Has anybody here actually replaced the shims on 1200RS?

[KDeline]

The procedure looks daulting, (removing the crankshafts, come on BMW) and I would like to know if you bought the fancy tools required to perform this.

[Paul Mihalka]

The procedure looks daulting, (removing the crankshafts, come on BMW) and I would like to know if you bought the fancy tools required to perform this.

Just in case, you may have to remove the camshafts, not the crankshaft. That's bad enough anyways...

[beamergirl]

I just attended Max's K tech day, my understanding (and I may be wrong) is that you don't always have to remove the camshafts. The shims coming out didn't seem to be a problem, but it looked hard to put one back in. The tool (that I saw) was nothing more than a hook with graduated thickness from point end back towards handle.

 

After seeing what they go through - someone else will be doing this job.

[ShovelStrokeEd]

You do have to remove the cams on a K12RS. The cam follower is the shim, item 8 in the attached photo. There is a procedure for removing the cams so that you don't break the camshaft due to uneven pressure and that is what the fork tool is for.

[beamergirl]

I did miss about 20 mins of the session, so please help me out here. Should have mentioned they were not working on a K12RS, think it was this engine (K100?):

 

It didn't seem like anything other than the cover was removed. The wheel was turned to move from valve to valve, the "lobe" on the shaft would put pressure on the "lifter" (is that right?) - you would use the hook tool around the camshaft to release pressure between the lobe and lifter where a shim was located. You would measure the gap before and decide whether or not you needed to replace shim already there.

 

On the K12RS, I've heard the terms shims and buckets - how does that relate to a picture if you have one to post.

 

I do wish they were working on my engine, there is a big difference in the pic you show and what I was looking at - I misunderstood that it was the same engine

[KDeline]

Your way is for the older K's.

[Dennis Andress]

K100s up to the early 90s had a two valve head. There was a shim located between the cam and the follower. A hook tool was used to open the valve by pressing against the follower at which point the shim could be changed.

[beamergirl]

Thank you - that follows along with what was being done (from what I saw peeking between people in front of me).

 

So, on the K12RS, it's a 4 valve head? But what do the shims and buckets look like? (If that's being asked correctly).

[Dennis Andress]

I'm not sure, haven't been there yet. The 4-valve K100s had a small shim inside the follower , against the valve stem. I understand that the K12 uses followers of different thicknesses instead of a shim, so the cam follower is what is changed. It all has to do with reducing mass and keeping tolerances as tight as possible.

[Tool]

I've done my valves on my 2000 K1200RS... and lived to tell the tale!

 

"But what do the shims and buckets look like? (If that's being asked correctly)."

 

 

Correctly enough, De. The "bucket" is the round cylinder-shaped cover at the end of the valve stem & spring in your drawing.

 

 

In the case of the K1200, the shim IS the bucket, or the bucket IS the shim, same diff. In other words, the buckets come in differing thicknesses, where the bucket rides on the end of the valve stem. To adjust the valve-to-camshaft clearance, you DO have to remove the CAMshafts, but it isn't too tough.

 

 

First order of business is to measure - and DOCUMENT - clearances, then compare to tolerances. If the specs call for it, the bucket has to be replaced with another one of different clearance. Cam(s) come OFF, remove the bucket, look inside to determine the spacing value, then use a different bucket to modify that value.

 

 

Put it all back together. That's it in a nutshell!

[KDeline]

Just in case, you may have to remove the camshafts, not the crankshaft. That's bad enough anyways...

 

Well no wonder it seemed so hard........

[beamergirl]

Thank you, thank you so much Tool - not having an anwswer was really bugging me. It'd be great to get a used engine just to have and take apart, just to see how it comes apart and then "maybe" put back together.

 

Any engine donors out there

[ELP_JC]

Beamergirl, now that you're an expert <he he>, the technical name of the ones you mentioned is 'shims OVER bucket', and they don't require cam removal.

Our Ks use, as said previously, 'shim UNDER bucket', which in our case is BOTH in one piece (also called the 'cam follower').

In most modern Japanese bikes (also with 'shim under bucket' valve actuation), you re-use the bucket, and just replace the shim, which is removed from inside the bucket with a magnet. And they're cheaper to buy, obviously.

This is the end of the lesson. Cheers.

JC

[Tool]

Thank you, thank you so much Tool - not having an anwswer was really bugging me. It'd be great to get a used engine just to have and take apart, just to see how it comes apart and then "maybe" put back together.

 

Any engine donors out there

 

 

 

 

You are most welcome, De... if you've had enough SNOW for a while, get out to San Diego; we may end up doing an impromptu K-bike Tech Daze, since I've volunteered to help another K-rider do his valves, and I'm just about ready to do my 36k service!!

 

But be it known I am not considering "donating" my engine!