07-02-2020, 03:23 AM
After much trawling on the Japanese forums I found that this is also a known issue in Japan. I would post links to what has been said but they mirror what has been observed here and it's all in Japanese language.
The key takeaway from an official Japan Honda dealer post is a suggestion to have the ECU reset at a dealer. Here is the content translated approximately:
"For PGM-FI vehicles (with clutch switch)
・The idling rotation does not drop to the specified value.
・The idling speed is lower than the specified value.
There are some irregularities in idling rotation.
In such cases, the following measures may be considered.
● Target: PGM-FI vehicles with a clutch switch
● Event: The idling speed may not drop.
Example CB1100EX 1600rpm
●Cause: When the clutch switch is ON (while the lever is being held), the idle speed is reduced due to the half clutch, and the ECU instructs the ECU to open the IACV to restore the idle speed to the standard value. If that state is repeated several times, improper data will be written to the ECU and idling will not drop to the specified value.
●Correspondence: Reset the ECU (re-learn idling) to return the idling to the proper speed."
The key takeaway from an official Japan Honda dealer post is a suggestion to have the ECU reset at a dealer. Here is the content translated approximately:
"For PGM-FI vehicles (with clutch switch)
・The idling rotation does not drop to the specified value.
・The idling speed is lower than the specified value.
There are some irregularities in idling rotation.
In such cases, the following measures may be considered.
● Target: PGM-FI vehicles with a clutch switch
● Event: The idling speed may not drop.
Example CB1100EX 1600rpm
●Cause: When the clutch switch is ON (while the lever is being held), the idle speed is reduced due to the half clutch, and the ECU instructs the ECU to open the IACV to restore the idle speed to the standard value. If that state is repeated several times, improper data will be written to the ECU and idling will not drop to the specified value.
●Correspondence: Reset the ECU (re-learn idling) to return the idling to the proper speed."