K11 Owners Group

ken

Old bike did this exact same thing. This one is now doing it too. It warms up, and then starts cutting out. I can usually fight it and get it back, as I didn't get far from the house....but it is like it turns itself off then back on. Running it with the cold start on helps it get home.

I have read a bunch of things and basically have learned that there are 2 temperature sensors on the bike. One is in the radiator fluid, and one is an air temperature.

Which one is the one that controls fuel/motronic?

I can find the one in the radiator but I can't find the air temp sensor. Does anyone have a Picture of this air temp sensor?

Thanks
Ken
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Ken in Denver

Inge K.

SugarHillCTD · Posted: Mon Mar 31, 2014 11:36 am Post subject:

You might have a faulty HES (Hall Effect Sensor).
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John & Cathy

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

Lone Rider of Santa Fe · Joined: 30 Mar 2007 Posts: 18 Location: New Hampshire, USA

Sounds familiar. My problem turned out to be the moronic coolant temp sensor (the spendy one) that threads into the motor immediately behind the radiator. There is a fault code for it. That's how I eventually fault isolated the problem. The sensor would go oc intermittantly and enrichen the mixture to the point where the motor would flood and stall. I confirmed this on my kitchen stove with a pot of water. New sensor $90, 2hrs labor, problem solved. Good luck with your investigation.
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Paul
'96 K11RS "Victor"

Inge K. · Posted: Mon Mar 31, 2014 1:02 pm Post subject:

David_S_Walker · Posted: Tue Apr 01, 2014 7:21 am Post subject:

Tim (Midland Section) · Posted: Tue Apr 01, 2014 6:19 pm Post subject:

Do a search, somewhere on here is a reference to the ohmic values of the temperature sender at different temperatures. I too had a K which died as it warmed up. Never found the fault, as a newer one came along. It seems common for the sensor to get a "hole" in the range, which results in misfuelling.
Similarly a duff HES can be encouraged to fail with a hairdrier.
HTH
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Regards Tim,

Grey haired riders don't get that way by pure luck
1996 Guzzi Cali3 LAPD
1972 750 Commando
G6HRN
#485

Scott_Anderson · Posted: Tue Apr 01, 2014 10:08 pm Post subject:

Flying Duck · Posted: Tue Apr 01, 2014 10:40 pm Post subject:

BobZ(IL) · Posted: Wed Apr 02, 2014 9:24 pm Post subject:

I'm being plagued with the same problem again as well. Last year, after doing the heat gun test and cleaning all connections to no avail, FD suggested renewing heat sink paste on ignition control unit which seemed to work. Did a 5k mile west coast trip without a problem.....well, discounting driveshaft replacement.

Seem to be getting plenty of fuel to the rail so I'll do another heat gun test and check for Inge's sensor fault code. Also going to check ign. control connection for corrosion.

Love riding that bike, but one of these days it's going to quit and I'm going to park it and walk away.
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'93 K1100LT
'78 R100S
'05 R1200GS
BMWMOA, CRBMWOA, ABC, K11OG #997

Live well, do good work, enjoy the ride.

ken · Posted: Fri Apr 04, 2014 6:08 pm Post subject: Still working on it.

I found a couple old links on here as well. It really does act like it is a fuel filter. I went through the list of things mainly because the Hall thingy..is PRICEY and the LAST thing on this list.

"#4 is Crankcase breather tube. they said if there is any cracking it i, this hose allow excess air into the intake that the computer doesn't know about making the bike run lean. The effect is most pronounced at smaller throttle openings."

Well...I opened it up, and sure enough both hoses going to the top of the air box are cracked. I went to BMW and ask for those hoses...they aren't very well described in the parts drawings. They are $50 and they are "guessing" they are those part numbers. If they come in wrong...I still bought them.

Didn't like THAT so thought...I will go look at my parts bike...which incidentally had the same problem just 85,000 miles more than this one when I retired it.....BUT it would do the same thing...breakdown when it was warm... Looked, and these hoses are junk on that one too!!!

I found something online in here titled "Crankcase Breather Mod" Is the reason you would do this simply because you can't find these hoses?

Thanks

Ken
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Ken in Denver

Inge K. · Posted: Fri Apr 04, 2014 9:19 pm Post subject: Re: Still working on it.

ken

It appears it is the Hall Effect Sensor.

This is the second one of these I have lost. One on a bike with 123,000 miles, ( I was third owner, not sure it hadn't failed before)

Now this one with 62,000 miles.

I found one that says it is new OEM from Bosch for $359

1 Used for $160 but having lost two...I am thinking maybe new would be better, I travel on it, and don't really want to be stranded because I didn't spend another $200.

Sent a Tom Wade an email asking about his wire loom kit, what I read on a thread somewhere is that the wire in the loom between the HES sensor, and the wiring harness is typically what fails?

Anybody else heard of this?

Thanks
Ken
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Ken in Denver

hfxrzw · Mad Brick Rider Joined: 30 Jan 2009 Posts: 78

Ken, those sensors themselves aren't too expensive and fairly easy to replace. If you doubt the loom measure it from the sensor to the connector. IHave a look around, there are many guidance docs on the web. The boxers have a similar piece of kit, look at those repairs as well.
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Cheers, Rene

Greetings from Florida.

BMW K100 '85

ken · Posted: Tue May 06, 2014 8:05 pm Post subject: Thanks everyone

It turned out it was the Motronic Unit.

Now to just put it back together, and try to get the rear disc off.

come on gawkers....run some of that gravel out of those mountain roads so we can go have some fun!!!
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Ken in Denver