I have recently just bought a new pocket bike for very cheap, it came with no warranty. It is a 50cc 2 stroke pull start with no gears or clutch.
It worked perfectly when i first got it (a few days ago) but now it runs fine still but when i sit on it and attempt to accelerate it stalls/ dies, sometime it will be able to drive a few meters but it starts to backfire and the bogs down. It is able to be revved to high rpm when the rear wheel is lifted of the ground but not with any sort of load.
I have played with the idle screw on the carb but have had no luck. The carb is very small and has only 1 screw to adjust things. The idle is also quite rough.
Thanks in advanced for any answers.
Edit: here is a video of it stalling when i sit on it and accelerate https://youtu.be/s6u6LHSi00g