Author Topic: Fun and Games with an old K1100LT  (Read 15987 times)

Offline beemuker

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Re: Fun and Games with an old K1100LT
« Reply #75 on: April 30, 2021, 09:54:23 AM »
Shouldnít I be getting 12 V at the tank connector yellow wire?
  • Panama City, FL
  • '00 R1100RT,í92 K75 RT,past tense:'83 R80ST, '93 K1100LT,,94 R1100RS K75s, Honda NC700, Suzuki Bandit 1200, bmw R75/5 Honda 750

Offline daveson

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Re: Fun and Games with an old K1100LT
« Reply #76 on: April 30, 2021, 09:58:14 AM »
I don't see yellow on the drawing, I'd just Focus on power and earth.
  • Victoria, Australia
  • Current;'85 K100RT~100,000km; four other bricks. Past; 1500 Vulcan, V Star 650, KLX 250(dirt bike) TT250(dirt bike)

Offline beemuker

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Re: Fun and Games with an old K1100LT
« Reply #77 on: April 30, 2021, 10:01:49 AM »
I don't see yellow on the drawing, I'd just Focus on power and earth.
there are four wires going into the tank white green yellow and brown I believe Brown is the earth the white and green are fuel level and low fuel and I believe the yellow is the power to the pump shouldnít I be getting 12 V to the pump on the yellow wire?
  • Panama City, FL
  • '00 R1100RT,í92 K75 RT,past tense:'83 R80ST, '93 K1100LT,,94 R1100RS K75s, Honda NC700, Suzuki Bandit 1200, bmw R75/5 Honda 750

Offline daveson

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Re: Fun and Games with an old K1100LT
« Reply #78 on: April 30, 2021, 10:18:15 AM »
You might be right. Trace back to find where the Voltage drop is. Maybe the relay.

Just signing out nigh on midnight here, got to get to bed before my car turns into a pumpkin.
  • Victoria, Australia
  • Current;'85 K100RT~100,000km; four other bricks. Past; 1500 Vulcan, V Star 650, KLX 250(dirt bike) TT250(dirt bike)

Offline beemuker

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Re: Fun and Games with an old K1100LT
« Reply #79 on: April 30, 2021, 11:03:09 AM »
there are four wires going into the tank white green yellow and brown I believe Brown is the earth the white and green are fuel level and low fuel and I believe the yellow is the power to the pump shouldnít I be getting 12 V to the pump on the yellow wire?
can anyone confirm this for me which wire at the tank connector supplies power to the pump I think itís the yellow but Iím not sure
  • Panama City, FL
  • '00 R1100RT,í92 K75 RT,past tense:'83 R80ST, '93 K1100LT,,94 R1100RS K75s, Honda NC700, Suzuki Bandit 1200, bmw R75/5 Honda 750

Offline beemuker

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  • Posts: 1110
  • Panama City, FL
  • '00 R1100RT,í92 K75 RT,past tense:'83 R80ST, '93 K1100LT,,94 R1100RS K75s, Honda NC700, Suzuki Bandit 1200, bmw R75/5 Honda 750

Offline beemuker

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Re: Fun and Games with an old K1100LT
« Reply #81 on: April 30, 2021, 11:35:21 AM »
can anyone confirm this for me which wire at the tank connector supplies power to the pump I think itís the yellow but Iím not sure
I think itís the green /wh, when I have the kickstand up ignition on and start depressed I get 12 V at the Green/WhiteSo I think my problem is with the fuel level sending wires
  • Panama City, FL
  • '00 R1100RT,í92 K75 RT,past tense:'83 R80ST, '93 K1100LT,,94 R1100RS K75s, Honda NC700, Suzuki Bandit 1200, bmw R75/5 Honda 750

Offline rbm

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Re: Fun and Games with an old K1100LT
« Reply #82 on: April 30, 2021, 11:43:20 AM »
can anyone confirm this for me which wire at the tank connector supplies power to the pump I think itís the yellow but Iím not sure
Yellow has nothing at all to do with fuel delivery.  It is connected to the variable resistor in the fuel sender and outputs a resistance based on the level of fuel.  If you are reading a voltage, it is parasitic.

Power to the pump is Green/White.  Return for the pump is Brown.  Those are the only two wires you should concentrate on diagnosing.
  • Regards, Robert
Toronto, Ontario

1987 K75 - Build Blog @http://k75retro.blogspot.ca/

Offline Laitch

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Re: Sources for fuel pump?
« Reply #83 on: April 30, 2021, 11:45:23 AM »
I think itís the green /wh, when I have the kickstand up ignition on and start depressed I get 12 V at the Green/WhiteSo I think my problem is with the fuel level sending wires
. . . I tested continuity between the ground coming from the 4 pin to the ground on fuel pump and the power from 4 pin to pump. both have continuity.
Doesn't the second quote above indicate that there is continuity between the plug and the pump so there should be no problem?
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline rbm

