I think it may be time to freshin up the ole ninja. . I had trouble keeping up with an 05 mustang gt today, i raced him from a 20 roll and we went to 140mph, but i only had him by about 2 bike lenghts. It has 152,000 on it now, i put in new main and rod bearings at 80,000, but have never done the top end. Should i do just the top end now, or rebuild the whole engine? The bike runs perfect and always had, doesnt smoke orburn a drop of oil. Give me some opinions..