I have an eton 50CC with a big bore 70CC kit. New battery. Electric start does not work and dont know why. it cranks with a weak spark. If I kick start it, it fires up. Why wont the electric start work?

 

Other than weak battery I'd check the ground wire/battery connections, theres also a groundwire to the engine/trans case. If it seems to turn over fast but not engage there is a one way starter clutch that is behind the front clutch/variator and this can get dirty and not engage. Hope this helps.