99 250 0x66 low compression

[STUGOTS13]

I have a 99 ox66 loses power at full throttle.all test for fuel system and ignition are good.compression test:top 2 cylanders 75 psi and other is 80 psi.all others were exactly 1220 psi.could i have bad reed valves in those cylanders??????what and how do i proceed testing???

[boats.net]

Reed valve wont cause low compression, probably have piston, cylinder damage.