I'll agree to Dreddi's procedure expect for one thing- 200 rpm isn't enough rich for many engines, and isn't rich enough for any new engine. "New" would be anything that doesn't have at least 5 tanks of fuel through it. The reason being that every engine unloads a bit in flight, meaning that it turns more RPM. The difference can be just a little in cases of draggy airframes and low pitch props where most of the loading comes from the drag of the blades being swung through the air, or it can be a lot with slippery airframes and high pitched props. How much prop you are running has a big impact too. If you overprop your engine, it won't unload as much as if you prop it for max power or under prop it a little. Our engines need to be set a little bit rich on the ground to allow for this unloading, so the final test is to see how the plane flies. To give an example from my hangar, my Kaos unloads a lot with a TT .46 Pro and a 10x6 prop. It needs to be set 1000 rpm rich on the ground to get maximum speed in the air. I've experimented with it using a tach to get the setting right and have found that I'm down on power in flight if I go to 500 rpm rich on the ground, indicating that it's too lean in flight. But my Ugly stick running a ST G90 and a 13x8 prop doesn't unload much, so it flies best set 400 rpm rich on the ground. With a new engine, you should allow for the unloading, plus a little more to keep the engine slightly rich when in flight to provide that little bit of extra cooling and lubrication as everything runs in.