10 1/2 by 13 1/2 prop

[ilovevintage81]

I Have a 14 ft simiv aluminum boat with 40hp ski twinn im wondering about my prop what speep i can exspect im hearing my motor is big for boat is i get lower pitch like 10 what could i exspect or if i get like 15 i dont want to go super speed i may want a lower pitch any info would be great

 

[ilovevintage81]

Re: 10 1/2 by 13 1/2 prop

Another thing ive already filed it some cause of nicks so it may only b 10 now will that affect anything

 

[steelespike]

Re: 10 1/2 by 13 1/2 prop

I believe your prop is the standard size.Of course the final size would depend on the application.
A stock 40 on a reasonably fast light boat should approach speeds around 30+ range.
What year is the motor and what sort of load/total weight of the running package?
What pitch you need would depend on your present wot rpm and gps speed.
You would not go to a lower pitch unless your rpm indicated it.
Usually decreasing pitch will slow the boat and increase power like a lower gear in a car.
Again the prop change would depend on your present performance.

 

[ilovevintage81]

Re: 10 1/2 by 13 1/2 prop

Ok thanks maybe ill keep it the same cause im going to add like 150 pounds of wood to inside i just didnt want boat to be overpowered

 

[steelespike]

Re: 10 1/2 by 13 1/2 prop

Thats a good starting point, get us the rpm and gps speed when you get her on the water.
What is the actual length,beam and transom width.
If she is a small 14 I wouldn't be adding too much weight.

 

[ilovevintage81]

Re: 10 1/2 by 13 1/2 prop

16 inch transom 48 inch beam but gets to like 57in on top