A friend gave me his Butterfly (Petromax clone) to repair for him. He picked it up in a yard sale years ago and never did learn how to operate it, so I was selected as his repairman. I found the following: Fount empty, smelled okay. Filled the fount with kerosene and pumped it up. Got fuel gushing out of the control knob fitting AND where it joins the main body. Removed the control wheel/eccentric and the fitting it screws into. Found NO packing of any kind (factory goof or precious owner?). Put good quality thread compound on the fitting and placed two O-rings (back to back) on the control shaft. Pumped it up and no more leaks. The control knob (pricker) now works smoothly also. The pump is not operating correctly......pumps a couple of healthy surges, then skips about four times. Removed the pump assembly, oiled the leather and lapped the joint where the rod joins the cup brass (in case there was an air leak on the pumping stroke. Not much difference, so it looks like a new leather cup is in the future. I finally filled the pre heater cup with alcohol, left the pricker open and lit it. Just before it burned out I started pumping and......Glory be! It lit! And without any flame up or other nonsense. This thing is bright too....that 500 cp mantle is far too bright to stare at, that's for sure. After running it for about a half hour, I noticed that it had been flickering, just a tiny bit. It's not objectionable, but it's there and I'd like to fix it if possible. Is there anything I can do? Oh, the air gap is set to its maximum (I'm at 4000' altitude here). Thanks for any suggestions!
Ah, of course! I'd read that on here, but forgotten about it. I'll dig up some fine stranded wire, like speaker wire, and wind some inside the vaporizer. THANK YOU!
You may add a spiral of stranded copper wire in the lower section of vapouriser upper part. The spiral should touch the inner surface of vapouriser tube for good heat conduction and dissipation.
Carbon building up on the pricker rod can cause problems with the light output and so can insufficient pressure or there may be a little carbon in the jet and that can be cleared by turning the pricker control knob.
You might first of all try the pricker needle. Then I would use the mixture screw, if there is one. Then check the pressure and then in the end use some metal mesh in the vaporiser. Although some flickering is of no problem.
Either brass mesh or copper wire wound into a spiral spring like Coleman does. Both should work well and lessen the pulsing.
