Hi all what should I do with my boat, my props are 15x32 4b and I am getting only 84 @ 6000 . My slip numbers are 17% my engines 250xs gear ratio 1.75 any advice .

slip number is really high, especially for 15in 4 blades. what height are your motors mounted?

Are u qualified to touch on this subject ?....

Seeing how he has the exact same boat, I would say he is more qualified than you!!! Why must you constantly take threads in the wrong direction! Can't you leave anything alone?
Sorry for the hijack. Carry on.

RIGHT ON!!

Your number is very high. Who's props are you running? I have seen slip numbers around 8 percent or less. 32's for 250's might be a little big also depending on set up and conditions. Eng height also a factor? Do you have jack plates? I have tried lots of props and found Dewalds work best. They were 3mph faster using a 4 blade versus the same pitch mercury racing 3 blade. I can give his number if you like?

Gonna need more info, Motors bolted to the transom or on jacks?

ho again the motors bolted to a 6" TH manual jack. when i was running my other 3Blads prop which was 15X31 i was getting 90-91 mph my slip around 10%. at the same hight. i switched to those 4Blads prop bigger size 15X32 and i am getting 17% slip and speed went down to 84 MPH at the same 6000 RPM.

If those are merc 4 blade cleavers, I have never seen them run as well as the 3 blades. Have had really good luck with the Dewalds as well on a 28 with 300XS's. You may want to raise and lower them some if you are set on keeping these props and see what your speed and slip does.

Lose the merc 4 blades. I have tried them on two outboard cats and also a 28 skater. Good midrange and punch but no top end at all. Three blade Merc lab cleavers are the best. 15x32 might be prop.