I have a Saito 72. As bhole74 said, make sure it has at least an 18% oil, especially during break in.

You will need a tach to set the engine properly. The engine should be producing "smoke", especially at full throttle. If it is not producing smoke, you either have insufficient oil or are running it too lean.

After 2 or 3 tanks through the engine it will be reliable enough to fly, but it will need about a gallon through it to completely break it in. About every 2 gallons of fuel you will probably need to adjust the valves. You will know when - the power will drop off a little. I run mine inverted with no problems. I suggest hand starting rather than using an electric starter. I also suggest using a drop of locktite on the set screw for the needle valve extension, they tend to vibrate loose.