you need to be more specific, like what is it / isn't it doing?
do you have spark?
is fuel getting into the carb?
is the choke on or off?
is the clutch adjusted right?
is your wiring correct?
is your spark plug wire snapped onto the spark plug?
is your spark plug tight?
is the plug gap set right?
what carb. does your engine have?
if it has the older style n.t. carb, it will have a small primer button on the left side.
turn your gas on and pump the primer button a few times to prime the carb.
you may have to pull the float bowl off off the carb to make sure that gas is actually getting into the carb.
there are a bunch of things that can cause the engine not to start, but you have to have the 3 basics...fuel, air, compression and spark.
start with the basics...check for spark and fuel, check your wiring and the connections. make sure that no bare wires or bare connectors are touching anything.(i personally hate those push together connectors because they will eventually fail).
make sure that the white wire isn't hooked to anything, and that the end is cut off and capped.
make sure that you have the fuel turned on and if your carb has a secondary shut off valve on it (a white T on the right side) make sure that the T is in line with the fuel line.
make sure that you have your carb. installed right (i have seen them installed sideways and upside down). make sure that you have the carb slide in the carb the right way (it can go in 2 different ways but only one way is correct).
fyi, you don't actually have to peddle the bike to start the engine.
if you have a hill or slight incline, you can just roll the bike down it, and when you gain some speed, let the clutch out. (providing that the engine runs to begin with).
