Holy cow.  Breaking in this Enya on the bench.  I have run about 4 tanks of 2 oz so far.  Just fired it up with one flip.  It runs like a raped ape.  
Not seeing any 4 cycling at all so far.  I start with recommended 3 turns open.  Runs great, but FAST.  LOL.
I am running 10% nitro and 24% oil.  
Did I mention it starts on one flip.  I am getting a consistent run at this point.  No sagging at all.  Just FAST.  Did I mention 2 cycle FAST.
It may be a fast stunter.
I am planning to use for a Cardinal.
This thing could probably haul a .60 size plane.
By the way, it starts best by smacking the prop backwards.

I have 2 I bought, used R/C versions, cheap. I think the R/C guys never broke them in. Swapped the carb for a 7mm venture and an Enya NVA. After a couple short runs, I ran a full 10 oz tank of GMA 10/29 then another tank of GMA 10/22. I flew one on a Brodak P-40 on an APC 11.4 X 4 and 62' lines. Lots of line tension and lap times weren't too bad. If I hadn't destroyed it in crash #4 this year, I'd probably switch to an 11 X 4 prop and 63' lines. Great engines.

If you use a low pitch prop and high rpm, be aware and prepared to deal with fuel foaming. If fuel foaming happens you won´t be able to adjust rpm with the needle. If you need help how to deal with fuel foaming do ask so we can help.

You may want to check with Randy Smith for a lighter CNC tube muffler for your engine.

I flew with this engine, but w/o BB, in a Pathfinder with an APC 12x4  and I agree with you, it is powerful enough to fly anything up to 60oz.

Martin