I bought a clean low mileage 04 last April, and during the hunt read many warnings about this 2nd gear "problem" with Hayabusa's. Been reading around on here, but not really coming up with a clear answer to the question in my head, which is:
Is this problem related to people doing powershifting, clutchless shifting, whatever you want to call it, without a quickshifter installed. A quickshifter cuts the throttle momentarily and at exactly the right time to allow the gearbox to unload, which allows the shift to occur without banging the engagement dogs together. Doing it by simply trying to time the right hand throttle with your left foot can lead to gearbox damage if not done correctly. I know because I've been into a few bikes I've bought used and seen the damage, rounded off engagement dogs on the gears and bent shift forks.
My bike had the original owner, 60 year old guy, only ~6000 miles, and he babied it, no powershifting, in fact it still had the original tires, so I know it wasn't run hard. It is just fine, no problems at all with the gearbox.
Is this problem related to people doing powershifting, clutchless shifting, whatever you want to call it, without a quickshifter installed. A quickshifter cuts the throttle momentarily and at exactly the right time to allow the gearbox to unload, which allows the shift to occur without banging the engagement dogs together. Doing it by simply trying to time the right hand throttle with your left foot can lead to gearbox damage if not done correctly. I know because I've been into a few bikes I've bought used and seen the damage, rounded off engagement dogs on the gears and bent shift forks.
My bike had the original owner, 60 year old guy, only ~6000 miles, and he babied it, no powershifting, in fact it still had the original tires, so I know it wasn't run hard. It is just fine, no problems at all with the gearbox.