Problem getting up on plane

"I have a 90 HP Force on a 94

"I have a 90 HP Force on a 94 Proline 17 foot center console. 13 1/2 X 17 pitch prop. Only getting 4500 WOT when I should be getting between 5000 and 5500 WOT, Checked the throttle adjustments and everything looks good. Tried a 13 3/4 X 15 prop and did not get the 300-400 additional RPM I was suppose to get. Changed the lower unit lubricant,( needed it badly) What else could be wrong that is causing such poor performance gewtting up on plane. My next step is possibly a set of manual trim tabs, or maybe a wing on the outboard. anyone have any suggestions?}"

"Should be on the plane before

"Should be on the plane before WOT.....is your tilt/trim adjusted correctly? How about weight distribution on board, tried moving the fuel tank forwards? Permatrim may be a better way to go than trim tabs."

"I tried the trim all differen

"I tried the trim all different ways. no difference. Cant move the fuel tank, at least not that I know of, its built in. I looked at the permatrim. I think Im going to try that. Appreciate the advise. took it out abain this morning, getting aprox 4600 RPm @ WOT, My son and I were the only ones on. looking at an additional 380 lbs"

Have you done a compression te

Have you done a compression test and checked the ign timing??

"The compression is all good.

"The compression is all good. I have not checked the timing yet. Ill try that this weekend.. Thanks again..I also had a clogged fuel filter, so I suspect some dirt in the carbs. I plan on a carb rebuild this winter."