I was loosing snow last week and the machine backfired and quit. I went to restart and battery was dead so I boasted it with my truck and got it back to house and put charger on it. Then it would fire but not start (almost a flood thing) removed carb and cleaned. Changed plug and checked spark with tester at 2000 v. It was good. I did have a leak in carb float bowl so I changed carb changed all fuel lines and put fresh gas in. It’s still almost impossible to start but once running it does run fine. Now when I got it going and took it for a ride it back fires (exhaust) like a gun shot when I turned it off every time. I haven’t checked compression yet as I need adapter. Any thoughts before I take it to mechanic would be greatly appreciated as I’m tapped after Christmas 😞. Also the old plug was black but I can’t get it to go now with new plug in to check it. Thanks for any help!