ByPopularDemand

Can someone explain the two and thier differences to me please

monkeydude3

running lean = sometimes more power,slightly increased MPG, drastically more combustion chamber/cylinder head heat and your engine will not last under this condition, you can see it by very white spark plug tips usually


running rich = a little less power, less MPG, fouled spark plugs, not as rough on your engine as running lean. This will show up as dark spark plug tips, usually coated with carbon

you want your mixture as close to stoich as possible

monkeydude3

and you know you have a good mixture when your spark plug tips look like light grey, with nothing really on the tips, LIKE MINE

rbstang

lean - more air then fuel
rich - more fuel then air