I have a 06 636. I've noticed that some times I can hear the valves chattering. The bike has Kawasaki 10W40 in it. Should I be running a heavier oil (I live in Florida, so it's never really that cold). The dealer checked the valve lash at 600 miles, and now it has 1950 or so. I'm not sure if it's because the bike is so quite at idle, or what? All my other bikes are much louder than the 636. The bike runs great, no staggering, or anything else.

 

Valve noise is usually not a problem.

It's better that you have some clearance between your cam & valves causing some noise instead of having zero clearance ruining your cam, lifters, and valves. I would stick with 10W40. Maybe go with synthetic once you hit 3000m

 

Thanks Mark.