49cc 2 stroke scooter need help running

[hanivw]

hello guys i have a 49cc 2 stroke scooter.........i rebuild and replace every thing in this scooter, and this thing dont runs right .....well got new car , reeds , jugs, heads , pistion kit, gasket , fuel vaccum pump, batery , and every time i put it together get it running it will kill the pistion i out 3 to 4 different pistion and it killed them also with the head , it seems like the piston is comming too far and hit the head , but its the right size piston , the last 2 time i got it started it starts idel and start revting fast and arattle noise and idel very fast and stop , well i try to open the head and etc.. the jugs and heads was realy hot... and i got it open , wel another pistion is damage just from the top....please let me know whats up and whats happening and how to fix it please thanks hani i would like some feed back thanks again

[harry]

sounds like its the spark plug
piston is hitting it breaking the piston and ramming the plug upwards
since its in the head it cracks the head as the piston drives the
spark plug up . is the electrode smashed on the plug?
you might try 2 base gaskets to "make" the cylinder taller

oilyhans

[hanivw]

,.,.dance.hello thanks for the reply . no the plug is good it seems like the edge of the piston is getting hitall the way around but not the center...............it used to not to do that ........thats wired.................snf the head is not crack thanks hani let me know

[FreakyBeanie]

try pre-mixing your fuel. you might have an oil problem. is the vacuum line for the oil pump plugged on the carb? all I could see is that it overheats and explodes. but i'm not sure i've never heard or seen that happened...especially 3 times in a row. unless something is assembled wrong???maybe running 2 lean also ??? you should post pictures of the dammage...