Carb upgrade

Ok, I've been longing for more preformance from my machine for some time now, and lacking the funds for a brand new machine I thought I could upgrade my current one. Its a '98 Polaris Sportsman 500. I was doing some research and I found out the later model HO versions had a 40mm carb instead of the 34mm thats on my machine. Now is it possible to find a carb off a later ATV and put it on mine or are there other diffrences in the engine that I don't know about? It just seems to be under carbed, or restricted to some extent.

The main differences I know about between those machines are the carb and the cmshafts are different.If you just put a bigger carb on it,you could actually go to big and choke it down.If funds are limited,you can run a better flowing air filter and put a jet kit in it.You should be able to find that for around $150.00 if that much.The jet kits have a different designed needle that allows for the fuel to flow more consistant.

Well I already have a jet kit and a K&N filter on it, as well as a clutch kit. I'm pretty fluent with engines so even swaping the cams shouldn't be an issue. I just want to be sure there aren't any major differences ie. pistons, crank, valves, etc...

I think the internal parts are the same except for the cams and carb.I will do some more checking to make sure though.If you dont want to spend the money on a new carb you can get yours bored out to any size you want.Then all you do is have to rejet to get it back running right.In most cases when you increase the size of a carb,you will have to step down on your main jet.The air is moving alot slower through it and you will get a more complete burn of the fuel.A bigger carb will also cause you to loose some bottom end power cause the velocity of the air has slowed down so much.I do remember that the H.O's had more top end power than the regular 500's but the regular 500's had more bottom end power.