hello, my name is Antonio, i´m from spain, jejeje, i know exactly what you are talking about, i´ve blown my piston twice, its scary go to 160km/h and sudenly have the back wheel blocked. Well, what i recomend you is the same thing as the other guy, use a good oil, castrol TTS its the second best choice, and motul 800 the first one, but its true that its expensive. Even using the best oil i bloed up my piston a warm day with no win riding to 160 km/h, how to solve this?, very easy, do the oil mixture to 2% directly in the gas tank, and what to do with the other oil fo the automatic mixture? very easy, some people recomend take off the bomb, but... i dont like have pieces in one place and in an other, so... i recomend you put a longer tube from the bomob and back to the oil deposit instead of to the carburator. This will solve your problem, just one inconvenient, at low revolutions your muffler will expulse a little bit more of smoke than usually. What i´ve just told you is what profesional people do in the races. Here with have the aprilia cup of 125 cc, i pretty cood race for begginers amd people how wants new nice stikers for ones bike :-P