Mercury 50hp 2 stroke wont rev completely out in gear

I have what i think is a early 90s mercury 50hp 3cylinder 2 stroke. Idles perfect and runs great to probably half throttle then thats all it has. It wont go past half throttle. I cleaned the carbs, the oil injection isnt working properly. so ive been mixing the fuel 50:1 the oil injection isnt bypassed yet because i havent been able to find the correct kit. The spark plugs look oil fouled even though it doesnt really smoke running. It free revs in netrual to full rpm but all the threads i read just didnt seem to fit my exact problem. If anyone could give me some ideas on what to check it would be greatly appreciated im tired of being stuck going 8mph makes for a long trip lol. Im leaning towards the oil injection and mixed fuel causing my problems but im unsure since i cant find the block off kit. (Will get model number and compression numbers after work) thanks you in advance any help would be greatly appreciated!

heres a photo of the motor

Well heres the compression test numbers i ended up with first cylinder was 78psi 2nd was 78psi also and 3rd was 72psi, test was done at full throttle. Also here here is my serial number odo69462. Checked spark its getting a nice blue spark on all cylinders so not sure where to go from here.

How do you know oil injection is not working properly? These rarely fail on this model unless severely overheated. Try a different compression tester as those numbers are way low...Is this motor "new" to you? Those motors are prone to have sleeves slip and turn if lugged, what was RPM as I see its on a toon.

The oil injection level hasnt moved really in over 12 gallons of fuel so got concerned is why i started premixing. Motors new to me this year, if i had to guess rpms i would say 3000ish at full throttle as there's no rpm gauge. Its on a 1987 20ft pontoon. Ill have to get a different compression gauge and try again. As far as i know it hasnt been overheated but previous owner spoke very little english so i am unsure.

Tried another compression gauge top cylinder was 109psi middle was 109psi bottom was 105psi so still not great but a lot better then 70. I took the carbs apart nothing looked to be clogged but i gave them a touch up anyway. Not sure what else to try before trying to take it out on the water this weekend.

Having the exact same issue with my 02 60hp 2 stroke. I haven’t been able to isolate the concern either. Carbs were redone last season, this year it’s had new plugs, fuel filter, rebuilt fuel pump, primer bulb and line, and replaced what I thought was a weak coil. Still no change after all of that. Replacing the fuel line from the motor connection to the oiling system today (the only piece of fuel system that hasn’t been replaced), after that going to try and throw an electric pump on it and see if that helps. I’ll follow up when I’m done