If you’re looking for a new sprocket, or a clutch for your KT100J or KT100S engine, it can be confusing to determine the size of your crankshaft. They all might look long, or they all might look short – but what is the easiest way to tell which one is which?
The easiest way to determine if your shaft is a long or short shaft is by measuring the nut on the end that holds the sprocket on.
A long shaft nut will be ~10mm ID (~10mm OD on the shaft thread)
A short shaft nut will be ~12mm ID (~12mm OD on the shaft thread)
