HELP! 04 R1150RT Engine Idling Low

[Don M]

My 04 R1150RT has been idling low for the last couple thousand miles so figured a tuneup is in order. Adjusted the valves, installed new plugs, and air filter. Checked for debris under the throttle cables, unscrewed both of the big-brass-screws and cleaned up the seats and screws. Brought the engine up to temp and attempted to adjust low speed idle using my trusty carb stix. Got it balanced but can't get the idle up above 1K. Did a high speed balance but RPM at idle are still low and the bike is stumbling a bit. Now this is where it gets goofy. I pulled the right stick coil and there is no change in the engine operation. Pulled the left stick coil and the engine nearly dies so I figure it's a bad coil. I switched coils from right to left cylinders and get the same result....no change in engine operation with right coil disconnected and the engine dies when I pull the left coil. I checked the coil leads and the pins look just fine. Went to BMW and bought a set of over-priced plugs to replace the new Autolite and Champion plugs I had just installed....still got the same problem. I pulled the right injector and can see a fine mist when I crank the engine but it looks like an awfully small volume....not sure how much there should be as this is the first time I've check the injectors. The bike has nearly 60,000 miles on it, I've never run injector cleaner through it but I run Chevron gas or ethanol free gas most of the time.

 

I'm stumped.

[roger 04 rt]

A couple thoughts come to mind:

 

Your secondary left hand coil wire might be bad. Therefore when you pull the left primary, it dies. But when you pull the right primary it still runs on the right secondary.

 

Did you disconnect the battery or fuse 5 during your tune up? If you did then you lost the adaptive values in the motronic. You will need to relearn the tps And ride the bike a while before setting the idle.

 

If you suspect an injector (I don't) you could swap them side to side but I'd save that test for later.

 

I'm sure you'll get some other ideas soon.

RB

[Tobias]

makes me wonder about the condition of the wiring harness to the right stick coil.

[Don M]

Thanks guys. Still puzzling over this. I pulled the right primary plug, put it in the stick coil and cranked the engine over with the plug shorted out against the head....got a very strong spark so I think the wiring to the stick coil is good. I'm going to do this with the other three plugs soon as I've had some coffee.

I pulled both injectors last night, cranked the engine and I think there is about the same amount of fuel coming out of each injector....maybe less from the right one. The spray is so fine it's hard to tell.