i'd check your spark plug caps, i had something similar happen to me cause i was running it one day and then like an hr after running it started to run very shitty like spitting & sputtering and then the right side just died and the left side was kinda half running ... and it turned out to be the spark plug caps after trying plugs, checkin reeds, etc... but i duno i'd change them cause there cheep (3$ each).