ya, i was previously aware of the decomposition of gas, but i always thought it formed crystals, not a varnish like substance. so should my dad and i pull the tank out and clean it out, and blow air through the fule line, followed by fresh fule?
One piece of advice based on my experience: find an old mechanic who is experienced in working with old vehicles before you just throw parts at the car. I had been having problems with my 1978 Oldmobile Cutlass and would have to prime the carburetor to start the car if it sat for a while. I replaced the fuel pump which didn’t help. I was advised by the independent garage that maintains my other vehicles that the Oldsmobile needed a carburetor and that wells in the carburetor were leaking down when the car sat. They suggested that I should replace the carburetor. Since I have the service manual, I was going to try to rebuild the carburetor. What I couldn’t figure out was why, even if the carburetor leaked down, I couldn’t start the car if I cranked it long enough without priming it. Finally, the car got to the point where, after it started, it would run about 5 minutes and stop and I would have to repeat the process. I found an older mechanic who does carburetor work so I had him come get the car to evaluate what needed to be done. A day later he called back and and the car running beautifully. A neoprene section of fuel line had deteriorated on top the gas tank. He replaced the line and the car starts and runs perfectly. Apparently, I could get the fuel pump to pump enough fuel when I primed the engine to overcome the deteriorated fuel line. Now there may be an issue with the carburetor leaking down, but I can start the car without much cranking. I’m glad I sought out an expert rather than tearing into the carburetor.