I posted a bit about the EME70 in the 3dhs 91" Yak 55 thread on giantscalenews.com, but I'll put it here too.
So far I'm quite pleased with the motor. I got nine flights on it last weekend, which makes 14 overall. It was a tad lean from the factory, which amounted to it being quite hard to start. Richened the low end about 1/3 turn, and she fired up. I tried leaning the low end back down a bit after the first 3-4 flights, and it just didn't want to start like that, so I kept returning to the richer setting. It was slowish in transition from low to high, which made me think it was still rich. But on the fifth flight it died in the air. Motor was quite hot, could feel heat radiating from the cowl in fact. Cowl wasn't baffled, and it's a Yak, so that wasn't ideal. I pulled the cowl and baffled it, and then I also pulled the plugs and looked at those. It was definitely still running lean, not white, but definitely not a nice brown color either. Richened both low and high needles a tiny bit. Still slowish in transition, but each flight is getting better, and now after the nine last weekend it feels more like a dle-55 and transitions pretty well and quickly. It's just needing more breakin time I think. After the gallon or so of fuel it has now it's starting much better. Initially it was taking at least 3-4 cycles of choke, flip to pop, un-choke, and flip until fire to get it to run. Now it's acting more like it should, and starting easier. I think the extra friction of the twins just makes it slower to start. But it's definitely getting better and better.
As for rpm data, I'm now turning a Falcon 24x9 at about 6700 rpm on the ground, on the first runs it was 6550 or so. Hasn't increased past the 6700 mark yet though. Been running redline at 35:1 (35:1 is manufacturer recommended), but I may go to 40:1 as it's still spitting a lot of black stuff on the plane. But it's not broken in completely either.
