engine trouble, help

[HondaRider]

hi, my 1985 z50r keeps cuttin out on me, sometimes it wont start and then backfires when if finaly does start, smokes black at first....the spark plug is all oily after only like 2 mins of run time, does it need pistn rings???

[Hillz]

i would say you need a new piston kit yes, plus Black smoke = fuel so i would look at reseting your floats in the carby plus a good clean

[HondaRider]

i cleaned the carby...floats are working fine....but wen i took carby apart 2 clean it looked rusty....just looked like water had been in it its all clean now but still cuts out and smokes
o...and were do u recomend getting piston kit?