MY last build,china girl 66 cc, never ran good from the start,you know how they are a crap shoot.well anyway i tried everything i know to remedy the issue,bogging something awfull from the day i bought it,checked for air leaks,none found,swaped carbs no change,swaped coil, no change.so today i took off the head and cylinder,all looked good.had some blow bon piston below rings so i investigated further,found lower ring had no alinghment pin allowing ring to rotate on the piston.swaped cylinder that i ported and polished,replaced piston with one i skirted,new rings,put it back together and it runs better than it ever did.it is on a genesis onyx with custon tank and exhaust all black bike,i
call her my black widow