The engine has not been released in the USA and for now not even in Japan. The Japan release is expected in 2 months but Yamada is always late (this information is from dealers in Japan).

The factory told a friend of mine that the best thing to do is place an advance order with a hobby shop in Japan. Most hobby shops there do not need any advance payment but are taking orders. Trouble is, you need someone that speaks Japanese - either yourself or a friend, etc.

I've placed my order already

Atul