As you know, the Coleman website has a number of troubleshooting and cleaning suggestions (using denatured alcohol as solvent for lacquer buildup, for example).

But after a certain point, esp. with our local unleaded, I suspect that replacing the generator may be the only option. I have never cut one of those open; there must be a mesh matrix or similar inside there.

MSR stoves are highly field-maintainable. The generator tubes are simple, with a removable cable running through them. The MSR stove FAQ link ( http://www.cascadedesigns.com/MSR/FAQ/Stoves ) suggests using that cable to "scrub" any crud or deposits out of the fuel tube and generator. So I think it unlikely that weird fuel would totally kill one. (My old XGK is long overdue for a new seal kit; last thing I need is a flaming mess due to a gas leak. Gotta get that done.)