Idle Vibration

[Buster]

Engine vibration at idle came up in another thread but my experience is a little different, so.....

 

I picked up my '05 RT from it's 600 mile service last night and was amazed at how much vibration it exhibited at low rpm's. Normal running rpm's were just fine but the beast just didn't want to idle and it actually conked out on me once in traffic when I rolled off all the throttle quickly and pulled in the clutch. Because it was running just fine at normal speeds, I went ahead and took it on home but it never got better during the trip.

 

I now know what that guy in the other thread meant when he said; "she shakes like an epileptic crack-whore." (no offense intended to people with epilepsy or to crack-whores)

 

This morning I started the the bike and it ran much smoother; maybe almost back to normal (whatever normal is for a HexHead). At lunchtime I took it out for a ride long enough to get the motor up to normal operating temp and it seems fine - idling at about the same level of vibration as always.

 

During the 600 mile service visit the battery was disconnected to install some accessories.

 

I called my dealer, who seems to be more knowlegeable than most, and he confirmed my suspicion that there is a computer of some sort somewhere in the engine management system that "learns" or adapts to engine operation and he suspected that the battery disconnect had reset this computer to some non-normal condition. He suggested that the computer would correct itself with a little use and to let him know if it did not.

 

Anyone have a similar experience or any insight into this (hopefully one-time and temporary) gremlin?

 

Thanks

[FIRST_BEEMER]

Yes the ECU theory sounds right.

Some ECU`s can loose memory and need to relearn IAC (idle air control) and TPS (throttle position sensor) min air rate settings after power has been removed long enough to clear the memory. Base idle and IAC counts are a balance for idle control (ECU vs IAC vs min air rate) to allow base idle range (rpm`s) to to meet all the calibration presets for the ECU`s base information and (program read only memory) prom data.

[Ken H.]

You have to re-train the EMC to the throttle position sensor after the battery has been disconnected.

 

Turn the key on but do not start the bike. Bike in neutral, cut-off switch in run.

 

Rotate the throttle through it's entire range twice.

 

Start the bike.

 

I can't believe the dealer didn't know / do this. It's in the owners manual. RTFM applies.

[Buster]

Oops! now that you mention it I believe I did read that somewhere but my eyes glazed over. Heck, I can hardly remember where the key goes some days.

 

Thanks for the info - I'll pass it on to the wrenches in the shop.