R1200rt cam chain slack

While doing routine maintenance on my '07 R1200RT, with the valve cover off, plugs pulled, gear in 6th, turning over the engine by hand from the rear wheel, I noticed a "click" or metallic noise coming from the right-hand side of the engine. Closer inspection revealed noise when the intake valves were closing. When my neighbor helped turn the rear wheel to turn over the engine, we noticed that the cam chain had quite a bit of slop on top when the noise appeared, but when turning the engine until the intake valves opened, the slack dissappeared and the chain tightened up. Being somewhat overly optimistic, we put the pieces back together, started the engine, and no more noise; then took 'er for a test ride, ran it up to red-line, and all appears well. Question: Does it sound like it may be tensioner failure, or is this a common occurrence? I never experienced anything similar on my '05 R12GS (no longer held), nor have I noticed this before when adjusting the valves on this bike. Nearest dealer is over 200 miles away. Any suggestions? Maybe time for a new left-over '09 GS?
Thanks!!
Pete
'07 R12RT
'83 R100RT
'80 R65

Did you have both spark plugs out when doing it?

Just primary plugs on both sides; the secondary plugs were still in.

I don't think this is uncommon. Particularly if you reversed the direction of rotation on the engine. Without the engine running there is no oil pressure to activate the cam chain tensioners. Some folks hear a bit of chain slap on cold start-up until oil pressure builds up internally.

Thanks, Marty; that makes sense to me. Come to think of it, the oil was drained at the time we were rotating the engine to adjust the valves. I'll keep on listening until it becomes a routine or common noise or something comes undone; the RT has 48k miles on it, so between now and the next service interval should be a good test.
(Good to hear from a fellow Oregonian, even though we now live in Alabama.)

I hear it too, if I have no oil and the secondary plugs in. Have no idea what those things have to do with it But, you're not alone. I have an 08 RT with 9k on it and just did the valves for the second time 2 days ago.