Howdy folks just opened the service manual to discover last service 1997javascript:emoticonp('')...maybe due an oil change then.... fortunately only 2500 miles ago never the less...oil petrolly smelling but no sludge or bits

Had assumed irregular clacking noise from "engine" whilst running (idle, clutch in or out, any or no gear) was maybe down to low oil at the top of the engine, but seems more like left side of the crankcase- Loose cam chain/ tensioner or similar? Is that a no ride issue? Whats it like as a DIY job?

The bikes only done 2,500 miles in 13 years....bloody hell

If I were you I would change oil and filter, Motul 10w40 is what I use. Its a doddle to do on the CB, just make sure its warmed up as it'll help drain the oil out better.

Could do with a service anyway so try that and see how you get on