Keil Kraft Radian

Good morning Guys,

I've had this one since the beginning of early 2019. This kit was built by a gentleman in England. His thread is on RCG:
https://www.rcgroups.com/forums/showthread.php?3071837-Building-a-Keil-Kraft-Radian-with-a-Cox-TeeDee-O51

Mr. Matthew and I tossed some email traffic back and forth as he built this plane. He shared some of his build methods. This thing is beautifully constructed! He shared that his friend called the plane capable (this is coming from a Combat Pilot's mouth). I thought I had showcased it here before, but cannot find a reference thread. Anyway, imagine my surprise when Mr. Matthew offered to have ME fly HIS plane. I can't imagine how much it costs to ship a completed kit "across the pond." I know how much it cost to ship a Lil Satan up the east coast of good old USA (hint: not very cheap!). I was also very concerned about the plane making it in one piece. Mr. Matthew asked for two things...Enjoy it, and video-record flights. Is that all? Now you know why my stooge must work flawlessly. Just to show this kit's build quality, it was used as the promo picture for the kit maker's catalogue...it has a "pedigree in print."
https://www.vintagemodelcompany.com/kk-replicas/22-kk-radian

Early flights were difficult as the engine was difficult to needle appropriately. Some good bench runs caused me to think I just wasn't doing my part right at the field. Each outing would be an exercise in frustration, with the plane languishing in the air until the tank ran out...then me hanging on for dear life through each short but furious lean-run. I tried different fuel blends from 15%N to 25%N, yet the engine failed to produce usable and stable power. I certainly couldn't try any stunt with an engine prone to flame-out...definitely NOT with THIS plane!

After much wringing of hands, continuing benchtests, and continued troubleshooting of the fuel system, I reached out to FredV4 for his advise. I came away with two ideas based on Fred's question: How do I KNOW I'm NOT over-compressed? Well, the short answer is "I don't know." So this weekend, I stuffed another two glowhead gaskets in and went flying. I'm so glad to report the engine runs quite well on previously mixed fuels, is easy to start (finally), and runs with a consistency that I hope will lead to more exciting flying...because I can now trust the engine. I may add one more head gasket. I will try higher nitro for more power. I will make longer lines so I can use more sky.

Feel free to rummage around the other videos (I think three). Each flight I ran the needle in 1/8 turn until the last flight. The tank-emptying lean run wasn't a huge diffence from the early part of the flight. I suspect I was on the edge of just a bit too lean. Here is one: