamaha 50 Prop Pitch RPM Question

[jeep187]

I have a 18' Pontoon with a 2006 Yamaha 50 2 stroke on it. The RPM range per Yamaha is 4500 - 5500 WOT. I was running a 12 1/4 x 9 Prop with 3 people and gear at 5500 rpm WOT. I then switched to a Turning Point Prop 12 x 10.5 still 3 people and same gear and im running 4900 RPM WOT.

Is this fine or should i switch back?

 

[steelespike]

Re: Yamaha 50 Prop Pitch RPM Question

You should be running closer to the 5,500 rpm figure.
Even though you are within rpm range you are lugging the motor,
especially on a pontoon.
What model Turning point?
If a Hustler it is a really agressive prop thus would result in a larger drop in rpm.
than typical.Also changing brands can make results difficult to predict.
More importantly what speed with each prop?

 

[jeep187]

Re: Yamaha 50 Prop Pitch RPM Question

yes it is the turning point hustler. I was doing w the 12.5 x 9 between 5400-5500 rpms 15.2 mph

now with the 12 x 10.5 between 4900-4950 rpms @ 18.2 - 19 mph

 

[steelespike]

Re: Yamaha 50 Prop Pitch RPM Question

If the Hustler worked well for you try it in a 9".Should get back most of your rpm
and still be close to 18 mph.
It appears a 9" Hustler may not be available.You may be able to have a prop shop remove some pitch or cup.