k1200RS crank troubles

Hi all,
I recently picked up a k1200rs with a siezed bigend bearing. It has now been ground and I am positive that I can get shell for it.

The problem I am having is that I cannot find any info from BMW about how to best harden the effing thing. All it says in the manual is that it has to be heat treated...

Anybody have any ideas?

Cheers

pre 2000 K12 is well known for bottom end failure.

cure was to fit a 'cracked' rod.

rod is made in one piece, frozen, then snapped halfway across big end.

the rough edges mate exactly stopping the movement that causes the problem.

probably no help to you, but someone warned me before I bought a cheap bike with this problem so I like to pass it on

turnipbmw said:

pre 2000 K12 is well known for bottom end failure.

Click to expand...

Thats why they fitted a bigger oil pump.

You could seek out a specialist firm that can do nitriding of the crank?

IIRC this is where the crank is heat soaked in an atmosphere of ammonia which chemically alters the structure of the surface to locally surface harden the journals by absorbing nitrogen molecules through heat over time. Due to the low enough process temperatures it wont soften the metallic structure or harm the crank through cracking or change of dimensions.

I haven't used anyone for this process myself as our large marine engine cranks were as hard as nails so I guess a Google search may uncover someone capable of doing this, or else speak to the engine crank grinders and see if they have any trade contacts.