Spark Plug Chart

By physically checking our spark plug color we can determine whether the air and fuel mixture is too lean or too rich.


Spark plug color chart

Record Log:
On Mikuni VM22 Stock Carb

• 7 June 2013 Plug physical condition Hot or Lean based on chart second row from bottom, between second and third from right.
  Mainjet #105 Pilotjet #22.5