2011 R1200RT stumbling off idle--maybe winter gas?

[Warland]

Hi all, I am new to camheads but have been riding and maintaining an airhead and an oilhead for years. 

 

Today on my commute home I started experiencing stumbling when pulling away from stoplights and stopsigns (small throttle openings). Bike seems to run OK once underway. 

 

Just adjusted valves and changed out spark plugs over the weekend. Post-service shakedown ride was all good. 

 

Temps spiked to 90 degrees today in Chicago. I remember reading in the airheads lists long ago that winter formula fuel can cause poor running when spring temps spike. Could that be my issue? 

 

Reading this forum it seems the other likely culprit is failing lower coil(s).

 

2011 R1200RT, 33K miles

 

Thanks,

Chris Warland

[dirtrider]

12 hours ago, Warland said:

Hi all, I am new to camheads but have been riding and maintaining an airhead and an oilhead for years. 

 

Today on my commute home I started experiencing stumbling when pulling away from stoplights and stopsigns (small throttle openings). Bike seems to run OK once underway. 

 

Just adjusted valves and changed out spark plugs over the weekend. Post-service shakedown ride was all good. 

 

Temps spiked to 90 degrees today in Chicago. I remember reading in the airheads lists long ago that winter formula fuel can cause poor running when spring temps spike. Could that be my issue? 

 

Reading this forum it seems the other likely culprit is failing lower coil(s).

 

2011 R1200RT, 33K miles

 

Thanks,

Chris Warland

Morning Chris

 

Did the stumbling start after riding in the heat for a while or right after starting to ride off? If it took a while to show up then it could be a fuel "vapor pressure" issue (but that is mostly a carburetor engine deal rather than a high pressure fuel injection issue).

 

It could be a stick coil issue (that is difficult  to find without swapping in a new coil or coils). 

 

See if it acts better on the morning (cooler weather) ride, if so then run that tank of gasoline out then  put some new in.    

[Warland]

Thanks for your reply. 

 

The issue emerged after an hour of hot, stop-and-go urban riding. 

 

After dinner I went out and topped off the tank and rode around for a half hour or so and the stumbling did not present again. 

 

So, maybe a heat-related fuel issue. I'll be prepared to try the coils if it persists. 

 

Thanks again,

Chris