There are high altitude clutch weights. Those will increase the engagement RPM, thus returning most of your lost low end.

DRIVE CLUTCH - A06LB27AA/LD27AA/AB/AC/AD Polaris HAWKEYE 2X4/4X4 (A06LB27AA) 2006 OEM Parts - Cheap Cycle Parts

Order the 12 gram rollers, you'll lose some top end speed though! It's always a trade-off.

Then if you want, you can buy a dynojet kit for about 60 bucks, it really wakes up your machine, while you're in there, drilling the slide will help with throttle response.

 

Hard to believe going from 22" to 23" would make a difference in performance. Did you also go wider or something?

A 300 should turn 23" tires not problem, My 350 4x4 Grizzly has 25" tires stock and turns them easy and the ATV does not even have a low range. Its motor is only 48cc larger but its frame/chassis is bigger also.

 

I agree the easiest way to increase the power is to buy a 500!. Trust me I am looking. Not sure how much time/money want to invest in this machine as a 300 will always be a 300. Thanks for all the advice and the links to better clutch weights for this model. Will keep you posted if I buy anything.

 

The 300 Sportsman would be a better machine if it had a "normal" Polaris clutching system that you could do something with, but it mainly was designed as an entry level machine and still used the Hawkeye,Phoenix and Sawtooth type clutching. With a 500 you can do quite a bit. Good luck. OPT

 

you have to figure- by the time you spend the money for the parts & time & labor to install it all- for maybe a very slight gain in power, if any at all- you'd just be better off with focusing on finding a 500.