RE: ys fz 63 break in
I'm always in the dark too.....small world.
To begin with I would not suggest using 15% nitro until you become very adept at tuning a YS. The nitro is an oxidizer and higher nitro content gives you a wider sweet spot for tuning, which is something you definitely want since you are new to YS and breaking in the engine and it is going to drift a bit in tune anyway. Get yourself a good known brand of YS 20/20 mix fuel or use what a LOT of guys swear by which is the Cool Power 30% heli fuel. Get a spare YS #4 or OS type F plug or two in the event you have a plug go south on you. Trust me when I tell you using any other plug will ruin your day....I learned that the hard way.
Prop, an APC 13x6 would suit you well for break in and general flying. Then just follow the directions. If you have any other questions post them here. If someone does not get your question answered just PM me and I'll make time to get you answered. but there are a bunch of good guys who answer questions here and I am VERY happy to have them here to help.