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Re: Fun and Games with an old K1100LT
« Reply #84 on: April 30, 2021, 11:54:10 AM »
Looking at the wiring diagram if Iím getting power at the green white on the fuel pump relay I should be getting power to the fuel pump unless unless the other wire going to the motronic can keep it from getting power somehow
If you are getting power to Green/White at the fuel pump relay, you should also be seeing power at the Green/White lead on the harness side of the tank connector.  There are no wires to the Motronic that should interfere with this power path.  The L/Br wire to the Motronic is a switched ground but you've already proven that the Motronic is working correctly, the fuel relay is working correctly, and the power supply to the fuel pump is working correctly.  There should be nothing in the way of getting the fuel pump to operate except if there is a break in the wiring somewhere between the harness side of the tank connector and the tank itself.  That could be :
- tank connector defective
- tank wiring to fuel pump defective
- gas tight passthrough on the fuel sender defective
- solder joints inside the tank to the passthrough defective
- fuel pump defective

That's quite a list but can you check these items off and confirm they are intact?
  • Regards, Robert
Toronto, Ontario

1987 K75 - Build Blog @http://k75retro.blogspot.ca/

Offline beemuker

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Re: Fun and Games with an old K1100LT
« Reply #85 on: April 30, 2021, 01:52:19 PM »
If you are getting power to Green/White at the fuel pump relay, you should also be seeing power at the Green/White lead on the harness side of the tank connector.  There are no wires to the Motronic that should interfere with this power path.  The L/Br wire to the Motronic is a switched ground but you've already proven that the Motronic is working correctly, the fuel relay is working correctly, and the power supply to the fuel pump is working correctly.  There should be nothing in the way of getting the fuel pump to operate except if there is a break in the wiring somewhere between the harness side of the tank connector and the tank itself.  That could be :
- tank connector defective
- tank wiring to fuel pump defective
- gas tight passthrough on the fuel sender defective
- solder joints inside the tank to the passthrough defective
- fuel pump defective

That's quite a list but can you check these items off and confirm they are intact?
I removed the fuel level sender, spliced  new wires to the yellow and black going to pump. obvious which is ground and which is hot.
with stand up switch on, button depressed cranks and  , I get 12 v from g/w harness side.
I do not get power at pump, but I checked continuity from tank side connector, both g/w amd ground, and both check continuity.
  • Panama City, FL
  • '00 R1100RT,í92 K75 RT,past tense:'83 R80ST, '93 K1100LT,,94 R1100RS K75s, Honda NC700, Suzuki Bandit 1200, bmw R75/5 Honda 750

Offline rbm

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Re: Fun and Games with an old K1100LT
« Reply #86 on: April 30, 2021, 02:04:52 PM »
It's a defective connector.  Have you replaced the connector?  If not, take a flat blade jewellers screwdriver and deform the female contacts on the harness side to make them slightly smaller.  This will improve contact to the male pins.
  • Regards, Robert
Toronto, Ontario

1987 K75 - Build Blog @http://k75retro.blogspot.ca/

Offline beemuker

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Re: Fun and Games with an old K1100LT
« Reply #87 on: April 30, 2021, 02:06:28 PM »
Can you take the components (pump and sender) out of the tank and test the setup outside of the tank?  This will allow you to make electrical tests without the risk of sparks and fire.
already did that. I get continuity on wires to fuel pump from tank side of connector. I get 12 v at harness side of connector, but no power when everything is connected measuring v at pump. Doesn't make sense, what am I missing. ?
  • Panama City, FL
  • '00 R1100RT,í92 K75 RT,past tense:'83 R80ST, '93 K1100LT,,94 R1100RS K75s, Honda NC700, Suzuki Bandit 1200, bmw R75/5 Honda 750

Offline beemuker

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Re: Fun and Games with an old K1100LT
« Reply #88 on: April 30, 2021, 02:08:07 PM »
It's a defective connector.  Have you replaced the connector?  If not, take a flat blade jewellers screwdriver and deform the female contacts on the harness side to make them slightly smaller.  This will improve contact to the male pins.
thanks, I'll try that next after I refuel.
  • Panama City, FL
  • '00 R1100RT,í92 K75 RT,past tense:'83 R80ST, '93 K1100LT,,94 R1100RS K75s, Honda NC700, Suzuki Bandit 1200, bmw R75/5 Honda 750

Offline beemuker

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Re: Fun and Games with an old K1100LT
« Reply #89 on: April 30, 2021, 03:08:57 PM »
it appears to be the connector. inserted wires into the female connector and clipped leads on the male grn/wh and brn and started, fuel pump whirred . going to get a female flat trailer connector[have several male and I should be good to go. will post results. thanks for all the help .
  • Panama City, FL
  • '00 R1100RT,í92 K75 RT,past tense:'83 R80ST, '93 K1100LT,,94 R1100RS K75s, Honda NC700, Suzuki Bandit 1200, bmw R75/5 Honda 750

Offline beemuker

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Re: Fun and Games with an old K1100LT
« Reply #90 on: April 30, 2021, 09:36:12 PM »
One of my neighbors had the other half of the trailer flat connector. Cut out the old connector and spliced in and shrink wrapped the new one. Got the tank back on, poured some non corn in, and after the second try she started up. Took er for a spin and after all the trials of cleaning out the tank innards and wires it was a satisfying short ride.
Still lots to do but I knew that going in and the price was right.
ABS not working .
Forks weeping and contaminating brake rotors and pads.
Oil around weep hole.
Needs tires

But,
The paint and luggage are in good shape.
Clutch doesn't slip
Locomotive power.
Surprisingly nimble for such a heavy bike
Nice color [683] gruen met [metallic green?] I'll post some pics when I clean the old girl up

I found a fuel level sender for $100 . Was going to live without it for 300, but $100 seems reasonable.I cut off the sender and spliced wires on the old one in the meantime. 

