Man, how embarrassing!! [

] FALSE ALARM. I just took it apart and measured it and it is a plain old 25cc engine. I thought the cylinder looked different than the 25cc engines I have, but after getting it apart I see that it is not, and it measures out at 25.4cc.
Oh well, I'm bummed....
Hey wait, I wonder if I can make my other 30cc Echo pieces fit into this crankcase? I'll have to look into that.
AV8TOR