prop recommendations

[brownie]

I have a 92 lowe 170 with a 25 johnson this is my first and only boat and dont know much about them. My question is how do i know or find out what prop i need it currently has an aluminum one that looks pretty bad. Thanks in advance for the help and input.

[midcarolina]

You need to know what the rated wot rpm is for your motor.... you need a tach and have the boat with a normal load, run the boat with existing prop note wot rpm, only then can you make an educated decision on prop needed...........

[brownie]

If i remember corectly it runs around 4500-4700 rpm i may just have to double check

[Cray]

First look at outside of hub and should have some numbers stamped in it similar to this 11 X 13. That will give you the pitch and diameter. That should be a good starting point. If you are happy with performance stay with that in aluminum. You could go stainless but not gain a lot performance wise on that setup. Stainless will give you better wear.

[brownie]

I looked at the prop that i currently have on it says 10x13 now im looking to find out what rpm it should run at full throttle. As for how well it performs i cant be real sure its about the only boat ive driven so dont really know what to expect. i can get 24-25 mph out of it.

[Cray]

I would say that's pretty good for a boat that size with a 25. With stainless and a little adjusting you might coax a couple of more out of it. Assuming your running on power restricted lakes. Do you have power trim?

[clfarms1]

if your getting 25 out of it, go with the same pitch in ss. thats about what I did with my merc. with the same prop size.

[brownie]

Good deal I was thinking that seemed low on rpm. but I don't know. I don't have power trim but I sure wish I did thanks for everyone's help and input. Now time to start shopping.

[midcarolina]

I would drop one pitch going to stainless,
they don't have ad much slip as an aluminum prop

[dfar]

I agree with Cray and clfarms1 and stay with the same size prop. whether Aluminum or Stainless.