i run a NGK BR8ES in my 89.works fine.thats a wierd plug to run.never heard of anybody running that.

 

I had this problem too my chain also popped and caught one of my stator wires gave it weak spark and it was har to start and also i would run NGK plugs out of your bike it depends on how you ride it to if you putt around on it i would run the b8's outta of it if you like to scream around like a nut bag like me run the b7's cause if you run the b8's your almost guaranteed to loose some horsepower unless you have a coolhead on it but thats just from my experience.And if that doesnt work get a clymer manual there is a section in it that shows you a bunch of pictures of bad plugs and the descriptions of the plugs and whats causing it that is also a big help to. Give you the best of luck i know how it feels my bike breaks all the time.