I have lit my dual fuel lantern for the first time. It worked just fine but i later loosened the fuel cap and now the lantern stays pressured up but doesn't burn as bright. I have now emptied all

SOURCE: trips breaker starting under load

The problem that you describe is caused by pressure in the airline due to faulty in-tank check valve and/ or the unloader at the pressure switch. When the compressor cycles off the pressure switch releases the air that remains in the air line thru a small valve. There is a 1/4 " tube extending from the check valve to the switch. Listen for the release of air as soon as the compressor stops. There is a small metal tab that pushes on the unloader valve that may need to be adjusted. The motor does not have enough power to start pumping if there is air/backpressure in the air line. If these parts are working correctly then check the value of the start capacitor and use meter to measure. The cap should test within 95 % of stated value. Replace parts as needed. Enjoy

SOURCE: Coleman 424-700G Burner/Pressure Issue

I had a similar problem today, After taking the ump assembly to pieces i disovered that the pump"stem" needed turning slighty anti clckwise to allo tepresure to build up inthe tank. I felt very stupid buta big learning curve for me.

SOURCE: Coleman 424 Dual Fuel -- High, yellow flame

Are you pumping the tank up all the way? I have the same problem if I have too little pressure in the tank. The instructions say pump 35 times. Try pumping 50 or 60 times- that seems to help.

Also, you can't light this one like an old 425. My old stove you could turn the gas on and then take a match neat the burner. For this stove, hold the match near the burner with the gas off and quickly turn it on.

These are two things that seemed to help me with the same problem.

SOURCE: will not hold pressure when fuel tank pressurized

lube or replace pump seal try Vaseline on seal pull d clip and twist out pump rod end of pump rod apply lube or vaseline to round tab and to seal under retaining clip re assembly if works good if continues replace-walmart coleman= k mart=gander=any outdoor/sports goods carry

SOURCE: i have a coleman lantern model 220k but i cant seem to build any pressure. the pump valve acts as if its at max pressure capacity. while pumping with my thumb over the hole its to stiff to pump.

did you turn the knob counterclockwise to unlock the pump