Krazy,,,,,I have put about 20 flights on this engine so far. I was almost going to sell my EF Yak because it did not fly all that well, but after replacing my other engine and pipe with the 58, I dropped about 2+lbs and now it is finally a joy to fly.
The problem was with idle and a click or two above. If I tuned it one way it would lean on extended idling, if I went the other way it would be a tad too rich in the air. Now all is good.