So I've been very pleased with the way my DL 50 has been running. Broke it in on the Lawnboy (two gallons), then went to Amsoil 50:1. Broke it in on a Zinger Pro wood 20 x 8, then switched to a Mejzlik 20 x 8 somewhere down the line. Then, damaged the tips on the Mej, switched to a Xoar 20 x 8. Taking RPM readings I was a little disappointed that I was turning only about 6600rpm when many others are bragging of 7000 - 72000 on similar prop. Okay, then I learn you gotta run that Amsoil at at least 80:1. So, I switched to 80:1. Engine ran great, maybe a little cooler, but didn't seem to pick up much RPM. Then switched to a new plug (CM - 6 or whatever), no improvement (but the original plug was carboned up pretty bad - probably the rich fuel/oil ratio). Then a friend loaned me another Mejzlik 20 x 8 and I picked up about 400rpm! Next flight I lean the low needle a bit and the engine's running even stronger, but still a little rich, so I lean the top end a tad the next flight. Look out!!! This thing is running stronger than ever! Maybe the combination of all those factors, along with more time on the engine (10 - 15 gallons now?) added up to the RPM increase. The engine runs so strong now that I'm starting to think a little more about what I'm doing so as to not overstress the airframe. Doesn't matter though because the moment my engine started really comin' on I destroy the plane when I momentarily loose concentration and clip a tree with one of the wings (hey, I was doing an outside knife edge circle!). Of course, buddy's prop destroyed too.

Oh well, engine seems fine (spark plug cap split apart and won't stay together so I need a new ignition - on the way from ValleyView) and already have another Extra in progress.

Can't wait to get that engine and plane back into the air. It was running really strong!

Moral of the story; 80:1, Mejzlik prop.