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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.
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...........
If i remember corectly it runs around 4500-4700 rpm i may just have to double check
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.
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.
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?
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.
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.
I would drop one pitch going to stainless,
they don't have ad much slip as an aluminum prop
I agree with Cray and clfarms1 and stay with the same size prop. whether Aluminum or Stainless.
Thanks again I think I'm gonna start looking for a 10x13 ss