I'm new to 2-strokes and although I've ridden a MC21 briefly, I don't know too much about NSRs. However there is a MC18 in my area that I'm interested in picking up. What should I look out for?

I've owned several bikes, so I know what to look for in terms of fork seals, suspension, tires, chain/sprocket etc.

Obviously I won't be listening for valve chatter, but what specifically should I look for?

What are the best tells that pistons/rings and/or crankshaft are soon due for replacement?

Thanks

Curifor