My MP Jet .061 PB.
I just finished breaking it in today and have a plane I'm going to fix up for it. It's a loud strong running engine. Super easy to crank and about as easy to needle as any engine I've ever run... except for the needle being less than a finger-width from the prop. I think I'm going to like this one. I hope i can find a source for parts. Anyone know where to get bits and pieces for this Czechoslovakian thing?