Hmmmm.....to get the EXACT size, you'd probably end up buying the Suzuki tool which, if you're keeping the bike, is not a bad thing, really......plus it probably fits a whole bunch of other Suzukis and (probably) Kawasakis too. Get your dealer to take a look in the service manual for your bike if you don't have the factory manual. It'll be in there and it'll even have the Suzi part number shown. It may be that part #09940-14911
is the correct socket. That's what all the big bore older Suzis use for that nut through about the '94 model year....and I wouldn't be surprised if the mid size bikes used the same socket too.