There are a couple of things. If u want more top end, then go with a bigger rear sprocket. If u want more acceration but less top end, go with a little sprocket. There are pipes, carbs, and better port and boring jobs that can be done. The sky and your wallet is the limit
you could get a big bore kit an exhaust re jet the carb get it ported get smaller tires and rims for the back new bearings changge the gearing. it all depends on how deep your wallet goes [img]images/graemlins/burnout.gif[/img]
I don't agree with trading it on an e-ton 70. The polaris is made by e-ton if I am not mistaken. You can get a cylinder kit at HotSeat Performance and make your existing atv into a 70. The best bang for your buck is getting a larger airfilter, rejetting and a pipe. You can find them at hotseat, Hpd-Inc or several other suppliers on the internet and spend less than $500 and have a 50 that would give a stock 90 a run for its money.