Went over to a buddys house to test this new master cylinder I put on, (BTW guy on ebay selling them for 75 bucks, very nice aftermarket brake and clutch master cylinders!) anyway I am still looking for a wrench to get out my 2 and 3 plugs on my 82 CB650SC. Well I go cruising home and never noticed I had not hooked up the #4 spark plug wire. I'll have to say it ran fairly well on just 3 cylinders actually!! LOL. Only difference was a little less power down low but at 45 to 55 couldnt really tell!!!