jhjacobs
Well-Known Member
I have a bunch of Zeniths completely disassembled on the kitchen table and interestingly I am finding subtle differences between them. I am curious about a couple of thing and wondering if anyone here has any insights:
1. One three of the carbs I found metering rods in the primary venturi feeds (in addition to the jets). Two of the metering rods have a small flanged input at the bottom and one is large and not flanged. Surprisingly, the carbs I have collected are in pairs and the metering rods were on one unit in from a pair and not the other. This makes absolutely no sense to me. I am going to install the smaller metering rods in both final my assemblies knowing that I can take them out. Additionally, two of the carbs have the hole where are metering rod would go blocked off with a plug on the secondaries and the rest don't.
2. One of the carb pairs I have came from a 2500S. On this pair there was a rectangular assembly on the side with a 20 ohm resistor wrapped in a brass heat spreader. This assembly is not gas tight and appears to be connected with an air feed directed into the secondary venturi. This resistor will get pretty warm with time but I can't figure out what purpose it serves. The best I can figure is that it is supposed to warm a slow air feed that mixes with the fuel stream on the seondary venturi or perhaps it is an anti-siphon mechanism? They're mounted on the outer top of the carbs and I don't plan to use them but I am curious.
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1. One three of the carbs I found metering rods in the primary venturi feeds (in addition to the jets). Two of the metering rods have a small flanged input at the bottom and one is large and not flanged. Surprisingly, the carbs I have collected are in pairs and the metering rods were on one unit in from a pair and not the other. This makes absolutely no sense to me. I am going to install the smaller metering rods in both final my assemblies knowing that I can take them out. Additionally, two of the carbs have the hole where are metering rod would go blocked off with a plug on the secondaries and the rest don't.
2. One of the carb pairs I have came from a 2500S. On this pair there was a rectangular assembly on the side with a 20 ohm resistor wrapped in a brass heat spreader. This assembly is not gas tight and appears to be connected with an air feed directed into the secondary venturi. This resistor will get pretty warm with time but I can't figure out what purpose it serves. The best I can figure is that it is supposed to warm a slow air feed that mixes with the fuel stream on the seondary venturi or perhaps it is an anti-siphon mechanism? They're mounted on the outer top of the carbs and I don't plan to use them but I am curious.