Hey Troy - Just wanted to let you know that I got my engine running very reliably now. I put in a new plug and put on a 14x10 prop, which I know isn't really any less of a load than a 15x8, but it was the only other prop I had on hand. In the end I had to significantly lean the low speed mixture and slightly lean the diagphram screw. The engine now idles and transitions very well, but I'm still not able to get more than 9k RPM, so I'm going to try to prop down to a 14x8 or 14x9. The engine is in a CA Models Widebody 60 and I'm able to do knife edge loops and vertical snaps so I don't really need any more power, but will prop down to keep the engine running cooler. Thanks for the help!
Steve