Faster prop for Evinrude 30?

[juicegoose]

Recently picked up a used 16' jon boat. On it was a 1990 30 evinrude long shaft mated to a 10x13 prop. Estimated load was about 900 pounds accounting for the boat(plus gear), motor, and 2 men. After running it this weekend the rpm at WOT was around 5300-5500 at 26 miles per hour. The hole shot seemed to be more then enough with 2-3 people on board. What would you guys recommend as a next logical choice in prop if I wanted to get some more top end speed. I can afford to loose some hole shot I think. Ultimately I'd like to buy a stainless once i find the prop that seems to work the best for me.

Thanks Guys.

 

[gm280]

Re: Faster prop for Evinrude 30?

For starters, I’m impressed you are pushing your rig at that speed loaded how you mentioned with a 30 HP engine. How did you read that MPH speed, with a gauge or GPS? You could try a stronger pitched prop, but I think you are at the correct prop now. JMHO!

 

[juicegoose]

Re: Faster prop for Evinrude 30?

For starters, I?m impressed you are pushing your rig at that speed loaded how you mentioned with a 30 HP engine. How did you read that MPH speed, with a gauge or GPS? You could try a stronger pitched prop, but I think you are at the correct prop now. JMHO!

Glad I was able to impress. I clocked the speed with my GPS on my phone. Couple different times i measuered anywhere from 23-26 MPH.

I agree that the pitch of the prop seems right. Just wondering if there were options out there to put me at a higher speed with same rpm at the top end. I do have a 10x15 at the house that I can try.

 

[steelespike]

Re: Faster prop for Evinrude 30?

Actually at 26 mph and 5500 rpm your slip is indicated to be about 17% thats a little high but you are pushing a good load
so slip would be a little high.
I would be interested to see the results with the 15" prop.
It no doubt will be slower out of the hole and rpm will be about 400 less.
But a test would be interesting.
If your prop is 23 years old it could be older technology and it actually could be worn.
A new Solas Amita 13" pitch might reduce your slip and increase speed a little.
The Solas props do use state of the art "squeeze cast" technology.

 

[BonairII]

Re: Faster prop for Evinrude 30?

What is the optimum rpm range for your motor? Prop your motor to obtain the correct rpm rather than propping to get the most speed.

You def don't want to go up in pitch...and be lugging your motor.

 

[juicegoose]

Re: Faster prop for Evinrude 30?

What is the optimum rpm range for your motor? Prop your motor to obtain the correct rpm rather than propping to get the most speed.

You def don't want to go up in pitch...and be lugging your motor.

The props I'm testing with are all older prop but like I stated I'm hoping to get the best I can once i narrow down a pitch range.

according to evinrude the WOT range on that engine is 5200-5800 rpm. I agree I don't want to load down the engine to much but being a prop newb I was hoping i could find a prop that would give me a faster speed with the same rpm.

 

[jestor68]

Re: Faster prop for Evinrude 30?

My source (Marine Engine.COM) states 4500-5500 rpm for a WOT range.

I agree that a Solas aluminum 13 pitch would provide an improvement due to it's cutting edge design and casting process.

Only thing better would be a Solas New Saturn SS 13 pitch for $164.