My riding partner has the same issue with his ZR 600 EFI, if the throttle is held at any constant rpm for anytime it'll bogg down. He rarely sees it happen, but when I 2-uped on it with my wife or when his wife road it, the hesitation stated acting up. (yes we ride conservativly.. )
If I remember correctly therr was a service bulitin on the throttle body or linkage that was suppose to help. I'll have him check and get back to you.
Yeah faster I'm right there with you!! Tap the throttle and she comes back to life?? I know there was a recall on part of the actual throttle lever (the little round discs that the bolt goes thru to hold it to the handle bar, but I don't know if that would have any thing to do with it?? I never had mine replaced, didn't even hear about the recall untill two weeks ago.
There called throttle seats and they do wear out. those who ride on and off the throttle wear them out quicker. only cost a couple of bucks and any one can replace them.When they wear the little tang out they dont make contact with the throttle position switch telling the sled that the cable is broken or out of adjustment. The sled will do it more often if you stand up or ride double because your changing the angle you push on the throttle. Easy fix once youve been there. Efi's seem to be a lot more sensitive.
Pull the pin out of the throttle, when you pull the throttle away from the handle bars you'll see 2 almost clear round seats, one on top of the throttle block and one on the bottom. Sometimes they stick in the lever so be carefull when takeing them off. The one on top is the one your concerned with cause it has a tang that hangs down that makes connection with the throttle safety switch. It may look good but be worn enough to cause your sled to bog or back fire. That switch tells your sled when the throttle is stuck open and shuts it down. The sled will run with it messed up but it won't be right. Good luck