Advise needed.

[Jperkins27]

I have a 2000 190 superpro procraft with a 175 efi. It has a 24P 4 blade and I can only get in the mid 50s gps by myself with median load. The boat has a hydro jacker 10 jack plate but it currently does not work. I can only turn about 5000 rps  I have tried a 3 blade 25P which bumped up rpms to about 5400 and bumped up the speed to about 56. I currently am testing a 27 P which bumped to about 5200 and 58 mph. With 2 people and tournament load i can only get about 52 mph  I have read that this boat and motor should run at least mid to upper sixties. Does anyone have any suggestions as to what may be causing the low rps and speed. Any advice would be greatly appreciated. Thanks in advance.

[SNAGGER51]

1) Does your power trim work properly? If it trims slowly, it could be low in fluid. This can restrict trimming all the way. This will decrease your RPM's...just a thought.

2) Make sure your throttle cable works properly. It could be adjusted to get more throttle.

Hope it is this easy...good luck.

I agree your RPM's & speed do seem low. Should be low 60's.

P.S. Oops! I forgot about that jack plate...that could also be the answer.