need suggestions

qwackhead

Cadet
Joined
Dec 1, 2009
Messages
26
first I have a 15foot long by 48inch wide aluminun john boat it has a 2001 johnson 30hp with cmc tilt and trim I have a 10 1/4 X 13pitch prop i can hit the rev limiter with two people so i need to go up in prop about how much speed will i gain by doing this im at around 31 now and what prop do you recomend i have a solas and not real impressed.
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: need suggestions

What is the setting for the rev limiter?You need a tach before making any prop change.Making a guess of your rpm could lead to poor operation/performance and economy.Also could cause premature engine problems.Check out the tiny tach.
 

qwackhead

Cadet
Joined
Dec 1, 2009
Messages
26
Re: need suggestions

the rev limiter is set at 6200 its hard to tell when i get close thats about where the tach is
 

steelespike

Supreme Mariner
Joined
Apr 26, 2002
Messages
19,069
Re: need suggestions

Is the motor a 2 or 4 stroke?Your speed seems about right Though at 6,200 it would seem a little more should be there.Some times A jon will run pretty flat so speed may be down a little.
I'm a little outside of the real prop experts.When changing prop style and brand
you introduce more variables into an allready difficult equation.I'm inclined to lean toward lower pitch numbers because if you end up over reving you can still run it by throttling back a little if you end up over propped you shouldn't run it.
I like the Turning point Rascal for smaller motors.This is an agressive prop that in my opinion may lower your rpm a little in the same pitch.Generally the Turning points improve performance across the band.Deliver close to SS performance.
They are pretty reasonable so you wouldn't go to the poore house if you had to buy a second prop.If you go to the turning point site you may be able to put in your numbers.I feel the 13 is really close and I wouldn't go any higher than a 14.
I think the Rascal will improve your top end but it could be anywhere from a few tenths to a couple of mph.It should also allow higher trim and vertical height.
 
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