Fellers,
It's been a while since I have read this thread but it has been opened up again. I have bought the YS10FZ and love the engine! Besides some foaming and lean running at first (detonations), the engine has been trouble free. Well, almost anyway. The engine pulled away and seperated the firewall from the plane after only about 4-5 tanks through of flying (yes the YS's do HAVE POWER). I rebuilt the plane better, and stronger and have not had other probs since.

The YS engine just keeps on running like a champ. I'm still flying with the original plug I bought with the new engine! I will by another in due time......

Dennis