I know it is an old question...what pitch prop is best?

[jgregory01]

I have a 1999 Johnson 50hp 2cyl 2stroke (J50pleea) pushing a 1999 Palm Beach White Cap 161. My prop is chewed up and I am in need of a new one. I am looking for an aluminum to replace it. I know there are all kinds of pitch for all kinds of use. I do not pull skis or tubes. I fish and pleasure cruise with the family.

My boat does not have a tachometer or an hour meter. I need to know what is the best general use prop that will give me good performance for my motor. I am not racing anyone so speed is not a priority. I just dont want the thing spinning into madness.

Any suggestions for a good all purpose pitch? I cannot find any numbers on my current prop. Thanks.

 

[HighTrim]

Re: I know it is an old question...what pitch prop is best?

It is very hard for us to properly answer that question with knowing what your current prop is, and what your WOT RPMS are with it.

An ideal prop will let your WOT RPMS fall within the reccomended range. Raising the pitch of your prop will decrease the WOT RPMS by about 200 RPMS, and decreasing the pitch of the prop will increase the WOT RPMS by about 200 RPMS.

Without knowing this, we are only guessing.

 

[jgregory01]

Re: I know it is an old question...what pitch prop is best?

I guess I should get a tach installed? Is there a plug and play on this kind of motor or does it require some kind of machining by a mechanic? Any balpark ideas on cost? Thanks.

 

[HighTrim]

Re: I know it is an old question...what pitch prop is best?

This is about the cheapest/simples solution

http://www.tinytach.com/tinytach/gasoline.php

 

[Silvertip]

Re: I know it is an old question...what pitch prop is best?

On that type and style of boat, and engine a dealer will generally install a 12-1/4 x 15P "cupped" prop. With a moderate load that should let the engine rev in the 5500 - 5800 rpm range. How do I know this? I've experimented with many props on a very similar setup with props that ranged from stainless 12-3/4 x 13P (way too little pitch) to 11-3/4 x 17P (cupped and uncupped). I always came back to 12-3/4 x 15 aluminum cupped.

 

[jgregory01]

Re: I know it is an old question...what pitch prop is best?

You mention a 12.25x15 but end with a 12.75x15. What would you suggest of those two? I want to make sure I understand your information. thank you

 

[steelespike]

Re: I know it is an old question...what pitch prop is best?

Diameter is secondary a props within with 15" pitch in any reasonable diameter will perform about the same.
If you check the prop charts for your motor here at oboats generally as the pitch goes up the diameter will go down
as pitch goes down diameter goes up.Just avoid extremes in diameter. If you read the helps on the prop store page it may help you understand
prop selection.Feel free to ask if you any questions. If you look near the base of the blades or under the prop nut
you should find numbers. Allway written diameter X pitch.You may be able to have your prop repaired you could then do a test run and get us your results and we may be able to tell if you are setup well.