Hi everyone my name is jim and iam new as of today. I just traded a grizzly 660 for a max iv. I have had it a couple of days and am liking it more and more every time I use it. It's a 90,s model with a 20 hp magnum Kohler on it and I am at the point where iam looking for things to do on it to get more power from it. Last night I had it a few places were it just didn't have the power to climb certain hills. I have downloaded motor manual and am going to go through numbers to identify the machine correctly. Questions at this moment are what can I do to the clutching and with the oil sentry system on that motor will it make it cut out on a steep incline. When I tried to climb the hill in my story it sounds like iam losing one cylinder or the motor is loading up. Plugs look good and brown. My gas cap could be another issue it was broke and leaking so I put one on from a Skidoo snowmobile and iam not sure it's venting. And this tank was replaced with a plastic one which iam not sure if it's oem but looks to be. I definitely need to get more power from it even if I need to upgrade motor. Thanks can't wait for some input