Alright all I need some help

I have a 1996 Polaris Xplorer 400L, i know I know I’ve heard it all, it’s a 2 stroke, they suck, get rid of it, on and on and on. But this thing has been around for awhile and has always been a pretty good machine for the acreage. It’s not without its problems but the oil injection still works, it’s in good shape, and it still starts up with 1 touch of the button. It just doesn’t move anymore.

here is what happened

Quad worked great last year, sat for the winter. This spring when I pulled it out to use it to harrow some pastures, on the second day it started to smoke after running for 20 minutes. Engine wasn’t hot and the smoke wasn’t coming out of the exhaust. Clutch cover was really hot so I pulled it off and there was chunks of rubber and the belt was glazed, I figured easy enough I smoked a belt.
Grabbed a new belt and figured I’d change the transmission oil and counter balance oil at the same time.
After all that the unit will start up no problem, idle no problem but when I press the throttle it won’t go over what I would say 50-60% rev and the quad wont move.
So I went to the next steps, soaked the carb (little bit of algae in the bowl) put a new carb kit in, new spark plug, new air filter, new fuel filter. Can adjust the carb so it coughs and sputters, can adjust it so it starts but doesn’t idle and when I set it up how it normally is, clip on 3rd position, air screw about 2 turns out it starts and idles great but same thing only 50-60% throttle and quad won’t move.
Cold compression test is 120psi, not loosing any coolant, can sit an idle for an hour and get hot enough to kick the fan on, but just doesn’t have enough power to move the machine.

I don’t have the tools to do a leak down test but my next thought is crank seals.
Anything I have missed or can check before I just change the crank seals?

 

If the quad won't move at 50% revs something has seized in the transmission. However, if it won't rev enough for the centrifugal clutch to engage, that is just over idle speed, and could be a blocked exhaust, but that is nowhere near 50% revs.