yep, if you're using the choke (on the carb) and you don't give it enough gas after a few seconds to pop it, then the engine won't run long at all. if it's cold, you will need to use the choke to start up your ped. let it sit a second, then give it gas (that releases the choke) and you're in business. you may want to let the engine warm up a bit before riding around.
but you mentioned a second gear ... so i'm curious ... please let us know what kind of ped you have and what you had serviced.