Hi everyone; ran my aristo mike the other day & after running for awhile it started loosing power! Inoticed the pressure guage was down to 35-40 psi.( I've got it set at 55-60psi.)! I removed the fuel hose from the loco & opened the tank valve, to find, not much volume of gas coming out. Pulled the gas jet out & blew backwards thru it; everything clear! Pretty good pressure coming out of the tank "fill valve" when depressed, also! Recently I had fabbed a fill valve to work on the large neck , non threaded, combo fuel, 1lb. dispensers, out of a "cheapy" camping burner I bought. I had to do some soldering & used resin core with liquid flux. There was a slight leak at a threaded portion of this adapter & when I disassembled it to seal the threads I looked inside the tube & found a bunch of "crusty material" there! Now I realized I had to pull the tank & clean it & all the lines completely. I tried to scrape the material out of the tube with a small screwdriver, with not much luck. I'm assuming it's flux residue, but, I'm not sure. I've heard about contaminated fuel canisters,but, never experienced that either. What would you guys suggest I use to clean the fuel system out with?