Carb Set Too Lean?

[Jim Ed]

Gene Berg mentioned somewhere not to 'lean out' the carb.

What exactly does that mean and what happens?

[Stray Catalyst]

Too lean means that the air-fuel mixture has too much air. It's often a sign of vacuum leaks, though Gene Berg wasn't talking about that specifically. An engine that's running lean, usually runs much hotter - a problem at any speed, but a quick engine-killer if you're idling, and/or have removed cooling tin.

Stray