two stroke duke??!!!
 

my 91 900ss has started drinking a bit oil - (300ml in 500 miles), but she has done 40k and i know the only real cure is new rings etc, but do i do it now or wait until its gets worse. She's not obvioulsy smokey when running but my mate says she smokes slightly on hard acceleration and on the overrun, just anothe view would be usefull as otherwise engine pulls well. cheers.

Sounds like valve guides to me - pretty common on old engines.

A compression check would tell you. Get the engine at TDC (so the valves are closed) and if the compression is ok it's probably worn valve guides. Heads off for that I guess. 40k is good going though.

Nik

i'd agree on valve guides . . just took apart my motor for gearbox probs at 14k and the piston bores look brand new . . .