Originally Posted by RWD_cossie_wil

Hi mate, have a look on the diff, there should be an ident tag on the rear cover that tells you the ratio. If it does not have one, take the rear cover off, and count the teeth on the crownwheel, and on the pinion. You can then easily work out the ratio by dividing the crownwheel teeth by the pinion teeth

I've had a look for the ZX12 gear ratios, and have come up with this:

6 speed constant mesh
Wet multi-plate hydraulic clutch
Drive chain ???
Gear ratios :
************ 1 - 2.429
************ 2 - 1.824
************ 3 - 1.440
************ 4 - 1.250
************ 5 - 1.130
************ 6 - 1.033

What size wheels/tyres are you running? What does the engine rev to?