Thanks about your answer, and now I am a bit confused..
I dont wanna spend a lot of money for exhaust or something so will probably try clean(melt) the pipe, but still want to upgrade on the 70cc piston set.
Maybe it is a mistake but now i made another list: the 70cc airsal set, polini reeds, polini intake manifold, clutch plates polini, better airfilter.. and the carburator maybe later.
What you think about this?