Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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General Operation

The MCU monitors the oxygen sensor voltage and, based upon the mode of operation, generates a control signal for the carburetor stepper motor. When the system is in the closed loop mode, the air/fuel mixture will vary according to the oxygen content in the exhaust gas, and the engine operating conditions. When the system is in the open loop mode, the air/fuel mixture will be based on a predetermined ratio that is dependent on several engine operating conditions.