Hi, everyone I’m new to the site and need some help. My problem starts like this, I was riding my 03 grizz all day and then stopped to eat lunch and when I went out to start the bike it had a hard time to start, so I ran the bike for the rest off the day with no problems, the day after it took a long time to start and when it did start the engine started to pop or studder until the engine got warm then it purrs like kitten. I changed spark plug and gas and still the same, the problem is getting worse and need some advice, thanks.