I've been collecting lighters for over a decade. I have a lot of cool lighters, most of which don't function. I have put some thought to this and assumed the tiny orifices in the valves must get clogged. (this is how it acts, running for a split second that jamming up. Like a clogged fuel tank on a car) So i thought why not back flow fuel INTO the exit port. So I tried it by disassembling everything, draining the tanks opening the tank up then holding the valve opemn and shooting fuel DOWN the OUT valve Into the tank from the TOP. Then rebuilding the tank and refilling it. VOILA normal fuel flow rates. Re-assemble the lighter and boom its fixed. Now to apply this technique to my super valuable Colibri lighters and Gold plated Japanese lighters. Did you see my rare Gun lighter?
