Hi Razorback58,

I would start with the plug, I had a BME 5.8 that I had the same exact problem with, and I sent back the ignition, put in a new carb kit, purchased a new hall sensor, jumped up and down alot, re-ducted my cowl, I was just convinced as all get out that it was a cooling problem due to the fact that it happened as soon as the engine got warm. (Sounds familiar doesn't it?) keep in mind all of this took about 2 months right in the middle of summer[:'(][:@][X(]. I had looked at the plugs they looked fine, not to mention that the engine ran fine at idle. Then one of the experts at the field said, "man it sure sounds like the plugs are about to go south." I told him, "no the plugs are fine look at them, plus it runs at Idle when it is cool???" He said, "go buy some plugs."

I asked the member of the club to watch my plane and I ran down to the Napa store and bought new plugs, took about 10 minutes to get there and back. Then I installed them another 10 minutes. Started right up and ran like nothing had ever happened, I spent 2 months and butt ton of money for no damn reason, well maybe my own stupidity.

Your plug is most likey fouled in the 3500 to 5000RPM range meaning that when the conditions in you engine are right, Temp, Pressure, and everything else going on in there. The plug due to fouling can't get enough spark out to keep then engine running.



Kurt Cook
Fromeco Scale Avionics LLC
www.fromeco.org