Left cyl in fully open > adjust right in, same 'opposite-system' for the rest.
To find the exact point, remove plugs, put it in 4th, get the rear wheel off the ground and rotate.
Good instructions are in the owners manual, see
page 22.
As for clearances, there may be several opinions, make your choice after searching the forum, and reading the relevant service sheets
here. I've seen in .008 to .010, out .010 to .016 for plunger\iron head. Too much clearance is much safer than too small. Some members here may share their optimal and well tested clearance settings.
As to
when, now and then, or after each weekly engine rebuild
Good luck.
