I have had this problem before with mine, it is from fuel starvation.
The clone tanks do not get 100% fuel pick-up. Gravity conspires against us and fuel weight pushes gas up-ward against gravity to the carb.
Check your gas cap, make sure the vent is open if it is a vented cap.
Check your fuelline for a kink or bend in the hose restricting the flow.
Check your fuel leve lin your tank, it may be too low. It will look like 1/3 tank but it`s really below the fuel pick-up. Fill your tank with gas.
Double check the engine by spraying a shot of carb cleaner in it and see if it fires up after a couple of kicks.
1972 Honda CT-70H 97cc 4 speed
2004 CT-70H -Black Clone W/124cc Motor
2005 CT 70H -Red Clone W/86cc Motor
2002 Honda XR-70 W/ 108cc Motor
2005 Honda CRF-70 W/124cc Motor