The temperature at which the oil will start burning is called the flash point.

GTX 10w40 213 degrees
Mobil 1 15w50 230 degrees
Valvoline 10w40 216 degrees

I use Mobil 1 15w50. Flash point is 230 degrees. Where did you get that information, as I get really close to 230 degrees.

Those "flash point" temps are where the vapor "may" ignite. Not sure where those temps came from but they seem low; most flash points are in the 400 range. EDIT: I think those are Celsius temps.

Completely different than the temp at which oil breaks down.

Just an FYI, I spoke to Dustin Whipple & Teague, they say heat is the enemy of blower motors & 160~180* is the recommendation, water 110~120*, no more. In fact Teague says condensation gets worse @ higher temps. (though I would agree boiling should clear it, until you cool it down idling into the marina, where it would condensate again).
Whipple believes my issue is block pressure, Teague says run it

This site has the lower numbers...

http://www.calsci.com/motorcycleinfo/Oils1.html

This site has flash points in the 400's

http://micapeak.com/info/oiled.html

It would appear that the flash points in the 400-500 degree range is correct.