I use my Juwels and Arara 37 and whatnot every few months. I would love a Meva but they dont turn up often here. I think they have the equivalent of "Nur für Benzin" on them too. Once I was stupid enough to fuel up a kerosene burning Primus with Coleman fuel. Ran great as I remember....nothing blew up, and I snuffed it when I realized what I had done.
Sadly, in the US now, most pump gas is 10 to 15% ethanol -- which wreaks havoc on rubber fuel lines and fuel pump diaphragms. In fact last week, my friend and I were diagnosing the No Start gripe on my '71 GMC Jimmy -- which had just died in my driveway after a parts run for my '68 C/10 pickup. We went all thru the HEI distributor, then decided to test the fuel pump. Rather than disconnect the fuel line at the carburetor, we took a Sigg bottle with Coleman gas and splashed a little into the primaries. It started right up. Even though Coleman Fuel is about 65 octane and I run 91 octane in the GMC's 350 V8. So now the Jimmy needs a new fuel pump, I still have to fettle my Arara 37.
