Drr 90 tranny/clutch problem

Hello i really need some help. Just got this quad running excellent and super fast and guy who built is supposed to be very good and there sup to compete with 2 fast quads. This thing is the fastest one I've been on so far but son rode 3 times and it feels like clutches are gone or tranny is out. When you gas it it jumps like belts loose and gears are grinding but not getting grinding noise it's like a deep hard vibration that feels like it's comin apart. Belts brand new with the I've range kit and 1 ride made it where I can take off by hand. Very weird and has me lost. Can someone please help and sorry about the book I'm writing just trying to explain it right. Thank you

only real way to know is too disassemble and inspect
we run a 2fast
they are hi maintenance

Ok I'll get tore down and see if I can see again. Last time everything looked good and just so happened to grab belt and pull off but ended up that's not prob anyways. It's gotta be deeper. Thanks for info, I had no clue they were this high maintenance.

This may sound crazy but check sprockets, carrier, carrier bearings, etc. It sounds like the chain is skipping a gear. Chain tensioner is OK?

That's exactly the noise and feel. I will check that cause I checked chain and seemed tight but never checked how tight carrier and sprocket was. He just let it sit while I finished his rt and wouldn't you know it chain popped off it yest. Thanks alot and I'll let you know. Also when I'm revin up its like the engine is touring or slightly twisting so not sure why. Thanks

Is the clutch staying engaged? I thought I had a chain/Tranny issue but it was the clutch not staying engaged. I had to add some weights and change my shoe spring.

Check your motor mounts.

That is one thing that's moving. When I gas it it twists some but everything is tight but the rod itself looks to skinny. Now one on our rt 70 has the high mounts and thicker and very tight. Ant believe how fast these things loosin up. . I'm gonna try to get home early tomorrow to try all this stuff and I really appreciate all the help everyone has given me. . Thanks and I'll let ya know