How can I troubleshoot the reason my engine is running lean?

Answer by  eldergeek (473)

Begin by confirming the problem via the use of an exhaust gas analyzer. Check the fuel for contaminants. Next, check the fuel pump, lines and filter. Ascertain that the automatic choke is normally during engine warm-up. Consult a Chiltons, or other manual and tune the carburetor. If the problem persists, you may have to rebuild or replace the carburetor.

Answer by  Gingercakes (920)

I think you should try to adjust the carborator. The carborator is the "breathing" mechanism of all engines and regulate the gas/air mixture.