New boat owner!! need a new prop!!

[scubarob56]

i just bought /received a new prop from iboats. quicksilver, 12 3/4, 21 pitch, 3rh. i used the iboats outboard propeller search and that's what they came up with. this is my first boat! i know how to drive them, but that's about the extent of my knowledge! my neighbor who has had boats all his life thinks it's the wrong prop. i looked at the existing prop and it is stamped 14 1/4 x 23! i was told that for my boat,(1986 Ranger 330V) would do better with a 21 pitch prop. my question or begging for help is: what prop do i need? what is the correct size? again, i really, really need some help here. i desperately need a new prop and i want to make sure i get the correct one!!!!! so, please anyone out there who can help would be greatly appreciated!!!!! i don't think i'm supposed to put my email address here, but if there is any way i can get an answer quickly, please, please help!!!!

 

[Stingray185GXi]

It's not possible to give you a good answer without knowing info like what motor it has, how it performs (WOT speed, WOT RPM, holeshot, and handling), and how you plan to use it. Two different people with the exact same boat could be very happy with very different props simply because they use the boat differently and are looking for different things from their prop.

 

[Tail_Gunner]

ESSENTIAL DATA REQUIRED
When posting a question about propellers, you cannot get a reasonable answer unless you provide the following information in your post: Items 1-4 are essential for meaningful response to most questions.
1) Performance issue you are trying to correct.
2) Current prop manufacturer, model, aluminum or stainless as a minimum.
3) Current prop diameter and pitch (required).
4) Wide open throttle RPM and speed with an average load (very helpful)
5) Engine/drive make, model, year, and HP
6) Boat make model, year, length and weight

The below link would be a much more thorough list of data to provide if you're looking for detailed performance numbers,
http://forums.iboats.com/prop-questi...ml#post2336620

Frustrating but it works almost every time.

 

[steelespike]

Good morning and welcome.
What size motor? The 12 3/4 X 21 may not be intended for your motor may be intended for a smaller motor.
Your 14 1/4 X 23 is intended for a larger motor.Something like a 4.3 I/O or big outboard.
I wouldn't install the 12 3/4 X 21 until we establish what motor and hopefully a test run with the 23.
If the 23 is in reasonable shape you could do a lightly loaded test run for wot rpm and gps speed.
We can tell from that how your setup works.Selecting a prop is like trying to select a single gear in the car to do everything.
It will likely be a compromise. Your 23 is more like a high gear in a car your 21 is closer to a lower gear.
The idea is to select a prop that satisfies your needs while allowing the motor to perform well within its wot rpm rating

 

[scubarob56]

i have a 1986 johnson 120 hp,model number j120tlcdc. i want to use the boat for fishing and occasionally pulling the grandkids on a tube

 

[scubarob56]

the boat that it is on is a 1986 Ranger 330V

 

[Chris1956]

That 21P prop is likely close enough to try. You will want to get into the high end of your max recommended RPM range, with a light load.

 

[steelespike]

Agreed the 21 is a good starting point for a lightly loaded wot (wide open throttle) test run. We need your max rpm and gps speed.