Hey Flap,
During the initial break-in, I belive the Mfg. makes a point to not exceed 4,000 rpm on the first initial runs, for only a special duration of time. I belive the first couple of runs, saito wants you to use the glow warmer on the plug during those runs untill it will operate without it. These things, as well as the tach, may not be necessary, but I have found that following these instructions have given me a very powerful and reliable engine-if not that, then piece of mind. You probably will not go above half throttle at first anyhow, so you won't hit those rpms.

W8ye is right, you will seldom see people use these instruments out at the field, for my case, it is because I have spent the time doing those things at home, and have gotten to know my engines and how they operate well enough so I won't have to waist that time at the field when I could be flying.

I'm glad you asked what it means to "float the valves." When I told you to be careful, in an earlier thread you put out, not to "float them valves," I was afraid you wouldn't know what I meant. But, as you have stated, these sights are great to get a lot of perspective, from people with different understandings and experiences.