ORIGINAL: SJN
I think you are mis-reading the saito manaul.
It says that the clearance must be within 0.03 and 0.10mm
''
In that position, adjust with the included gauge and
hexagonal wrench so the tappet gap may be set to
almost zero when the engine is in the compression
''
With a gauge in between the valve and tappet the gap may be set to almost zero.
Not without a feeler gauge....
But you are right that 0.10 is probably too much, as it is at the maximum of the reccomended gap.
I will adjust it to 0.03mm
NGH says between 0,03 and 0,08.
When i set the clearance on gas engines, like SAITO, and this one NGH i set the clearance to almost zero without the feeler gauge. But i'm sure the valves are fully closed.
I only use the 0.03 feeler gauge from the OS 4S toolkit when i adjust glow engines.
Best regards