1/84 K100RS Cannot remove fuel pump :Stuck ? - K-Bikes.com - Excellence in Motion
LinkBack Thread Tools Display Modes
post #1 of 5 (permalink) Old Aug 16th, 2011, 5:54 am Thread Starter
Join Date: Aug 2011
Location: Adelaide, S.A., Australia
Posts: 4
1/84 K100RS Cannot remove fuel pump :Stuck ?


I am trying to bring to life a very early K (0013425). It has spent nearly all it's life unused, 16,000Kms recorded and the tools still wrapped in brown paper. It actually looks good from a distance - the silver paintwork is in excellent condition - no scratches but the rest of it was a celebration of aluminium oxide.
I have spent a month or two cleaning it up. I had the fork legs re chromed, and regreased the head bearings and am now moving towards starting.

With a fuel pump I am hoping it will run

The tank has clearly had water in it. I cleaned it out and partially filled it with diesel and powered the pump externally... I think I was being optimistic expecting anything...but it did growl ..but no pumping. It was pulling about 3 or 4 amps. The terminal posts and all the retaining nuts were rusty but the diesel lubricated them, and all but one came off easily... the last nut eventually freed up with a bit of work. Now all the retaining nuts have been removed I CANNOT BUDGE THE PLASTIC RING. Everything looks normal in there - its not a big mess - I don't know why it will not move ? I have not removed a K fuel pump before....and am not sure if this is normal.... Can anyone suggest how to get the pump out ?
David56 is offline  
Sponsored Links
post #2 of 5 (permalink) Old Aug 16th, 2011, 5:18 pm
Beemer01's Avatar
Join Date: Sep 2006
Location: Lake Forest, Il, USA
Posts: 350
Hi -

The fuel pump on an 85 is 'held' in place by a rubber fuel damper. At least on my 85 that damper has dissolved into gooey tar and broken bits.

Thats with American fuel and a bike that had sat in a garage for a decade.

You've got a problem with a jammed fuel pump from the sound of it. Take your hand and wiggle it out - expect that damper to fall apart. Remove the tank, drain everything out of it and after it dries out use compressed air to blow the crap out.

Fuel pump - assuming there is zero gasoline on this - try reversing the polarity on the terminals with 12 volts and see if that frees up the stuck impeller.

If that works, you'll need a new damper and initial screen, new in tank fuel lines and a new filter. If that does not work you'll need a new fuel pump as well.

Sorry Mate - but this is a fairly standard procedure in bringing a brick back to life.

"What follows is based on actual occurrences. Although much has been changed for rhetorical purposes, it must be regarded in its essence as fact. However, it should in no way be associated with that great body of factual information relating to orthodox Zen Buddhist practice. It's not very factual on motorcycles, either."

Robert Persig - Zen and the Art of Motorcycle Maintenance

1985 K100RS (Sold)
2000 323i (Sold)
2003 1150GS (Sold)
2009 528Xi
2004 K1200GT
Beemer01 is offline  
post #3 of 5 (permalink) Old Aug 18th, 2011, 8:10 pm Thread Starter
Join Date: Aug 2011
Location: Adelaide, S.A., Australia
Posts: 4
Angry Stuck Fuel Pump

Thanks for the comments Beemer01.
Oh this pump is not going anywhere soon !
It is not possible to move it really.
As for the pump suspension ? it appears to be in rude good health. Sitting in water for years must be good for them.

So I have all the nuts off, fuel line removed, power cables undone...but the plastic retaining ring is not coming off. It is still down hard. Force doesn't seem to do much apart from removing the ends of my fingernails.

What is supposed to happen ?

It's like the whole unit has been bonded in...

Any suggestions ?

Last edited by David56; Aug 18th, 2011 at 11:00 pm.
David56 is offline  
Sponsored Links
post #4 of 5 (permalink) Old Feb 23rd, 2012, 3:28 am Thread Starter
Join Date: Aug 2011
Location: Adelaide, S.A., Australia
Posts: 4
Look !

it's six months later and fuel pump is still stuck
David56 is offline  
post #5 of 5 (permalink) Old Feb 23rd, 2012, 7:11 am
Senior Member
Join Date: May 2011
Location: Fredrikstad, , Norway
Posts: 181
It`s a retaining lug 180 degree apart on plastic ring, which must be pressed towards centre.
Take care, these lugs easily breaks due to age.
Have a look at the pictures in this link.

Inge K.
IngeK is offline  

Quick Reply

Register Now

In order to be able to post messages on the K-Bikes.com - Excellence in Motion forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Similar Threads
Thread Thread Starter Forum Replies Last Post
K1 fuel pump malfunction choptankman Technical, Repair and Maintenance 9 Jun 22nd, 2015 12:46 pm
Interesting read on returnless type fuel systems JCW K12/1300R/R-Sport 2 May 17th, 2011 2:19 am
K75S Fuel Pump Issue cmonroe11 Other K-Bikes Discussion 16 Sep 12th, 2008 6:22 pm
K75 fuel pump fuse blowing... dlloyd Other K-Bikes Discussion 1 Sep 5th, 2006 7:14 pm
1991 K100RS Fuel Pump oilhead110 Other K-Bikes Discussion 1 Apr 14th, 2006 4:58 pm

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome