[R1150GS head]
In the BMW training, it is suggested that the rocker arm end float be set closer to the minimum spec. The spec is very wide (.05mm/.002" to .40mm/.016") and usually leaves the factory at the wider end of the spectrum.
Since the head is torqued at the 600 mile service, it is recommended that the end float be adjusted at that time to reduce noise. From my experience as a service manager, I can tell you that few flat rate technicians bother with it. You can easily measure your rocker end float while your doing your valve adjustment.
[R2000GS head]
To adjust end float on the rocker, you loosen the (3) T-45 Torx bolts and the 15mm head nut of the lower rocker "bracket", then tap upward on the bracket until you have the desired rocker end float of no less than .05mm. You then tighten the T-45 Torx bolts to I think it is 15 Nm (I confess I don't torque these, I just snug them up), and then torque the head nut to 20 Nm then 180 degrees. Afterwards, re-measure the end float, it tends to tighten up after you torque the fasteners.
I tend to leave it a little loose then measure after I torque everything tight. I also like to run the valve adjusting bolts all the way out away from the valve so I have maximum valve clearance before I adjust rocker end float. This way you can rotate the rocker back and forth after setting end float to be certain you have not introduced any binding in the rocker actuation.
Finish up the job by adjusting your valve clearances. Adjusting the rocker arm end play affects the valve clearances — besides, you loosened the valve adjustment screws during this procedure, remember?
There is a very well-considered and lengthy (22-page) writeup on this procedure for the older R11xxGS series in the ADVrider.com Hall of Wisdom. It's called the OREPAD — you might want to check it out.
Copyright © 2006, by Ted Porter & H. Marc Lewis. All rights reserved.