The Truth About NOS Carburetor Kits

NOS, New Old Stock, which means a part has been sitting around for several years and may not be produced anymore. Some refer to NOS as new old original equipment parts, but NOS can also include non original aftermarket parts.

You will find some NOS and some used parts in our web store, but you will not find any NOS carburetor kits. We only sell kits that are currently, or recently being manufactured. We do sometimes get a part, or kit that has been discontinued. This isn’t the same as NOS because while the part is new, it isn’t necessarily old. Some discontinued parts may have been sitting around for a few years, maybe even 5, while NOS parts have probably been sitting around for 20, or more years.

Why don’t we sell NOS carburetor kits? NOS kits were manufactured for gasoline much different from today’s gasoline. Gaskets were more porous and made of materials not conducive to today’s gasoline. When I refer to today’s gasoline, I’m mostly referring to the ethanol that is added to gasoline. Most gaskets in our carburetor kits, are generally coated with black nitrate which helps keep gasoline from seeping through (another ethanol side effect). NOS carburetor kits usually will not have this feature. Gaskets that have been sitting around for 20 plus years will also be dried out, making them brittle and not pliable. This makes sealing our already worn carburetor surfaces even harder. Any rubber parts included in a NOS kit would surely be suspect. The rubber is probably not as pliable as it should be and in most cases not up to today’s fuel blend. Leather accelerator pumps found in some NOS kits would be OK. Just be sure to add a few drops of oil to the leather before installing. On the other side, old NOS kits that include rubber accelerator pumps should be avoided, or at least the pump not used. Older accelerator pumps were not made for today’s fuel and can easily fail. I’ll be the 1st to admit that even today’s newest methanol resistant pumps can fail if subjected to enough ethanol, but at least they give you a fighting chance.

On the plus side of the NOS carburetor kit, they sometimes include parts not available in today’s kits. An example are the old Carter master rebuild kits made in the 50’s. Carter made a carburetor kit for almost every car and there was little consolidation unlike in today’s world. Those kits often had jets, linkage and levers that are no longer available. Buy the NOS kits for these parts and throw away the gaskets, pump, needle & seat.

There is a place for old NOS carburetor kits and that is when a new kit is not available and the NOS kit may be the only solution, but why not give your classic the best you can get. Rebuild your carburetor, using high quality parts that are currently being produced and you will have less carburetor problems and leaks.





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