If you ride low altitude the stock clutching in this catalog is what you should use. I would set up the primary stock with a fresh spring and make sure the weights you have installed are the correct ones (the code is stamped on the weight). The secondary is more questionable...on the 500 I've found the straight helix to be just terrible, but it might work better with the 440. If you are looking to upgrade and pay some extra money you could check out www.startinglineproducts.com (or others) and email their tech support for the proper upgrade parts to match your sled. A multi-angle helix and matching secondary spring would probably be the best upgrade, if you need to upgrade. On my vmax the straight helix is great and I wouldn't change it, but on the SKS we had to go to a 38-34 because the straight 34 made erratic shifting (high rpms at low speeds, declining at higher speeds). I know there are companies that will sell you upgrades, but the question is do you need them? I would ride it first. A lot of problems can be due to a worn belt or a new belt on a sled that is tuned for an old belt (belt deflection setting). I have never acquired a sled that had the primary set up properly for my altitude...that is probably not as much of a problem in the midwest, but you never know. People screw around with their clutching, can't figure out what to do, sell the sled, then you are stuck with crazy weird performance until you set it back to stock.
At any rate, start with learning the basics of clutching and ride it and then it will be an easier question to answer. You are going to learn a lot just by checking what's already in there and putting in fresh springs. After that you can decide if you need to upgrade. The idea is to match the engine power band against the secondary shift pattern (ideally also matched against the type of riding you do like trail vs powder). If your model does not have a tach it will be a little harder. I highly recommend getting one off ebay for cheap and install it yourself. I did that with my first Polaris and it's simple to do and surprisingly easy to find one that will work for your model. If you have a clutching chart under the hood, which you should, it should also tell you your target peak RPM. That's what you're looking to hit, and if you go over it the engine will produce less power and wear out your crankshaft bearings, so don't think that if 8000 RPM is good 8500 RPM will be better...only if the engine is designed that way and it isn't.
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