Quiet is bad on a Zuk engine, it means
burned valves if left unchecked, and the
adjustment should be more like every 15
Thousand miles to be safe, change the valve
cover gasket every time, the lash spec is
about .006 for intake and .008 for exhaust,
there is no torque spec that I know of, but
needs to have the adjuster nuts tight enough
as so they will not come loose, but not too tight
Wild