Running rich - what to check first?

[Orinoco]

My 1100GS seems to be running rich, very sooty exhaust exit, smoked quite a lot on start up and a whiff of petrol. Bike also seems to surge more than usual up to 2500 rpm.

Anything I can check with limited mechanical skills or best to book in? If need to book in, something my local bike shop could do or a BMW dealer needed

Help

Cheers

 

[mikeyboy]

First thought would be air temp sensor

 

[Steptoe]

Does your 1100 have a CO pot ? If so you can adjust the mixture using the screw adjuster .

 

[Uncle-Fester]

Air filter would be the first thing to check, and it's housing, also the air intake pipe.??

 

[Orinoco]

Ah, it does have a CO2 pot, forgot to add that I adjusted a few months ago as per GSJohn's notes when I changed the chip, though that was about 7,000 miles ago and had been running fine.

Thanks

 

[Roger 04 RT]

To set the CO Pot properly, you need a carbon monoxide probe in the exhaust. With one of John's chips you may have too much fuel at small throttle angles but you can reduce it to 2.5-2.0% CO with a probe and gauge. Those values of CO will set your idle AFR to 13.5:1 to 13.8:1, which is a good idle AFR. Not sure who, if anyone, in your area would have one.

Btw, the effect of the CO pot is limited to the first several degrees of throttle rotation only. You can read about that starting at post 848073 here: http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=848073.