Loose crankshaft nut

[Oz Vision]

I have never had the right side crank cover off until today - long overdue.
Plenty has been said about loose balance shaft nuts, but has anyone has the crankshaft nut on the right hand side come loose?
I took the RH cover off to overhaul the water pump and found the crank nut backed out and chewing into the sidecover. The tab on the lock washer that fits into the slot in the claw washer had busted off and the nut was spinning on the end of the crankshaft thread, so that is damaged also. I can probably resurrect the side cover where the oil seal fits but the crankshaft thread may be a challenge.

No wonder the water pump wasn't functioning properly, all the gears on the crankshaft had about 5mm of play, so I guess that the impellor gear was not meshing with its drive gear! That explains why I was losing coolant. It was overheating and escaping out the overflow whlist moving. Also explains clunk in engine that has always been there.

[Rikugun]

Bummer! :o  I hope you can salvage the threads.

I'm not sure of you are the original owner or not...Is it possible the cover had been removed by a PO and reassembly was not "by the book"? Was there evidence the cover had ever been removed before? Chewed up cover screws, non factory sealant squished out along the mating surface, etc? How many miles on the bike?

[QBS]

Oz, what you describe is definately not a V idosyncracy.  Sounds owner induced.

[Oz Vision]

Believe I am the second owner, had 34,000 klm when I got it and now has 40,000(25,000 miles).
Looks like the cover had never been off, no marks on case screws and no sealer evident at all, mating surfaces perfect. 
Tab on the lock washer had definately been bent over only once.
Thread damage is worse than I first thought, hope its not a complete teardown.

[Oz Vision]

This is what greeted me!

[QBS]

Can't imagine what happened.  However, please be advised that that oil seal is critically important for getting oil pressure to ALL crankshaft related bearings.

[fret not]

How are the threads in the nut?  If they are boogered just replace it.

You can get a metric thread file of the correct pitch to clean up the crankshaft threads.  It will take some time and elbow grease, and proper use of the thread file.