I just bought an 06 Honda foreman 500es and the guy rode it last night and said it ran out of fuel. I added fuel and replaced the spark plug. It’s getting gas to carb and is getting a nice strong blue spark. All it has done is backfire out of exaust twice and the carb a couple of times. And only does that when I shoot ether in carb or poured a little bit of gas in the sparkplug hole. Any ideas?