RE: Saito FG-17 tuning question
You should run the engine in by setting the high speed needle (probably half to one turn out from optimal so it starts to stumble at mid-revs) so the engine cannot exceed about 4,000/5,000 rpm for about the first 30 minutes (5-10 minutes on, then off for 5-10 minutes and so on). Try to vary the throttle settings a little.
After this initial run in, you can start to lean it to optimal. The engine takes about 4 hours to run in before you can optimal tuning (eg don't worry about getting it perfect until you have run time). Just tune it on the plane so it is realiable and not likely to dead stick. In my view, you don't to run the engine in on the ground for hours. After the 30 minute initial ground tune you can start flying the engine, but keep off the full throttle (except for take-off and emergency). After a further hour run time, running continously at WOT should be OK. As w8ye says, the engine should be propped to run in the recommend range. Make sure you use the recommended Saito fuel/oil mix (20:1 with good synthetic oil) for at least the first 10 hours.