CB1100 Idle speed instability problem

[dave]

So I took the bike when I went to dinner last night. About 5 miles of freeway, and three red lights (each way). The engine had plenty of time to reach operating temperature, but the idle was a perfect 1,050 RPM. This problem sure has me challenged! I'm thinking that maybe something in the way the IACV works is causing it to stick, and not function properly. Does anyone out there understand what controls the input to the IACV, and maybe how it functions? I am convinced that the engine operating temperature has something to do with it because when I unplug the Engine Oil Temperature (EOT) sensor when the idle goes to 1,500 RPM the engine returns to 1,050 RPM. Maybe the EOT sensor is sending a wrong signal to the ECU telling it that the engine is cold and therefore adjust the IACV to increase the idle speed? But I replaced the EOT sensor and this did not fix the problem. I'd replace the IACV, but another member reported that he did this and it did not correct the problem. I'm going to take it out to the desert and make another WFO run to see if this works again, as soon as I get a chance.

I wonder if there is some sort of planned obsolescence issue going on. As if something in the IACV is not designed to go beyond X miles.

My bike started this behavior around 7K mileage. Anyone else?

I think my problem started around 8k miles also.