first step is understand the flat bits so you know you have the lobes in the correct place - then just measure and document all 8 of the clearances
then over tea, you check vs the allowable tolerance which is crazy wide - and note which can be left and which need attention
then you pop out the follower, measure or read the shim its got - and write that down - and do the maths aiming to land in the middle of the range of tolerance on each valve
or where in the range you want it - tight is worse than loose - but whilst can be engine dependent, many tighten
if it needs to be tighter you need a shim x mm bigger
if it needs to be looser you need x mm thinner...
having established what it needs, you might be able to pay mix and match - but no doubt you'll need one - and then its a trip to the dealer who will take 2 days to get it in - plus meant to use new circlips even though no hope in hell you could damage one
do not muddle up your parts or you'll be in a right mess - it's a 1hr job that takes them three days before you have your parts to complete - so if you need the bike you'll have to put it back together waiting for parts at £9 a pop !
BMW parts K25 (R 1200 GS) R 1200 GS 10 (0450,0460) Timing gear - Intake valve/exhaust valve
www.realoem.com
part----- shim ------- size in mm -- part number
| 06 | Semi-sphere | 4,60 | 11347721166 |
| 06 | Semi-sphere | 4,65 | 11347721167 |
| 06 | Semi-sphere | 4,70 | 11347721168 |
| 06 | Semi-sphere | 4,75 | 11347721170 |
| 06 | Semi-sphere | 4,80 | 11347721172 |
| 06 | Semi-sphere | 4,85 | 11347721174 |
| 06 | Semi-sphere | 4,90 | 11347721176 |
| 06 | Semi-sphere | 4,95 | 11347721178 |
| 06 | Semi-sphere | 5,00 | 11347721180 |
| 06 | Semi-sphere | 5,05 | 11347721182 |
| 06 | Semi-sphere | 5,10 | 11347721184 |
| 06 | Semi-sphere | 5,15 | 11347721186 |
| 06 | Semi-sphere | 5,20 | 11347721187 |
| 06 | Semi-sphere | 5,25 | 11347721188 |
| 06 | Semi-sphere | 5,30 | 11347721189 |
| 06 | Semi-sphere | 5,35 | 11347721190 |
| 06 | Semi-sphere | 5,40 | 11347721191 |
| 06 | Semi-sphere | 5,45 | 11347721192 |
| 06 | Semi-sphere | 5,50 | 11347721193 |
| 06 | Semi-sphere | 5,55 | 11347721194 |
| 06 | Semi-sphere | 5,60 | 11347721195 |
| 06 | Semi-sphere | 5,65 | 11347721196 |
| 06 | Semi-sphere | 5,70 | 11347721197 |