My wife's 240 is running very rich about every 3or 4 months I have to replace the spark plugs. I've already tried replaceing the air flow meter, no help It runs better with out it pluged in. Not that its that much of a big deal due to the fact that even after a year or more of driving we still have less then 0 tied up into this, even being a daily driver. What I'm thinking is if I could lean it out some it might get better gas milage , I have no clue what the mpg is, but I know that its not what it should be. any thoughts?