The ignition timing and fuel mixture would be a very good place to start. First make absolutely sure the electronic ignition is set to fire where it's supposed to, which means make sure you know where 28 degrees is with respect to TDC, and that includes checking for TDC through the spark plug hole.
have a 2000cc VW with the same configuration in a motor glider, top set of plugs on a slick magneto and the bottom set (automotive plugs) fires off of the Bosch electronic ignition and it idles smooth as silk with both set to 28 degrees. I just want to thank all of you that replied to my plea for some help and/or suggestions about the backfiring issue, both to all who replied on the net and also to my personal E-mail. Now I can't wait until Thursday when I can get back to the airport and start using your suggestions. This really gives me a direction to go and at least one of these will pan out Im' sure, if not all together. I'm sure that you all realize what a great thing it is that we have here to support the construction and successful flying of the KR1, KR2, and KR2S's. Thanks again to all, Neal Hornung lt1corve...@earthlink.net EarthLink Revolves Around You.
