Rich or Lean

[brad_300ex]

I am new to atvs What does it mean to run rich or lean. I apperciate the help. Thanks

[crashinmatt]

to run rich, it means that u r pumpin too much gas to the air that is coming in. this usually fouls spark plugs and u get a lot of carbon build-up. not too sure about the long term effects. running lean means that ur not gettin enough fuel. with this the engine runs hotter. long term effect u could melt a hole in the piston and total screw-up ur motor. it is better to run a little rich than to run lean.

[VegasEx'r]

I think that all you will do when you run rich is waste gas, not have as much power & you can foul your sparkplug. With that in mind (at least IMO), it is better (when tuning a carb) to start rich & work your way down to the right jetting. Also, when you are running rich, the engine will bog, or act like it is out of fuel at WOT, and the sparkplug will br black. When you are lean, you should hear a "lean pop" (it sounds like a backfire) when you let off the throttle really fast. The plug will also be a whitish color. When you are just right, the plug will be a tan to brown color.