I'm thinking of treating the 900 to a nice Shiney gold link chain, can anyone confirm the chain spec, its on standard sprockets/gearing, 520/98 ?
Thanks

Original gearing (Final) was 15/37, which is way too tall for that engine. with that gearing @ 8500 RPM you would be going at 142MpH (Max RPM should be 9000)

I would go for a 15/39 or 15/40, you loose few miles at the top end (maybe 4-5) but you will gain some "umpf" around the mid range where the old SS900 has a couple of deeps in the torque curve.

to check if you like the shorter gearing you can "borrow" a 14T front sprocket which will work fine with the standard chainring and chain legth; 1T less at the front = aproximately +3T at the back so a 14/37 would be very similar to a 15/40

Bare in mind that the 14T would/could chew the chain on the long term (too much stress, especially on the of V2) , so it is prefereable to keep the 15T ; my suggestion is only to test the gearing before committing to a new complete setup.

with the 15/39-40 you will need to add a couple of chain links

I just did my SS750 (+2 at the back) and I like it better than before; the same goes for my 907ie, wher ebefore I had to keep changing 2-3 gears, now I keep the 3rd in and enjoy better the ride.