I've been using a coleman 442 . . . . it IS a bit larger than some, but doesn't require a separate fuel source, and, when it runs low on fule, I've got 6 gallons over on the bike . . . .
Been buring lead-free low test for years . . . . . .never a problem (though I DO have a rebuild kit stashed in the bottom of the saddlebag) . .. .
Searching for the immaculate contraption