ORIGINAL: Shogun
Correct Raj, I got curious and just to see what would happen backed the high neede out on my 100 4 turns rich. Guess what? No change in the running characteristics of the engine. If you do back off the needle it basically is running as rich as the regulator will allow it too, esentially the needle can only be used to lean the high end beyond that "max rich" setting.
It's sorta weird when you first get one of these, it's something you have to kind or "wrap your brain around". I thought something was wrong at first but once I stopped trying to overthink the situation it made sense.
This just doesn't really make sense to me. I've been using the cline for a while and like I said the needle response is deadened somewhat. But I can gaurentee you that if I turn the needle 4 turns out my engine will run sloppy rich and at a lower RPM. The reason being is because the cline will give the engine what the engine requests. If the needle valve is turned out 4 turns and the throttle is open the engine is requesting a lot of fuel. Too much fuel to run properly. The cline responds by allowing the amount of fuel through that the engine requests. The result is an engine that is burning too much fuel and because of that the engine will be running at a lower RPM. If the needle is turned in and and set up lean the engine is not requesting as much fuel. The cline responds by letting a smaller amount of fuel to the engine. This will effect overall RPM. So you can see that by adjusting the needle you are effectively making the engine request more fuel and when the engine requests fuel the cline will deliver.
The bottom line is that the cline stops more fuel from coming into the engine that what the engine is calling for. A perfect example of this is the syphoning effect. The engine might be calling for an average amount of fuel while at the same time en elevated tank is wanting to push more fuel into the carb than what the engine really wants. Therefore the cline says "The carb is telling me to give it X amount of fuel and thats all I'm giving it." If you turn the needle out the carb will be requesting more fuel and the cline will allow more fuel through. This will lead to changes in rpm.
Thats my take on it. I'm not an elequant writer so I'm sorry if my response is hard to understand.