Hello. Does somebody know viper stock chain widht? My original was 13w and after fail I get new chain and upper sprocket from CAT dealer. Get 15w chain and wider sprocket and they have little different tooth profile than oe and now i dont know can I keep original lower sprocket? And why there is 13w chain in Yamaha,(My one misconstructed?) every 4 stroke CAT seems to have chain and upper sprocket 15w and lower 13w.