Help with 100cc 4 stroke

Thanks to everyone for the suggestions and to the guy who gave me the valve lash specs. They were spot-on! Did the valve adjustment and found the exhaust valve was loose and now problem solved! It runs awesome and starts easy now, no cutting out or backfire. Still have the shaking issue, but I’m going to buy the clutch someone mentioned in this thread and I’m sure it will fix it. Just came back from an 11mile night ride with my son on his 2-stroke bike he built and it was a blast! Thanks again!
Ran great tonight. Still some shaking but I think it is the clutch. I’m upgrading that this week. Hit 45mph also! Is a blast!