After 30 odd years of biking, I've done summit I thought I'd never do.
My boy rides a 1992 SR125 and last week I ordered a chain and sprocket set. I took my time ordering and pointed out it was a 92 SE model. Anyway I removed the chain, rivetted link, front and rear sprocket. Front sprocket no probs, Rear sprocket, the bolt holes do not line up. I measured between the centres and there was a difference of 12mm. The new sprocket was 80mm and the old was 92mm.
As I said Needs Must and my boy needed the bike for work this afternoon and college tomorrow, so I had to put the old sprocket, which by the way was well past its sell by date, back on the wheel. Not ideal and prolonged use will fuck up the new chain so hopefully the dealer will send me out a new sprocket asap.