Sounds like you have a problem, noisy is normal, going out of adjustment that fast is not.
If you need to adjust your valves more often than the 2500 km oil change interval something is wrong. I'm averaging 5000km between adjustments.
Check the set screw securing the rocker arm pivot pin, if the screw came loose the pivot pin can slide down enough to allow the rocker to be loose but it will still run. A guy at the Blackdog rally had this problem on a new Gobi. There were several of us looking at it yet didn't see it until we really started taking things apart.
"Take care, sir," cried Sancho. "Those over there are not giants but windmills".
Wind-Mill MK-III aircleaner conversion,
Custom foam filter element,
OE needles, 2 shims,
air screws at 5.03 "Hg,
Ural European performance exhaust (cats intact).
Spin on filter conversion,