stupid question perhaps - oil change before/after valve check?

[the Ferret]

It depends on your mechanical aptitude. You have to remove so e parts, including the valve cover which covers the top of the motor, and a side cover, turn the crank until one set of valves are open, be able to feel the amount of drag on a feeler gauge rotate the motor until the other set of valves are open and again feel the drag on a different feeler gauge, and determine by those measurement if the valve clearance is withn tolerance or not.

If they are its pretty easy and you button everything up. IF not THEN it gets complicated.