I would contact Ken Enya and tell him, seriously, he's pretty good to deal with and that does not sound right at all, perhaps if you could ask him for a replacement piston and cylinder ?
It's surprising to me, every Enya I own has an exceptional compression seal (the exceptions being secondhand, flogged out ones), you probably bought a friday afternoon engine.
The compression on mine is sparkling to say the least, arse-ripping would be more like it. If you could imagine that. I find it to be a very impressive engine and will looking for another one day. I haven't finished bedding it in yet, although it's very close. I'm still fiddling around with my Enya 15 V's, both new and both requiring a huge amount of time to break in. It's phenomenal how much time they seem to need, damn their oily hides.