Really rich - but can't afford it.

[Staticam]

The bike in question is a 1993 BMW R1100RS.
It has no oxygen sensor or cat.
It does have a c/o pot.
The TPS seems to be in the right place (3.75V). Air and oil temp sensors I think are ok (I can get readings if required).
Air filter is new. Haven't checked the spark plugs.

Once warmed up (and it's a sod till it is) it runs fine, no missing or back firing. It's just drinking the gas. You can smell (unburnt) fuel at idle (esp. when cold, obvious) and when following it.

OK so its running rich (about 7 litres / 100 km). Why?

Worn or dirty injectors. Can these be checked by reasonable home mechanic?
C/o pot not adjusted correctly. Do you need a gas analyser to check and set this?
What else might I be missing?

Do I just cough up and pay a professional to tune it?

I would really like to get this right before the Burt Munro trip in a couple of weeks, any help appreciated, thanks.

[kwaka_crasher]

I'm drawing a blank, but it's late... c/o pot?

7L/100km doesn't seem that much to me. That is 40mpg...

Anyway, am I correct in my understanding that it runs like a bag of crap cold but is ok once warmed up - it just drinks like a fish? Is there any snatching coming off a closed throttle back to cruise, like when coasting to lights and they change to green before you get there?

From what I've found it should be a Bosch Motronic system, which is an L-Jetronic with a digital processor and incorporates EST.

Your TPS should be set at 0.370V - 0.400V ignition on/engine off/throttle closed. Was your 3.75V a typo? If not, that will be your problem.

Otherwise it could be a faulty fuel pressure regulator. Or temperature sensor. Or air flow meter. You really need to find the specfications for all the components.

[BASS-TREBLE]

I can't help sorry, but you may want to ask at www.advrider.com

They deal with Beemers a lot and I bet the 11GS is very similar to your RS as far as layout of electricls go

Good Luck!

[Staticam]

I'm drawing a blank, but it's late... c/o pot?

CO (carbon monoxide) potentiometer.

I can sort of live with the mpg but it should be getting more?. Maybe I'm just not riding far enough into the red light. It's only getting 200kms before the RID goes out and the red light comes on. 14~15 litres to top up.... hmmm, a 23 litre tank. I guess the rest of the kms are hiding in reserve behind that red light.
Popular stats (and who believes them) say 16.6 km/lit (6 litres / km).

The bike is on loan to a friend at the moment. He is saying that it is hard to run smooth at low speed, feels like it is too high a gear? So yes it could be a bit snatch. Is that throttle balance?

Yea, I think my TPS volt reading is a typo... I better check to be sure.

Ah yes, fuel pressure, another thing to check, but I can't do it damn it.

There is no AFM.

The borrower has just said the rear brake has gone. Farrrk. I had a look, as the pedal goes down the fluid level in the reservoir rises. Seals in the rear master cylinder?

[Staticam]

Just reporting back.

I took the bike in for a check and tune. Fuel pressure OK.
When they performed throttle balance they found left throttle bbs had no effect. Some PO had mucked about with the internal butterfly stop. Reset internal stop, tps and bbs's - now correct. CO at 6%, to high. Removed ECU map plug, adjusted tps to get 2.5 to 3%. Starts from cold easily and runs well.

I robbed the rear master cylinder from the Cagiva and set of on my first big trip, Wellington - Invercargill - Wellington. Saw about 300kms for 17 litres and still had a bar or two left on the RID.

Oh yes, I enjoyed the trip, might have to do another.