The drivetrain is consisted of:
Drive pully. Connected straight to the engine.
Belt. The belt that connects the drive pully and the driven pully
Driven pully. Which is behind the clutch.
Centrifical clutch. Which means, when the spree idles it doesnt move the rear wheel, but when the driven pully starts spinning faster it grabs the clutch and starts spinning the wheel.

This goes on behind the left crankcase cover, also known as the transfer case. this is where the kickstart is/would be. You should check the drive belt every 1500 miles or so.

Check the drivebelt for cracks, separation or abnormal or excessive wear. Replace it if necisarry.
The service limit for the width is 10.5mm (0.41 in) if it is 10.5mm (0.41 in) or smaller, replace.