K11 Owners Group

[SugarHillCTD]

OK folks- can't even sell it if it "ain't" running good, so here are my latest observations.......

1) THE SURGE is back and it is industrial strength now. It ONLY occurs when the throttle is right between accel and decel. Makes for a pretty jerky ride especially on backroads with lots of changing throttle positions. Otherwise it runs strong, accelerates as hard as ever.

2) Today Cathy had her company picnic in the southern part of the state. 2 hours each way. 2/3 was 70mph highway, the rest 30-50mph two lane. We got right about 35mpg- HUH?? I am always around 47-50mpg.

3) When we stopped for fuel (twice due to crappy mileage), the bike stinks, bad.

Anybody vote for oxygen sensor? Or????

Funny thing is that after the clutch job, I rode for 2+ hours with Saltcreek without this happening. Only once Cathy and I rode to dinner later that same day did the bike start to act up. Coincidence?

I'm outta' patience here.......................
_________________
John & Cathy

'92 K100RS4V Pearl White SOLD
'04 K1200GT
IBA Several-SS1k, BBG, 50CC NYC to S.F.

[Flying Duck]

What does it stink like? Sulfur, gas? Couldn't hurt to check the connector on the O2 sensor.

Last fuel filter change?

Are the spark plug leads nice and tight at both ends?



How many bottles of energy drink did you use?
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

[Saltcreek]

I'm starting to be very suspicious of Cathy.
_________________
Jim

1994 K1100LT Mystic Red, bfd, 37000 miles, sold
2009 Wilderness Systems Zephyr 155 ST
2002 Litespeed titanium

[SugarHillCTD]

[Saltcreek]

I just remembered, didn't I say I thought I smelled something like that riding behind you? I think it was on deceleration. We used to have a car that would have a sulfur smell sometimes and I think someone told me it was the catalytic converter.
_________________
Jim

1994 K1100LT Mystic Red, bfd, 37000 miles, sold
2009 Wilderness Systems Zephyr 155 ST
2002 Litespeed titanium

[Flying Duck]

Yes, sulphur "farts" from cars are from the cat.
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

[Flying Duck]

What do you mean by between accel and decel.

I'd replace the fuel filter just for kicks. A 3032 from NAPA will do the trick for about $7.
_________________
93 LT (x2)
94 RS
86-97 K75F(K75/100/1100 Frankenbrick)
86 K75C w/paralever, hi perf cams,TURBO!
91 & 92 K75Ss
91 K1
86 custom K100
14 WR250R
IBA #17739 (SS1K, BBG, 50CC)
Buy parts HERE

[SugarHillCTD]

[whyoldbill]

I had this on my truck one time, it turned out to be a bad O2 sensor.
FI system was dumping excess fuel (explans sucky mileage) which was getting trapped in the catalytic convertor.
I'd say, check that O2 sensor and the connectors between it and the Moronic.

Bill
_________________
'02 - GL1800


The desired effect is what you get when you improve your interplanetary funksmanship - George Clinton

[max]

Don't have an O2 sensor here, but I think they're one wire, right? (definitely not the 4 wire pre-heater jobs - would kill the battery - so I think 1 wire was the only other common Bosch type...)

If it is one-wire, check the muffler itself is grounded, and that the "case" of the O2 is at ground too... If you did the clutch I'm guessing you dropped the muffler, and if that's somehow stopped the O2 sensor having a good earth return path (guessing sensor - muffler - headers - exhaust header bolts - cylinder head - frame) then it's going to make it go screwy. The sensor only puts out 1v or so (if I remember right, might be less) so resistance isn't good.

Might not be anything like this, but might be worth bearing in mind too. Good luck; only other thought was to check the readng at the O2 connector and then check it at the pin going into the Motronic at the Motronic's plug to make sure nothing screwy there either.

HTH

Max

[SugarHillCTD]

THE PLOT THICKENS..............

Did the pin 1 ground to read the "brain" (the bikes, not mine- mine is already fried from all this nonsense).

It reads out: 2341 (Oxygen sensor at limit) 2343 (mixture setting at limit) Gotta' check those connections again- thanks Max.

I'll be back.......................
_________________
John & Cathy

'92 K100RS4V Pearl White SOLD
'04 K1200GT
IBA Several-SS1k, BBG, 50CC NYC to S.F.

[Saltcreek]

I'm hoping to learn something from John's misery.

What is the function of the oxygen sensor?

Is what's been referred to here as the throttle position sensor the same as what Clymer calls the throttle butterfly potentiometer?
_________________
Jim

1994 K1100LT Mystic Red, bfd, 37000 miles, sold
2009 Wilderness Systems Zephyr 155 ST
2002 Litespeed titanium

[max]

The O2 sensor gives the Motronic EFI system realtime feedback on how well it's predicting the amount of fuel the engine needs - it can tell when there's no free O2 in the exhaust gas, so once that point is crossed the EFI knows it's running rich, so it can then shorten the injector pulse durations (the "width") and lean out the mixture until the O2 **just* comes back. It's a heavily depended on sensor as it's checking the real chemicals, not guessing on mechanical parameters which can drift over time or with faults.

