odes engine with i'm guessing odes drivetrain, low speed issues

[demaris]

i've purchased an 2014 applestone 800cc side x side.  what's an applestone, right!  found that out.  nearest applestone parts, new zealand. great.

it actually has an odes 800cc engine which helps.  and a cvt belt drive.  i suspect that the drivetrain is common to other vehicles but i don't know which.

my problem is that when starting off in high fwd, the right rear tire jumps somewhat violently and the transmission chatters a bit.  all smooths out when it gets rolling 5 to 10 mph.  what i'm trying to find out is if this is normal, or an issue with the differential, or a transmission issue, or the cvt?  bad gear meshing, or maybe an old belt that has been hardened?  is there a clutch in the design, not smoothly engaging?  my experience with variable drives like this dates back 40 years to the reeves variable drives that used be attached to ac motors by reliance motors inc. and others.  their design didn't allow it to idle while the motor was running and was intended to provide variable output while the motor turned at a constant speed.

any ideas before i start tearing things apart?