K11 Owners Group

scottisha · Joined: 05 Mar 2013 Posts: 12 Location: Australia

K1100LT 1992- Led to believe that a faulty temp sender module is hiding in water pump, but inspected the thing, no sender. Does this mean only one sender unit, in-line to radiator top hose? In which case I wonder why it has run fine, but just had no fan or gauge? Temp is supposed to inform the Motronic's mixture adjustments, no? Pissing me off enough to just wire it to a manual switch. Manuals are less than expansive on the subject and diagnosis of possible sender issues. If u know something, please advise. Really would like a ride at the moment. ta
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Scottisha
k1100LT still workin on it
RF900R, fast is nice
XJ600, project, rustbucket

Grunter · Posted: Fri Apr 17, 2020 6:39 pm Post subject: Water Pump

Like all K Models K75.K100, K1100 they are on the lower front of the engine below the chain case. The temp sender is on the right hand side low down. The cable just pulls off.

Are you sure it is the sender that is faulty? The cable connector is under a rubber boot and they can deteriorate so much so they don't send any info to the temp gauge.

If you need to remove it, you will have to drain the cooling system. Beware that if you do decide to remove it, because they are in such an awkward position make sure you have a good fitting wrench.
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1997 K1100LT
1994 R1100RS

Flying Duck · Posted: Fri Apr 17, 2020 7:15 pm Post subject:

When putting the temp sensor back into the bottom of the water pump don't overtorque it. It doesn't take a whole lot of torque to destroy it.

9 Nm is the factory torque spec for it.
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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

scottisha · Joined: 05 Mar 2013 Posts: 12 Location: Australia

OK, thanks guys for help. Got the little sucker. Surprised to find it sits in a bath of oil though, given proximity to water pump. So, to summarise, the sender from the coolant circuit sends info to Motronic for fuel management. The sender below and to the right of the water pump provides info to the temp gauge and to motronic, to turn on fan. How did I go? ta
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Scottisha
k1100LT still workin on it
RF900R, fast is nice
XJ600, project, rustbucket

Scott_Anderson · Posted: Mon Apr 20, 2020 6:06 am Post subject:

Not quite... The temperature sensor in the coolant riser pipe(sets behind the radiator on the top of the engine) sends signal to the motronic for fuel control and fan control both.

The temp sensor on the bottom of the water pump sends signal to gauge only.
There are 2 sensors on the water pump.... the forward one(closest to front tire) is for the water temp gauge. The sensor closest to the engine is for the oil pressure lamp in the inst cluster.
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Ride safe.

1995 K1100LT 0302044
1997 R1100RT ZC62149
2017 FLHTK Ultra Limited
Garmin StreetPilot 2820
Garmin Zumo 550
Garmin Zumo XT
"One who does not ask questions is ashamed to learn" Danish proverb
1997 K1100LT 0302488(R.I.P.)

Flying Duck · Posted: Mon Apr 20, 2020 6:19 pm Post subject:

And just to be anal retentive: The oil pressure thingy is a switch, not a sensor. Very Happy

_________________
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

scottisha · Joined: 05 Mar 2013 Posts: 12 Location: Australia

Thanks to Scott and Swamphen. Things are many times clearer. TY. So I am up for 2 x $100 in sensors if I want thje motronics happy and the gauge running. Remember, I lost the gauge and the fan - 2 separate systems? Ah, I will just replace both sensors (due anyway surely), test the thermostat, new gasket, put it back together with fresh coolant. Must get manual fan switch too, don't suppose anyone knows which tag of relay to put this on?
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Scottisha
k1100LT still workin on it
RF900R, fast is nice
XJ600, project, rustbucket

Jim · Posted: Tue Apr 21, 2020 12:05 am Post subject:

I think your answer is here:

https://k11og.org/forum/viewtopic.php?t=13239&highlight=fan+switch

Look at the last post in the thread.
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Jim
1997 K1100LTSE 94,000 - has gremlins!
1995 R100RT Classic 16,650 crashed - repairing
1992 K75RTP 46,000

"We shall not all die, but we shall all be changed."

Flying Duck · Posted: Tue Apr 21, 2020 4:45 am Post subject: Re: temperature sender