Rich / Lean... What does it mean?
Posted September 11, 2006 - 04:41 AM
Posted September 11, 2006 - 04:57 AM
What confusesess people with 2 strokes is the ratio of engine oil added to the fuel. With the same carb settings a pinger running 28:1 will be leaner (a/f ratio) then running 40:1.....................the added oil displaces the amount of gas passing through the carb while the amount of air remains the same.
Posted September 11, 2006 - 05:01 AM
An over rich carburetor adjustment is when the proportion of fuel in the combustible air/fuel mixture is so high that the fuel does not burn well
A lean carburetor adjustment is when the proportion of fuel in the combustible air/fuel mixture is so low that there is not enough fuel to burn
It is also used to discribe the mixture of oil/fuel in a 2 stroke. Lean meaning more fuel and less oil ,rich meaning more oil and less fuel.
Posted September 11, 2006 - 05:12 AM
Posted September 11, 2006 - 05:21 AM
Dry and white means you are running lean. Black and wet too rich. Plugs that are a tan to brownish, cocoa, is the color you are looking for. Re jetting your carb is the usual way to correcting richness or leanness. There are a few other things that can effect fuel flow through the carb, how clean is the air filter, obstruction to intake and or exhaust, position of the jet needle and air screw or fuel screw setting.
This pertains to both, two strokes and four strokes. With two strokes you have one more variable to deal with, oil ratio.