I let a friend borrow my blaster and told him to use 2 stroke oil if he ran out, well he put weed eater pre-mix in the injector reservoir. I did not know this until we went out ridding this weekend and by the end of the day the blaster would not Idle on it’s own and the plug was fouled. After working on it for a while it dawned on me what he might have done so I called and asked and sure enough that’s what happened. So what should I do? Drain reservoir? Will the piston be ok? As fouled as the plug was I would think it got plenty of oil!

Drain the oil & check the compression.