RE: Spark plug gap
Here is a question, the answer which I have been unable to find,and I'll bet you are the guy to answer it.
I have a 26cc european built engine equipped with a tuned pipe. After a series of ignition and carburetor problems, it now has RC EXL ignition firing an RDJ6J plug.
With the plug gap at the recommended .025, it will usually start for the first flight of the day, but after that it will fire but not start unless the plug gap is set to around .018.
It doesn't seem to make any difference if the ignition voltage is 4v, 5v.
I'm thinking it could be the plug is oil fouling (since the plane is way over powered and most of a flight is at 1/4 throttle), or the ignition unit is just plain weak.
Oil is Stihl 40:1.
What do you think? Have you ever experienced oil fouling in a 2 cycle?
Jerry