Quote:
Originally Posted by zoulas
I thoroughly appreciate you feedback but in the interest of learning something (for me) how does it do that? It seems the manual choke is simply a lever that closes the butterfly on the top of the carb (choke) and actuates the accelerator pump to get some extra gas in the carburetor. I thought the 'richness or lean-nes' of the fuel/air mixture is controlled by the screws at the base of the carburetor.
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Greetings, zoulas!
Those screws at the base of the Carburetor only control the engine idle fuel to air mixture ratio. The actuation of the Accelerator Pump only squirts a little extra gas into the throat of the Carburetor during acceleration. Without that little bit of extra gas, you would experience a "flat spot" during acceleration, meaning that you would notice the engine temporarily "stalling out" or "hesitating" for lack of better terminology. The Accelerator Pump has nothing to do with getting extra gas into the Carburetor itself. Closing the choke forces the engine to draw extra gas into the throat of the Carburetor thereby enriching the fuel to air ratio for cold starting. Opening the choke fully too soon after starting a cold engine will result in the engine stalling, and operating the engine with the choke almost fully closed will result in excess fuel consumption, and the "washing" of the cylinders and crank case oil dilution that I previously described. Get a book on how Carburetors work, and you will have a better understanding of how they work, and have an effect on engine operation and fuel economy.