2007 KX250F Air Fuel Ratio Meter (AFR) Carburetor Tuning, Lean Bog off Idle

The following video takes you through the process of jetting an FCR Carburetor with the assistance of an Air Fuel Ratio Meter. The bike had a very bad bog when you took the throttle to wide open off idle which is a typical lean bog for these types of carburetors. There are many causes for these lean bogs, but the solution for this bike was a changing the leak jet from the stock 60 to a 50 and manipulating the needle clip position based on the feedback we got from the AFR Meter.
Huge thanks to Jarrod Brown at A-1 Welding and Fabrication of Sacramento, @jrad_414 on IG

AFE Air Fuel Ratio Meter
https://www.amazon.com/AEM-30-0300-Wideband-Sensor-Controller/dp/B0184TSI84/ref=sr_1_2?dchild=1&keywords=AEM+air+fuel+ratio+meter&qid=1607227119&sr=8-2

Great Video from Emerson Raceworks, AFR Meter Installed on a CRF450R with an in-depth explanation on how carbs work
https://www.youtube.com/watch?v=B3Zv1OcIfjk

Great Link on 2007 KX250F Stock, Pro Circuit and Team Green Carb Settings
https://thumpertalk.com/forums/topic/405365-pro-circuit-and-team-green-jetting-specs/

Jetsrus - Probably the best place to get anything you need for any carburetor
www.jetsrus.com

Explanation of Lambda and AFR
https://www.youtube.com/watch?v=S0m27-Fpdbs

Видео 2007 KX250F Air Fuel Ratio Meter (AFR) Carburetor Tuning, Lean Bog off Idle канала Garrett Schlegel