It's part of the EFI modes - which are usually either

1) open -loop, where no feedback is taken into account, and injection amounts are derived from a pre-calculated "graph" correlating degrees of throttle opening to injection duration

2) closed-loop, where the system uses the map as a starting basis (safe guess?) but then tweaks it with real-world physical feedback from YOUR engine - ideally from the combustion process, which is where the O2 sensor comes in.

If the system has an 02 sensor but then "fails over", usually they over-compensate the fuel rates to ensure the safety of active components (turbos, cats) in the exhaust - rich won't help, but won't melt anything either.

PS - the TPS varied on the Ks because

K100s 2v used LE-Jectronic an analogue system. Air mass is measured on a varying electrical scale by the calibrated airflow meter in the top of the airbox. The TPS then was a **switch** to turn on an "idling now" mode (I guess to reduce scales on the AFM to reduce idle surging).

K1100s / K100 4vs use Motronic - computerized. The air mass is looked up on an internal map from precalculated constants (throttle degrees open, throttle venturi size, cylinder CCs, incoming air temp to give density, RPMs, etc). The TPS is then a sensor with varying output to precisely locate the throttle opening.

A varying electrical voltage proportional to movement is usually created by a potentiometer, so yes, the TPS is the "throttle butterfly potentiometer"! <grin>

PPS - in reality, there are a set of maps, depending on how fancy the system is and how tuned the engine is... they might also use other metrics, eg engine temp as a curve, rather than "engine cold, engine hot", gear your in, rate of change of throttle (fast open = accelerate, fast close = decelerate, stop injection, watch for stall conditions), "knock" present (from a peizoelectric pseudo-microphone "listening" for it). If you go REALLY fancy, you also now get spark duration feedback (so the system can account for wearing plugs & varying mixtures - which affect how easy it is for the spark to "strike") and individual O2 sensors for each cylinder (great for catching runaway injectors before they cause a turbo/cat nuking backfire).

Confused yet? Wait till you go over integration of automatics, 4Wd, traction control, ABS & ESP...

Cheers

Max

[SugarHillCTD]

Jim,

On Friday I had to ride 45 min north for some family related business. On the way I made a few stops and did a few TPS adjustments. Before I started, the TPS setting was about at the middle of the available adjustment.
Tried slight counter clockwise adjustment (looking from back to front) No difference.

Then tried clockwise- BAD results.

Tried pulling the TPS plug and riding with it disconnected. REALLY bad running.

BTW, it looks like gaining access to the TPS internals means doing some cutting to get to the internal

I just want to gas and ride.

Will get a new gas filter in the next few days.

John

I have an O2 sensor coming from BeemerBoneyard by mid-week.
_________________
John & Cathy

'92 K100RS4V Pearl White SOLD
'04 K1200GT
IBA Several-SS1k, BBG, 50CC NYC to S.F.

[max]

[SugarHillCTD]

Max,

Thanks for the input. I'm determined to work my way through this.

I am working my way up to speed.

Don't want to sound too ancient, but....I was roadracing back in the late 70's and Cathy was my pit crew. She was in charge of carburation ("jets up one or two sizes?"). NOT which programming map to load.

New Beemerboneyard O2 sensor will be here in a couple of days. Will look into a new fuel filter tomorrow or Tues. Did new fuel line today (supply line was looking somewhat kinked and was showing some cracking when I flexed it).

SOMETHING has got to fix this.

Thank you to all those that are giving input to the fix for this. I am convinced that it is possesed. It may go to MaxBMW for an extended exorcism.

John
_________________
John & Cathy

'92 K100RS4V Pearl White SOLD
'04 K1200GT
IBA Several-SS1k, BBG, 50CC NYC to S.F.

[Saltcreek]

Thanks to Max for making this sound a little less obscure.

I maintain that it's too much of a coincidence that this started right after you had the bike split. There has to be a connection.
_________________
Jim

1994 K1100LT Mystic Red, bfd, 37000 miles, sold
2009 Wilderness Systems Zephyr 155 ST
2002 Litespeed titanium

[SugarHillCTD]

I definitely agree. Something was changed by the overhaul.

BUT you smelled my exhaust "stink" before I did the clutch. However it was not surging then.

BTW, I do not hear any "click" from the TPS when I move the throttle off of idle- as many state should be heard. On an 1100, should I hear it?
_________________
John & Cathy

'92 K100RS4V Pearl White SOLD
'04 K1200GT
IBA Several-SS1k, BBG, 50CC NYC to S.F.

[Flying Duck]

[SugarHillCTD]