03-21-2018, 12:25 AM
(03-21-2018, 12:16 AM)Dave_imp Wrote: Update. I performed a test suggested by Max, and here are the results: I unplugged the connection to the IACV and rode the bike yesterday. The temperature was 58 degrees, and the bike had not been started in 24 hours. The engine started normally, and idled at about 700 RPM initially. I’m not sure if it would have stalled if I allowed it to idle by itself, but I warmed it up for about two minutes by gently blipping the throttle before going for a test ride. I rode about three miles of stop and go on city streets and as the engine temperature rose, so did the idle RPM. It reached a steady, smooth idle of about 950 RPM before I turned it off, and there was no indication that it would stall. I let the bike sit for about one hour before restarting, and then took it for a longer ride that included stop and go, and about three miles on the freeway. The engine was fully warmed up on this ride, and it settled into a nice, smooth 1,000 RPM idle. There was no indication of stalling, and it never dipped below 1,000 RPM when allowed to idle. I do believe I felt a slight loss in power (very slight), but other than that, the bike ran perfectly. The idle was smooth and repeatable at every stop, it never dipped below 1,000 RPM, and the engine never missed a beat. This test was performed under cool conditions, so I don’t know if it would be repeatable under more severe (hotter, more stop and go) conditions.
On another note, my bike has never experienced the increased RPM when in 1st gear, as the clutch is being let out, as described by other members. Probably 90% of the time I wait until I feel the clutch begin to engage before applying any throttle, so I believe I would have noticed this condition if it was present. This new idle condition described by some members is interesting, and I we can find out if our bikes are designed to do this.
With this information does Dave now have "probable cause" that the IACV is the culprit?