|Figure 1 The Bing 64 CV (constant velocity) Carburetor|
The carburetors are easy to maintain with very few moving parts, rely on good design, and relatively simple operation to garner their great reputation. Most of the problems that we see on the CV carburetors are created by the operators, inadvertently and primarily from a simple lack of knowledge on basic operation, maintenance, and troubleshooting. In our Light Sport maintenance classes, there’s one universal area that will cause a student to sit up straight and pay attention: Troubleshooting! We tell the story constantly about how easy it is to troubleshoot an engine problem. (For this article we will say engine/carburetor problem). It’s as simple as this. Step 1: Inspect the engine/carburetor to find out what has changed from the stock configuration. Step 2: Change it back to stock configuration. Step 3: Run the engine to verify that everything works perfectly. Now, we may be joking a little bit about this whole process, but it really is true. Most of the time when a customer brings airplane with an engine/carburetor to us, that isn’t working properly. We simply hunt to find out what has or hasn’t been done to the aircraft that now makes it different than when it was a new engine. Keep in mind that these engines are all manufactured on the exact same assembly line, under extremely controlled conditions. If we can simply put the engine/carburetor back to the same configuration which it was when it rolled off the assembly line, it is, once again, going to operate like a “new engine”. Of course, the problem with this whole concept is having the requisite knowledge to be able to easily identify what is no longer in the “stock configuration.” In order to make good troubleshooting decisions, we need to start with a good understanding of the CV carburetor’s theory.