I took the Dragonfly apart the other day to see what the fuel line was like inside that braid.
Today I picked up some replacement Gates fuel line. This particular example is a rubber line with internal nylon braid, rated for 50psi with fuel. I looked for the specs on the pressure the MSR hand pump can generate but found none; I’d guess 2-3psi.
The issue here isn’t pressure, but rather temperature. The stove’s heat goes up in the air until you put a pot on it; at that point some heat is reflected back onto the brass fuel stem and simmer adjustment, and the fuel line connected to the fuel stem (see pic below). I had some aluminum sheeting that came with the stove as a windbreak and figured that would work as a heat shield.
[caption id=”” align=”alignnone” width=”2560”] test run on the new fuel line[/caption]
[caption id=”” align=”alignnone” width=”2560”] heat shielding in place[/caption]
Immediately cranked up and ran like a beast again. Sounds like a Saturn V leaving the launchpad. :-) It also means I am back to burning cheaper unleaded ($2/gal right now) than Coleman ($12, or $9 for the walmart brand today).
this line is longer (2’) by design; the OEM fuel line was annoying short (1’)
this line is more supple; the OEM was annoyingly stiff
I boiled water for green tea, shut it down and checked the fuel line temp. It was body temperature under the heat shield.
I am not in love with the clip-style clamps (all the shop had) so will replace them with more robust clamps next time I’m near a hardware store. But they held with zero leakage
Calling this $8 mod not just a success, but an improvement. I packed the little Exponent stove back into the Folger’s container it hides in.