K11 Owners Group

[Splund]

So my fuel pump died in my 94 K1100LT. I got a replacement from a 2002 R1150GS which uses the exact same pump.Then I thought i'd investigate the cause of the premature expiry of the old pump. As the inlet strainers was burst I though the issue would boil down to the ingestion of crud floating around in the tank.

Here is the R1150GS pump



Now the old pump

Peeled Pump










The brown gunk is not the metal components rusting, its the remains of some grit or grime that was sucked in and ground up to a fine paste jamming the pump. These parts cleaned up nicely (futile given what i'd done to the pump). The tolerance is very close in the large concentric gear and it won't take much to clog it up. The inlet strainer was the same bag type you see on the GS pump and my old one had undone one of its seams letting in large bits of grit n grim. My fuel tank is actually very clean and rust free on the inside so am not sure where these bits came from but there was a small pile sitting directly under the pump.

Th.. th.. the that's all folks!
_________________
"04 Suzuki SV650S (sold)
"94 BMW K1100LTIC

[SugarHillCTD]

Good to know about the cross reference to the R1150 fuel pump.

Had to do a pump replacement after riding to Hungry Mother last year. "Bit the bullet" and bought new from one of the parts guys in the US that doesn't charge full price.
But I want to rehab the old pump and carry it as a spare.
_________________
John & Cathy

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

[Splund]

If you intend to refurb the old pump you should try flushing and letting it soak in some fuel line cleaner. Somebody wrote a post about this and recommended a cleaner. This might have worked in my case if I had more patience and saved me tearing up the old one. To dismantle it as shown in the pictures I ripped open the aluminium casing. I had tried to price it open and slide the parts out but the casing is so soft it simply started to tear so thought heck just tear it apart. If yo have more patience, more skill and the right tools you might be succesfull in sliding the parts out and maintain a good shell casing.

There are other BMW bikes that used the same pump but mounted in different ways. Any fuel injected bike BMW built between 1993 and 2004 have the same pump. They changed around these years so if you have a1993 bike you might have the older style pump. Also from around 2005/06 they started using a different pump design in the other models. Its actually a very similar looking pump but the electrical connections are a plug and socket affair as opposed to the screw terminals on the pump.

Specifically the following bikes built in the year range 1993-2004:
Fuel pump:16141341231
R1100 GS, R, RS, RT, S
R1150 GS, RT, RS
R850 R
K1100 LT, RS
Note that the R1150S does not use this pump.

You should write up a how to, if you find an effective method.

Cheers
_________________
"04 Suzuki SV650S (sold)
"94 BMW K1100LTIC

[Phil Marvin]

Hi, Splund,
As far as the "231" fuel pump goes, you might check with Motobins or Motorwerks (sp?). I know on this side of the pond, Beemer Boneyard sells a replacement for the "231" pump for a LOT less than BMW gets for the OEM pump. As far as the pump and the mounting parts are concerned, the mounting clip is the same for either the old ('83-'92) or new ('93-+) pump. The vibration damper, pump and strainer are different. If you have an old pump, vibration damper and strainer, you can mount them in the mounting clip, install them in your later model bike, and the pump will work fine.
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Ride Safe,
Phil Marvin in El Paso, TX
'94 K75A/3
'95 K75RTP