Need help with which prop I should use? and max rpm on a johnson please help!

[johnson426]

Re: Need help with which prop I should use? and max rpm on a johnson please help!

Is that where I should be or be going higher in speed ?

 

[trendsetter240]

Re: Need help with which prop I should use? and max rpm on a johnson please help!

Is that where I should be or be going higher in speed ?

That's about right. Your prop slip is around 17% right now. Sounds like the boat is just a little too heavy for that motor when you are fully loaded. A 115hp would be a lot better.

If you go with a 13p Solas Amita 4 blade aluminium you will have much better holeshot and be able to stay on a plane at lower speeds. I'm thinking you should be able to hit 5500RPM and have speed remain about the same but the engine will not be struggling so much.

 

[cougar1985]

Re: Need help with which prop I should use? and max rpm on a johnson please help!

i had a 17 ft mfg gypsystar that was pretty waterlogged and i had a 82 90 evinrude on her.ran a 17p 4 blade solas amita and still would hit 5400 or so.the boat when i took her to the dump weighed 2070!she would do the mid 30,s all day but to get the best preformance out of it i also installed nauticus trim tabs ,work fantastic i might add.tilting in all the way seems not good to me ,mine if i was to look at it as a nontrim motor which it was would of been about 3rd hole from the bottom.if you only hitting 5200 with you motor something isnt right and im guessing its because your tiltig all the way in and you might need trim tabs to help also.strictly a quess i might add!