Sled has 2000K miles on it. Runs great for a bit but then we make it work a in this amazing Utah snow I get a bog. I have to feather the throttle and ease off, bring it back to life and off she goes......For a minute or two. Then wash, rinse repeat. On the flat, she does ok but I am used to better. Fuel system is clean, new fuel filter, plugs, carbs rebuilt etc. When I pulled the plugs on the mountain I did get a VERY STRONG hit of bad gas. I was stupid and could have been better about summer MX. I run premium non-ethanol fuel. I have a ride Friday with my grandson and my amazing son-in-law. (Yes, those do indeed exist) Today is clutch day. I have already done some Exterior cleaning of the primary clutch. The belt looks ok and is FAIRLY new. This sled just has NOT been ridden much in the past several years due to the lack of snow. I am NOT as adept at messing with clutches but if there is someone out there who can point me in a direction of doing some adjustments that will get this "Bog" nonsense to calm down I will do it. Do belts go bad just sitting? I am fine with just tossing the belt aside and putting on a new one and making sure the adjustments are ok for the belt. THAT I can do. I ride typically above 7000' all of the time. OR, is that bad gas just going to cause more fits until a run a tank or two through it? Is there a fuel additive you recommend beside Stabil that works miricles? I have spent HOURS working through my sins of NOT doing better summerization. I am close. This Summit had moments of granduer this last ride but when faced with having to WORK a bit, she just was not all there. Best RPM on the groomed flat was about 6800. I just want a good day for my boys. Any advice from this well informed group would be appreciated. I know there are no shortcuts but maybe I am missing something simple.