The last mechanical I bought for "gas" about three years ago leaked all over my hands the third day out to the field,, that made it the "last" one I bought.
About 20 years ago when I got my first gas engine the sixshooter for gas was the only hobby shop option, the tygon tubing got hard the first year making it pretty much unusable. I went to a primer bubble for an outboard engine,, then I'd let gravity do the work by letting it siphon to fill the tank,, it was slow but effortless.
many ways to skin a cat,, find which way works best for you and have fun,,, the electric pump is my way now and I'm not looking back.
good luck
p.s.
Sig still sells a pump for gas
http://sigmfg.com/cgi-bin/dpsmart.ex...uel_20Pumps_01