I used to use a white gas stove for backpacking. IIRC, fuel, once opened, gets "dirty", and doesnt burn as efficiently. It had a tendency to clog up my stove quite a bit. Something about the way it reacts in air, with the metal inside the container. I recall thinking that my stove sucked, then I came upon an article about how that happens. AS it was quite a while ago, I naturally dont remember the article. You may be able to find it by googling it.