Last week I was happily cruising down route 3 in MA in my '55 GMC 3/4 ton w 270 (not stock engine for that ear, but its what is there.) at 55 mph. Suddenly, there are a couple spaced out huge backfires, the engine quits, and i coast to the side. She won"t start, spins fast and spectacularly back fires thru the carb. We get towed home, and i am figuring that 1985 Nitrophyl float has had it. Or maybe the main fuel jet fell out again into the fuel bowl.
Took carb apart, a Holley 1904/1960 single barrel, everything looked normal except the carbon in the horn. Got an NOS brass float and needle/seat assembly from ebay, put it all together, and still same gig. no run, backfire.
i am wondering what could fail suddenly like that...valve timing engine timing..will check that next. Thoughts?
Last edited by Dave Douglas 56; 11/09/2013 7:13 AM. Reason: wrong date on float
