nxrsr20 wrote:It's not sparking or there is too much fuel. Check your float height, your jets are in properly and have correct jetting for your settings. Try swapping plugs or a new plug.

+1 Most probably the float height or seal, on the front cylinder carby. Need to watch this as it most probably means that you are leaking fuel into the front cylinders crank case. This can cause hydro locking if you leave the tap on for an extended period of time...