You are absolutely correct. In the past I have been concerned when people wanted to modify the Gas/Glow mix because as created, it has about 33% methanol, which is enough to keep the glow plug lit if you use a four stroke plug. As you say, adding more oil will effectively lower the methanol percentage and perhaps affect operation. The OP doesn't make it clear if he wants to run a glow plug, or keep the ignition. I was rather assuming that since he was buying an ignition engine, that perhaps he wanted to keep the spark ignition, and just use the Gas/Glow fuel mix to get a little more power and cooler running.

http://www.rcuniverse.com/forum/engi...-glow-how.html

AV8TOR