Gy6 might need crankshaft?

[CaptainMagic]

So I bought a used ssr rowdy 150cc gy6 type B (I think) and it ran like a dream for the longest. After it fell over a couple times (not while moving) it now will start and as soon as it starts it dies, I was thinking it would need a new crankshaft as the idle was sounding like a big rig engine only much quieter. But if it catches after turning over THEN dies could it be something else? Please tell me so I do not sell my black beauty for parts!