I had the same issue on my Huztl 660 kit. I just filed down the outside corners where the counterbalance lobes contacted the skirt.I will be ordering a new cylinder, may even get the big bore kit for it, may get a new wire clip and put it back together to make sure I have buffered anything else up. Where the piston runs the crank, should I just lightly file a little bit away from the skirt?
I always triple check the pin retainers to make sure they are in the groove.