User Review: Optimus Hiker+
The stove wants to be CLEAN because at the very end there is a TINY little jet that can clog easily. Initial problems will result if you fail to CLEAN the tank prior to use. It's easy to clean. Put in about 6 ounces of fuel, shake well, dump out fuel, repeat 3 times. When new the tank is NOT clean.
I replace the little filter often. It's impossible to find a seller for the little filter without buying the entire service kit (which only contains 2 filters). So, I use a razor to cut down a .177 airgun "cleaning pellet" which is made of dense felt-like material. It takes a little practice, and a tweezers to insert the new filter. Pipe cleaners, wet with fuel clean the fuel feed tube perfectly.
My fuel of choice is "Klean Heat", a kerosene substitute - available at Home Depot. It burns very well and is truly odorless. I get a nice blue (proper combustion) flame, with only the slightest trace of yellow at the edges of the flame.
Use Neatsfoot oil on the leather pump "cup". A tiny tube will last forever and keeps the leather in good shape. If you find you are pumping A LOT - your problem is either a clogged filter (common) or the regulating screw/grooves need cleaning. The key to having a happy stove is keeping the internal parts immaculate.
I would have given the stove a zero review until I took the time to take it apart (using just my Leatherman tool) - and gave it a complete cleaning. WOW - now it just needs a bit of pumping and the flame is really HOT LARGE (if I set it so) and a nice shade of BLUE.