Hi,

When adjusting the valves on my XR650R I do the rights thing and rotate the flywheel counter clockwise etc to ensure the auto decomp isn't engaging, but I was also told I MUST do the following:

"You need to be sure that the manual decompression lever is not actually trying to open the exhaust valve while you are setting the valve clearances. The easy way to ensure that this is not happening is to remove the cable either at the rocker cover or at the decomp lever on the bars. You would be surprised at the number of people I have come across with XRs who set the valves incorrectly by not thinking about the manual decomp lever."

I have never done this - is this guy right?

Scoobie

When you hear the loud click while you're kicking it, you know the auto decompression is not activated.As far as the lever goes I've never messed with it for a valve adjustment. I use the sight hole in the case to do my valves but it takes an extra pair of eyes.

Scoobie said:

The only thing I can make of this is that a lot of guys have the lever adjusment too tight. This would certainly give a tight exhaust valve clearance. I think that as long as you have adequate free-play at the lever you should be fine. I adjusted my valves a few weeks ago, it seemed really straightforward with one exception: don't let the flywheel turn backwards at all as the piston comes up on TDC. This would certainly cause the auto-decompression to engage and tighten up on the exhast valve.