420 Rancher starting problem

I fired my 2007 Honda Rancher 420es up today and it ran fine ,started it back up backed it off the truck then it shut off,hard to start and then when you give it gas it dies.Then it would not start just try and backfire,nothing no start just turning over and back fireing occasionally.I checked my spark plug and its fine but the spark when you trun it over is strong and fast then weakens and slows,,seems like the efi system is loading the cylinder with gas then when I do get a good spark it back fires.any advice for today with the dealership closed,crank position sensor,???

THe same thing happened to me while riding at 2 in the morning but my FI light was blinkjng