Hello all. I am fairly new to working on snowmobiles, and I am currently working on a 1999 Polaris Indy Trail Touring (488cc). The sled had been running on one cylinder since I started it a few weeks ago. I wasn't sure about cleaning the carbs myself (never having done it before), so I took them off and brought them to a Polaris dealer to be cleaned. They told me my main jet was the culprit. When I got it back I put everything back exactly as I had taken it off. I also changed the fuel filter and had drained the old fuel, as well as adding new plugs. Well, it fired right up on the third pull (choked) and was idling perfectly! It hadn't sounded that good in a while... The sled had been in my garage and I drove it outside without any issue where I let it idle for probably 20 minutes. I then went and shut it off with the thought that I would go for a test ride later on. However, when I returned about an hour or so later, the sled would NOT start. I tried everything I could think of including spraying starting fluid in the plug holes, some gas in the plug holes, new plugs, checking to make sure my gas lines were not pinched anywhere, kill switch, etc. I checked for spark and that was fine. I pulled the fuel lines off at the pump and carbs and there was no issue with fuel getting to the fuel pump or from the pump to the carbs. There was no gas leaking out anywhere that I could see. It seems like there isn't any gas getting to the plugs... every time I looked in the plug holes it seemed overly dry (sometimes the plugs were mildly moist, but I think it was from the starting fluid/gas I was putting in). I'm not really sure what else to try since both starting fluid and gas directly in the plug holes didn't seem to make a difference. It's so weird since it idled beautifully for 20 minutes! Perhaps I wasn't putting enough gas in the plug holes?? Any help or suggestions would be appreciated!