G1 Air Cleaner

[GMB74]

I think we are debating a fine point here, but for the sake of a good arguement, let's have at it.

You are correct that for a given engine, a larger carb (larger venturi) will supply a larger volume of fuel/air mixture than a smaller carb. This is the restriction you are referring to.

For any given carb and intake setup, there is going to be a certain amount of resistance to the air flowing through the filter and intake hose. For any given throttle position,if the engine cannot draw in air due to this resistance, it will draw fuel through the carb's jets and you will have a richer fuel/air mixture. This is how a carb's choke works and why an engine runs poorly with a dirty air filter. This is the restriction I am referring to.

My point is the original air intake system with its foam prefilter, paper air filter, and rubber hose has more resistance to air flow than the K&N's simple oil-saturated element. K&N makes a big deal about this in their literature.
This lower resistance (less restriction) is going to allow more air to flow faster into the carb, with less fuel pulled through the jets, resulting in a leaner fuel/air mixture. Look at all the posts about Yamahas running poorly if the airbox is not sealed up tight. They are running lean because the carbs are tuned to allow for the restriction of the air intake system.

In a 2-stroke engine, if you run too lean, your engine runs great. Until it siezes due to high combustion temperatures or over-revving. Many snowmobile engines were burned down in the past by their owners removing the carb covers and leaning out the jets "to go faster".

My caution to the OP is to read your sparkplug to be sure your less restrictive air filter is not causing a lean fuel/air mix that could damage his engine.