You can do it a bunch of different ways. I can tell you now though that you will have to put in a 2.0 needle and seat. The engine uses the fuel in the float bowl of the carburator before it refills causing the engine to bog down, if you do any kind of mod to the governor. This is also done for longevity of the engine. You can zip tye the governor spring. Use as many zip ties as you like. You can find out where the governor spring is located by going to www.brownleisureworld.com
Click on snowmobiles and pick the year Kitty you have, it will give you a list of parts. Another way is to loosen up the bolt that attaches the throttle control lever to the throttle return shaft. To do this procedure check out www.obups.com
. On the bottom of thier page is instructions. The next way is to go internally on the clutch side. Good luck, also you might want to make the fuel mixture a little more rich. The engine will rev a lot higher, so a little more oil won't hurt it.