Good morning I had bought a 60 cc motorized bike from cl about 4months ago it ran great for roughly 3 months until it showed a decrease in spark and wouldn't stay running unless I kept pedalling so I changed the magneto and it seemed to work just fine after for a few days now is back to sounding like not enough power or spark, while I pedal it sounds as it wants to run but not getting enough power, so I changed spark plug and still no fire what could I do now to get this thing going it makes no sense how it worked with new mag then just stopped??? Thany you god bless!