One problem with Rochester carburetors is that the fuel-filter nut requires a 1" wrench to remove. A regular 1" crescent-wrench is so large it can apply too much torque just with it's own weight. Combine this with 30+ years of unknown mechanics plying their trade before you, and it's all too easy to strip the threads of the carburetor casting. Figuring I wasn't the first person to run across this problem, I went to the local auto-parts store and asked for a solution. The oldest guy behind the counter (ie - someone who was around when carbs were still in vogue) had just the item: A replacement fuel filter self-tapping nut. Pretty slick, I thought. As you can see in the photo below, it's longer than a stock nut and has cutting notches in the threads. In theory, it's supposed to cut new threads in the undamaged portion of the carb casting. In practice, it thoroughly ruins whatever threads you have left, necessitating a new carburetor airhorn (Argh!). In calling around to the various carb places on the internet, the first question after I asked if they had an airhorn was, "Why - did you strip the threads?". When I next mention the self-tapping nut, a few chuckled some more. One even said such items should be illegal. Thanks to this board, another club-member had a good carb for a great price (Thanks, John of M&M Automotive!). I'll be posting pics of the rebuild later this weekend. In short: If you strip the filter threads, DO NOT buy this self-tapping nut as a fix! Your only solutions are to get a replacement carb; have yours heli-coil'ed by a rebuilder (about $150-$200); or you can replace the nut with an o-ring fitting and use an external filter.
There is another way to repair that problem. I have used it when in a bind it has two O rings and tightens on itself when you tighten the 1" nut. But another bowl assembly is always the best way to go. Mike
Yup, I was looking for a link to post of such an "O-ring Fitting" (as I called it). It's a smooth metal cylinder with two O-rings around it. It slides into the carb body in place of the fuel-filter and then is tightened, the O-rings expanding to fit the bore. The fuel line then attaches as before. Of course, there's now no fuel filter in the system - you have to cut the line elsewhere to install an external filter. When originality doesn't matter, this is certainly the cheapest and most effective method.
