Mercury 50hp not loading in gear

[baxter08]

Hey everyone,
I have a 2003 Mercury 50hp 2 stroke (serial# 0T926330) on a 16ft flats boat that has issues reving under load in forward.
Sometimes will get up on plane and go(no clear corrilation from cold or hot), but they bogs down and wont go past a certain rpm. Will rev in nuetral and reverse fine, just wont load up in forward. cleaned the carbs new fuel filters, pump rebuild, disconnected yellow an black wire from rev limiter box, checked all sparks right after run...nothing works. Rpm gauge on boat not working so cant get a definitive rpm.

Any ideas?*

[Merc 2.5]

Fuel fire and compression. Need spark gap tester. check compression b4 u do nething else

[baxter08]

Sorry forgot to mention I had done a compression test, dont recall exact numbers but searched to see they were all good, consistent for all 3 cylinders. Changed spark plugs to factory quicksilver ones.

[Motv18]

What type prop hub, if it’s rubber check to see if it’s spun.