szr 660

i have an xt660 supertenere but it is running an szr engine,last week finished work startd the bike it ran for about 2 seconds and then stopped and wouldn't start again,got a new plug for it no change,changed the coil over no changed,getting a good spark took air box out sprayed easy start into the carb bike fired, have a remote fuel tank feeding the carb directly there is fuel in the bowl.Took carbs off and cleaned all jets with carb cleaner so i think it may be a fuel prob, but i am open to suggestions carbs are not my forte so i have drawna blank the bike has never let me down so far,any suggestions