Thanks for all the suggestions but I'm afraid this thread has grown entirely too large and has gone on too long. If you read back (and I agree, it's too much to read through) you'll see that all these latest suggestions have been tried. And I've tried FAR too many things to list them all here.
However --patternwannabee-- what I had intended to say was that the tank is 3" behind the carb. which puts it immediatley behind and adjacent to the firewall. Also, poly(urethane of ethylene)foam is the industry name for what most people refer to as foam rubber (which is actually made of rubber). Polyfoam comes in lots of different densities. I'm using 3 different densities -soft , med. & firm -- similar to the "Isolastic Suspension" systems pioneered by the British in the '60's to stop vibrations at varying frequencies and some of the pads used are actually the "rubberized heavy foam padding sold for RC to cushion rx's" (real foam rubber). Densities are aprox. 1 pound per cubic foot to 4 pcf.
I think that for now, I'll just fly as much as I can and depend on the onboard glow starter to keep it running. On the last flight of the day last Sunday, it didn't cut out at all but it was late and I had to go. Maybe it has already fixed itself.

Ken