CB1100 Idle speed instability problem

[dave]

Gentlemen: I've been doing some research on ECM part numbers and discovered that not only has the ECM part number been superseded, but different Honda CB1100 models used different part numbers for the same year.

I believe the reason for the different ECM part numbers used for the same year is because the Standard (single pipe) and the Deluxe (two pipe) models required different parts. Can someone please explain why this is so? Partzilla identifies the different models using a model designation: CB1100SA AC (Deluxe?) versus CB1100AC (Standard?). Chaparral Motorsports uses VIN numbers to differentiate between the two models.

Chaparral identifies the old, and superseded part numbers for year 2014:
VIN JH2SC658-EK000001: OLD 38770-MGC-A73 NEW 38770-MGC-A74
VIN JH2SC651-EK100001: OLD 38770-MGC-A42 NEW 38770-MGC-A43

I just visited the Partzilla website, and for the 2014 model they do NOT list a superseded part number. I assume that if you place your order with Partzilla for the old part number they will automatically update it with the superseded part number.
CB1100SA-AC: 38770-MGC-A73
CB1100 AC: 38770-MGC-A42

I also discovered on the Partzilla website that the ECM part number for the year 2017 model(s) CB1100CA AC - CB100CA is: 38770-MGC-A41.

I apologize if this information has been shared previously, but as I was reading through the most recent posts I became confused with the part numbers identified, and had to verify for myself. Your comments and clarifications are most welcome.