Thanks for all who chimed in ,I learned a lot from you inmates.
I owe RBM, Laitch, Gryph, Daveson, etc. a few beers and a nice fresh caught fish dinner when you're in the neighborhood. [The boats running great too,we can catch dinner]


  • Panama City, FL
  • '00 R1100RT,í92 K75 RT,past tense:'83 R80ST, '93 K1100LT,,94 R1100RS K75s, Honda NC700, Suzuki Bandit 1200, bmw R75/5 Honda 750

Offline beemuker

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Re: Fun and Games with an old K1100LT
« Reply #91 on: May 02, 2021, 09:09:50 AM »
Rode the brick around town yesterday, and the moto ran great EXCEPT the right fork seal is not just weeping, it is gushing fork oil, which makes the front brake rotor well lubricated. Ordered new brake pads as the current ones are saturated. On to fixing the fork seals, another task I've never had the pleasure of tackling.
The seals and caps are about $50 from Max and A&s. I found an old post referencing Marzocchi part 528134 and they are available from various sources for $26.
Euromotoelectrics seems to have various enduralast seals that may work, but I'm unsure of which to order from them. I'm not too sure of the Marzocchi as they appear to be for bicycle suspension. Since the labor is going to be the primary cost in sweat, or $ if I pay to have it done, am I best off buying the BMW parts. I think they are Marzocchi forks though.
https://www.amazon.com/gp/product/B07BR67H6J?pf_rd_r=3PC8J8PBKQB7J9462NK1&pf_rd_p=5ae2c7f8-e0c6-4f35-9071-dc3240e894a8&pd_rd_r=5df0f6a9-c935-439b-bbfc-89f878fb88da&pd_rd_w=Be4Rp&pd_rd_wg=rWXH5&ref_=pd_gw_unk
  • Panama City, FL
  • '00 R1100RT,í92 K75 RT,past tense:'83 R80ST, '93 K1100LT,,94 R1100RS K75s, Honda NC700, Suzuki Bandit 1200, bmw R75/5 Honda 750

Offline Laitch

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Re: Fun and Games with an old K1100LT
« Reply #92 on: May 02, 2021, 12:04:02 PM »
Those are bicycle parts in your link.
Get fork tube seals from BMW; should be close to that price. MaxBMW has them.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline The Mighty Gryphon

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Re: Fun and Games with an old K1100LT
« Reply #93 on: May 02, 2021, 12:25:28 PM »
Look for posts here referring to fork seal cleaning.  It's a good chance you just have a piece of crap stuck in the seal.
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline beemuker

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Re: Fun and Games with an old K1100LT
« Reply #94 on: May 02, 2021, 05:27:36 PM »
Look for posts here referring to fork seal cleaning.  It's a good chance you just have a piece of crap stuck in the seal.
That was the first thing I did. I had read about the thin plastic "cleaning tool"and made one out of a plastic jug. One of the seals looked rusty and had pieces of rust lying on top. I flushed it out and did the cleaner, but I guess with all that grit it chewed the rubber seal. I just hope the tubes aren't pitted/scored.
  • Panama City, FL
  • '00 R1100RT,í92 K75 RT,past tense:'83 R80ST, '93 K1100LT,,94 R1100RS K75s, Honda NC700, Suzuki Bandit 1200, bmw R75/5 Honda 750

Offline beemuker

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Re: Fun and Games with an old K1100LT
« Reply #95 on: May 02, 2021, 05:33:54 PM »
Those are bicycle parts in your link.
Get fork tube seals from BMW; should be close to that price. MaxBMW has them.
I'll be in CT next week. about an hour away from Max.  I may go pick them up. the caps look good, but it has been recommended that I replace them while I'm at it. If I can get it apart before I go, I'll know better what I need.Too bad I won't be there for the demo event in June  but it still  it would be nice to see some of the new BMWs, even if I can't ride them.
  • Panama City, FL
  • '00 R1100RT,í92 K75 RT,past tense:'83 R80ST, '93 K1100LT,,94 R1100RS K75s, Honda NC700, Suzuki Bandit 1200, bmw R75/5 Honda 750

Offline The Mighty Gryphon

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Re: Fun and Games with an old K1100LT
« Reply #96 on: May 02, 2021, 08:28:39 PM »
Replace the seals and get Rancho #RS1952 Shock boots to replace the caps.  Those Rancho gaiters do an incredible job protecting the seals from the crap that's out there trying to tear them up.  They're one of the best mods you can make to your bike.  I have them on all my bikes.

https://www.ebay.com/itm/142553477350?epid=215134284&hash=item2130d970e6:g:2pEAAOSwuDVecTAP
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

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