Erictan, if you don't have a tachometer, you really should get one. I have not found the YS to be especially temperamental, but you'll get a lot more out of your engine if you know just where you are on the rpm scale.

As to turns on the high speed needle, I would start from way out--three turns or more--then just fire up the engine and see how she runs. A new engine running rich will pop and splutter and run kinda rough. I would just turn in the high speed needle until it's running a bit more smooth and steady, and let the first tank run at that setting. For the second tank and thereafter I would just turn the nv in one click every couple minutes, keeping an eye on the tach as well as listening to the note coming from the engine. The low speed needle is an air bleed, which means ccw goes leaner, cw goes richer. You can probably start off with the factory setting, or if you do mess with it, then start off with just maybe one turn out--better rich than lean on the low end. Run the engine with throttle wide open for the first few tanks, and be sure you're generating plenty of visible exhaust.

As to your fuel, please don't run with 18% lube--either get another jug of higher lube fuel, or get a bottle of Klotz synthetic and add 3 oz to your Wildcat jug.

Once you get the engine in the air, be sure you have a plume of exhaust when your throttle is open. If you can't see the exhaust, bring the plane in and open the nv a click or two.

Nitro at 15% will probably run OK, but you'll definitely get more power at 20%, and more still at 25-30%. Also, I've found that I don't get as much power with 20% heli blends as I do with YS blends. Not sure why that is, but the difference is noticeable.