Hi, well Margay rims are rare.. you will need to keep your eyes peeled on ebay and such I'm afraid..
and expect to spend some money
we talk iame KPV's right? (trailing fins on the cylinder, piston port 100cc?)
in that case
KPV top end is available from cometkartsales still
https://cometkartsales.com/KPV-Top-End-Parts-and-Electrical/
IDK the MBA chassis .. but chances are it's just too stiff for a slowly driving lightweight kid in the seat.
could you post a pic of the kart (steering would be great as well as rear end)
what I'd try first is to remove the hopefully detachable rear crossbar.
(that should already allow for more flex in the rear and thus a lifting wheel..
if not the next smaller axle diameter (for european axles)
or the next softer (for american axles)
And if the steering is still sub-par, then I'm guessing someone might have swapped
the spindles and affected the steering geometry
So some ackermann correction might be due (usually reloacting the tie rod ends and proper alignement is all that's needed)
And once that's checked as well, the ONLY thing left would be to teach the kid how to take a corner on a kart (with speed!) the c51 isn't the snappiest engine out there of course, but should still suffice for a inner wheel lift.
sidenote: I was told that some kids have an easier time getting a feel for it with skinnier wheels,
so maybe narrowing the wheels on the rear might help
(so the inner wheel is more likely to slip in corners if it still has road contact)
'sid
