OldBob I have heard same problem from another SK owner and heard also after sales service of Kangke was great from him.But like Artisan, I recommend you to play a little with carb and after checking, excersize it by manually to prevent it from future sticks.Im so happy with my SK 50 s and I think you will too.
Also I wonder who will be the first to try a Tower muffler on a SK to compare the potancial power of SK s.