what prop size can i use besides my stock one? please help

[jose5050]

i have a 17ft wahoo with a yamaha 50hp with a prop size 11 1/4x14-G
RPMs are fine at WOT they are at about 5300 and geting appox 26mph.
Do you think there is any other prop that i can put to improve performance???

[jose5050]

bump need help

[99yam40]

Performance Bulletin Home
Look at his site and put in your info to see what prop they ran and the performance they got on a boat like yours and compare to yours.If it is way off then you may have a motor or set up problem
Just make sure what you run allows the motor to get to the upper part of the RPM rating of your motor so that you do not lug the motor and end up hurting it

[jose5050]

well its running fine like it should be i just wanted to know what you think about maybe geting a diff pitch or size to get a little more mph out of it?

[99yam40]

like I said check out that site and see what a boat like yours does. My C40 will turn 5500RPM and do 32 mph gps, but it is on a 16 SV Xpress and not loaded very much

[Tucker]

I've always wondered if the prop advertising hoop-ha you read is valid. If the the stock prop makes the engine turn at the high range of the RPM spec, what is the advantage of a different prop?

[Reel Kahuna]

... what is the advantage of a different prop?

Having the right prop is like having the right gear ratio on a vehicle. Your boat's motor will either be lugging (straining) or over revving with the wrong pitch.
Here's a great step by step instructions that I found on the internet that explains how to determine the proper pitch.

Some people wish their boats had a higher top speed, some wish their boats would accelerate faster and some wish their boats would go as fast as "the book says it should," referring to their boat's manual. Often, this kind of performance change comes from finding the prop with the right pitch--how far forward, in inches, each revolution of the prop moves your boat. Finding the right prop means some research, putting your boat in the water and go at wide open throttle (WOT).

· Look in your boat owner's manual or your engine manual and find the maximum recommended number of revolutions per minute (RPM) for your motor. Your boat should be at or very near the maximum RPM when your throttle is wide open--called "wide open throttle" or WOT.

· Take your boat out on the water and push your throttle as far forward as possible--to WOT--and watch your tachometer. If your tachometer rises to the maximum recommended RPM, then levels off, you have the right prop on your boat.

· Keep an eye on your tachometer. If the RPM rises and tries to exceed the maximum recommended RPM at WOT, pull your throttle back just enough that you don't exceed the maximum recommended RPM. If you are unable to reach maximum RPM at WOT, take note of the RPM you were able to reach at WOT.

· Increase the pitch of your propeller until you do not exceed maximum RPM at WOT. For optimum performance, reducing your prop's pitch by 2 inches--from a pitch of 18 inches to a pitch of 16 inches, for example--results in a drop of 200 to 400 RPM in engine speed

· Reduce the pitch of your propeller if you do not achieve the maximum recommended RPM at WOT. Again, a change of 2 inches results in a change of about 200 to 400 RPM.

[rodbolt17]

a good example of why I dont post on some threads.
are you using your trim, if applicable, correctly?
NO such thing as a STOCK prop.
propellor selection is done at the pre delivery inspection.
dont care that a prop came in the box.
when that engine left japan in a box the enginneers had no idea what that engine was going to be bolted on.
could be a 30ft barge could be a 14ft tinny.
they dont know.
but a 50 on a 17ft wahoo is a tad underpowered at best.
you may try playing with engine trim and prop cupping.
I doubt your gonna get much more.

[Reel Insane]

I must agree with rodbolt on this one. According to iboats your Wahoo is about 890 pounds empty (meaning no gas or equipment on board) and the boat is rated for a max horsepower of 100 hp. Your boat really should be at the upper end of that spec in my opinion. By the time you add gas, equipment, and people you will be pushing that engine to the max efficiency. A 75 hp or 90 hp would be ideal. If you are truly running 5300 rpm and 26mph your engine performance is right in line with where it should be.

All the specs I got was from an independent site. I am not sure if they are accurate.

Reel Insane