First, I want to pass on a big Thank You to Jody at Valley View. I have never talked with him, just e-mails. He has gone above and beyond the norm in helping me with my DLE 20 (and another engine I have).
I recently ran my engine a little warm (ok, HOT) because it did not have enough air flow, the engine died and the plane made a hard landing/crash. I'll make another post when I get a chance that has pictures of what happened. The plane is back together, but more importantly, with Jody's help, I installed a new piston, ring, and spark plug. I also cleaned out the carbon build up in the head area. So I needed to run a tank thru it on the ground at low idle. While doing this, the engine jumped up in rpm's all by itself. I have read several people stating the rpm won't drop to idle right away, and that is what mine was doing from day one. I could almost tune it so that it did not have this problem, but it still did it. I just learned to land the plane knowing that this will happen. Anyway, while running the engine at low rpm's, I had my son make a video of the rpm change. You will see that when making small throttle-up adjustments with the trim tab, the throttle will jump up over 1000 rpm's. When adjusting the throttle trim back down, the rpm will jump back down. The engine in the video is not tuned for flight. The needles are set at 1 1/2 out on the high, and 1 turn out on the low.
Here is the link to the video: http://www.youtube.com/watch?v=pdZl4...el_video_title
I'm not complaining here, I love this little engine. Pulls my GP Extra 300 around beautifully. I just wanted people to see the rpm thing that is caused by the weird ignition timing curve. It's also hard to tell, but the rpm's drop real fast after the last throttle down adjustment is made. It does it all by itself.
Oh, and it looks like I am dangerously close to the prop with the transmitter, but it's just camera angle.