ORIGINAL: gaRCfield
It is best to tune a 4 stroke with a tachometer;
Two words -
B. S.
It is never a good idea to tune an engine with a tach.
4-strokes are no more difficult than a 2-stroke, but there are two rules:
1) you MUST use a 4-stroke glow plug.
2) they run better with 10 - 15% nitro.
Aside from those two things, they are just like a 2-stroke. Get one, you'll love it!
PS, as far as adjusting the valves goes, I have been using 4-strokes almost exclusively for about 20 years and have needed to adjust valves once