Prop selection for new E-Tech 150

[aquaman88]

got my new motor yesterday and everything went great, ran perfect got it to 39.5mph (gps) @ 5000rpm, I have a loner prop from the dealership on there right now that is a SS 15x17, I am hoping to get around 5500-5800rpm, what do you guys think i should go with?

 

[schematic]

Re: Prop selection for new E-Tech 150

I would try a 13p aluminum.

 

[steelespike]

Re: Prop selection for new E-Tech 150

Is that a deck boat or pontoon What size/weight what kind of a load?It seems to me based on the appearance of your boat a 17 should
deliver more than 5000 rpm.If you lookup the 150 Etec tests on the Evinrude site you should find similar boats.

 

[aquaman88]

Re: Prop selection for new E-Tech 150

there are 3 fiberglass pontoons underneath but they are shaped like mini v hulls, i looked at evinrude.com and saw most of the guys (tri toon pontoon boats and v-hull deckboats) were using 14.75x16,and getting 5500-5700. i believe the dryweight for the boat is around 2500lbs, the oat is 21ft long

 

[steelespike]

Re: Prop selection for new E-Tech 150

Are your figures with a light load?
Going to a 13" prop for 5800 seems extreme.
And your numbers at 5000 are right on.
Don't assume because its a new install that everything is right.
Your motor may be too low, the throttle may not be opening all the away.
Is the bottom clean and smooth no peeling paint.
Speed at 5800 with a 13" calculates to 34 mph.
Hole shot would likely be amazing.

 

[aquaman88]

Re: Prop selection for new E-Tech 150

the bottom does need to be sanded down and painted again, I believe the height is dead on, with the motor trimmed up slightly you can see the cavitation plate and there is no cavitation/over rev. the dealership suggested trying a 15x15, so they ordered me one and it will hopefully be in for me to test it out this weekend. I did test it under a light load, 2 people, full tank of gas, and 2 pieces of furniture, this week I will be adding approx 400lbs of new furniture. as it is the hole shot was amazing, seems like I was up on plane in 3 seconds.

 

[steelespike]

Re: Prop selection for new E-Tech 150

The poor paint can slow you down, sometimes just painting will slow a boat.
Looks like you will be needing the 15 at least with 400 lbs of added weight.
Not a hard and fast rule but usually an amazing hole shot and low rpm don't go together.