Idle / Throttle Problem

[pbenoit]

My '04 R1150R seems to have developed an inconsistant idle and a hesitation/miss when getting on the gas in 3rd gear and higher. I did a valve adj and throttle synch recently using a twin-max, but still have the inconsistant idle. The bike idles fine when cold, but once warmed up it will idle at 1100 rpm for 10 to 15 seconds and then start dipping to 900 rpm and rising back to 1100 rpm. It is almost like it missed a squirt of fuel from the injectors and caught itself before it began to stall. Additionally, it has developed a hesitation/miss when rolling on the throttle in 3rd gear and above. It cuts in and out (jerky motion) and won't pull cleanly to redline, but will climb to redline. I don't know if the above problems are vaccum, fuel or spark related. I have 19,000 miles on the bike and have not changed the fule filter or spark plugs yet. I am going to replace them this week and see if this helps. Additionally, I was thinking about removing the rubber vaccum tubes that connect to the bottom side of the throttle bodies, closing off the exposed hole and seeing if the idle smoothed out.....is this a good way to test for a possible vaccum leak in the hoses that connect to the throttle bodies. Thanks in advance for any info / help you can provide. I'd like to try to fix it myself before I bring it to the dealer.

[Capt. Blackadder]

Peter,

Has the oxygen sensor wiring been rerouted on your bike? There was a recall issued by BMW a while back, and that might be your issue. More info here.

[pbenoit]

Thanks Capt B.......I'll check it out tonight.

[Smoothrider]

Have a good look at the "stick" coils that masquerade as plug caps. Mine had corroded badly and swollen and were shorting out causing similar problems to those you have described.

[pbenoit]

Geoff, I plan to replace the plugs this weekend and will inspect the caps in the process.....thanks for the tip.