I dunno man, ever GD gator I've had has been a rickety rattle trap. If all I had on my gators was a belt that slapped at idle, I'd call that a win.
Btw….they will do that. It is what it is. The belt hangs loose, if your clutch is working properly. I havnt seen a gator whose clutch works properly unless it has less than 50 hours on it. I rebuilt all my gator clutches. It doesn't take long to get flat spots on the rollers.
The M Gator is pretty much the same as any other gator except with a different shade of green, a hood rack, and a slightly up-rated motor. I don't think it's a different motor than any other gator but it's rating is different for contract purposes. Otherwise, same features. I don't know that you can really correct that. A smaller belt with cause the trans to spin possibly making it hard to shift from neutral to f or r.
I have these in various vintages on our ranch and while they all run like scalded apes, the "what the **** is that noise?!" Is high. They ride like covered wagons and are noisy. It's part of its charm. They are built to get a job done not impress your bros while drinking white claw and jamming out to Luke Bryan.