Try Valve Lash Increase for R1200?

[edvoneuw]

Has anyone tried increasing the valve lash (i.e., milding the cam timing) for an '08 R1200GS? I do this for my '97R850R per Rob Lentini's article in the (un)official Oilhead Maintenance Manual, and it really improves my idle and throttle response especially in the low and mid-range. I'm reluctant to try it on my new bike given it's higher compression.
Any advice would be welcome.

[marchyman]

The idle on your 850R is controlled by the idle air screws that you can set. The idle on the hexheads is controlled by the engine management system using stepper motors. If the idle isn't right it means your valves (side-to-side) aren't right. The best thing you can do (in my opinion based upon not much knowledge :laugh) is get the valves set correctly.

This is actually stated in the RepRom. Check idle. If the mismatch is > 25 mbar check for air leaks and valve adjustment mismatch. There's not much else you can do (that I'm aware of).

When you get the valves just right the idle balance looks like this:

http://www.snafu.org/pics/r1200gs/2009/0902-service/p-20090906-1532-5724.jpg

Can't comment about throttle response.

[New2rt]

This information when posted by Mr. Deilenberger should be of great interest, to me anyway.

"I'll be posting a bit more in a few days on some things I've discovered about how the idle stepper air-valves work, sort of interesting (to a geek/gearhead) stuff you can find out using the GS-911 (mine was klacking yesterday when I got home.. it's not anymore..) Meanwhile - I suspect the sound will go away - the engine has some capability of self-tuning at idle (part of what I discovered... it just takes a while.) "

Idle adaptives?

[edvoneuw]

Thanks for the advice. Turns out the exhaust valves were way out of adjustment. I've adjusted the valves per BMW specs, and it is definitely idling much better - not as good as my 850 (as steady as a heartbeat) - but definitely better than the rough shaking I had before I adjusted the valves. Maybe it'll self-tune like New2rt suggests...
Cheers, Ed

[New2rt]

Thanks for the advice. Turns out the exhaust valves were way out of adjustment. I've adjusted the valves per BMW specs, and it is definitely idling much better - not as good as my 850 (as steady as a heartbeat) - but definitely better than the rough shaking I had before I adjusted the valves. Maybe it'll self-tune like New2rt suggests...
Cheers, Ed

My post was a quote from Mr. Deilenberger. I don't want to take credit for his research but glad your idle is better.