ORIGINAL: MinnFlyer
I agree with most of what has already been said, however I must add that I have only adjusted valves once - ever (and I have been using 4-strokes almost exclusively for over 20 years)
I have also never used a tach to tune one. Can you tune a 2-stroke? Then you can tune a 4-stroke.
About the only difference is that a 4-stroke does NOT like to run lean, so if you're adjusting the needle, and you can hear that it is starting to get too lean, BACK OFF (or you might spit the prop off)
And ditto on sticking with OS and Saito your first time. Although both are more user friendly, OS seems easier to tune, need much less break-in time and spit MUCH less slime on your plane
+1. I check the valves about once a year. If they need adjustment then I adjust, no big deal. I only adjust the high ends about twice a year, when the weather gets cold and when it gets hot. That's about four clicks defference from season to season. I run YS and OS. I'm not a big fan of Saito but that's just a choice thing. YS is not a good choice for a first timer but it is the best of the best. Just not a good one unless you understand them. The big difference between a two and four is the two will pull a lot more RPMs and the four will swing a bigger prop and put out more torque. They also have a better throttle responce through the mid range and you get better mileage. There really isn't any difference in how to tune one.