I was test driving a Gixxer yesterday that I'm looking at buying. When I would rev it up and let it whined down in 1st or 2nd it felt like the chain would skip a tooth or so. When I got back from riding it the chain had about 3 inches of slack. Also the guy who owns it said he put a smaller sprocket in the front and it still has the stock chain on it...is it possible for the chain to "jump" "skip" like that???