My reply was based on 2 Hatori 650's that I have and used when I flew pattern in the mid 1980's with a YS 60. It looks exactly like the pipe he pictured. I have a new Hatori 900 on a helicopter and it looks completely different with bumps around it. The YS61 was the engine that came out as a replacement for the YS60 - but still in the 80's. Most used the Hatori 650 on that engine as well.

Sam