Author Topic: blocked filter screen  (Read 1893 times)

Offline Robzki

  • Motobrick Curious
  • Posts: 14
blocked filter screen
« on: September 15, 2017, 07:40:12 PM »
Hi all

After typing  a really nice, polite and sensible first message on the site, it was deleted because the pic was too big..........

That's an hour I'll never get back.

k1100lt, '97, grey, 87k miles new to me

Noisy fuel pump after 5 mins riding, no different full or empty, fuel tank immaculate, blowing through filter is easy and seems like new, pump rubbers etc feel supple and like new.

Screen/sock looks manky. shining a bright led torch through lets no light through

Could the sock be causing enough of a restriction to make the pump noisy after a few minutes(kinda vacuum?) when the bike is switched off the vacuum pulls fuel into the sock which explains the quiet operation for a few mins?

just conjecture, I don't mind buying a pump etc but the bike is in such a mess that I have many many other ways to 'invest it' oh, that and the fact I am pretty sure I have lost most of my life stability and plan on having a midlife crisis later in a  week or so. Would be nice if the K could join me on the adventure.

Thanks and I have searched but haven't found any posts similar.

Thanks in advance and I will post up a proper first post soon with some pics of the 'project'

Rob
  • Devon, UK
  • 1998 K1100LT

Offline Robzki

  • Motobrick Curious
  • Posts: 14
Re: blocked filter screen
« Reply #1 on: September 15, 2017, 07:46:49 PM »
Sorry, posted here in error, sums up my day...

oh and can't edit/delete? is this missing until I have had numerous posts disappear while posting as the pic is too large and posted a certain number of messages in the wrong place? :)
  • Devon, UK
  • 1998 K1100LT

Offline Laitch

  • ^ Quintessential Motobricker
  • Posts: 5208
Re: blocked filter screen
« Reply #2 on: September 15, 2017, 07:52:45 PM »
Welcome, Robski!

Replace the sock and replace the fuel filter at the same time. You've posted in the right place. You're bike will be a project to one extent or another. Might as well keep the pain all together.  :yes

Good luck with your crisis; try to avoid prison.
  • Along the Ridley in Vermont.
  • 1995 K75T 68,000 miles
I wept because I had no radials until I met a man who had no splines.

Offline Robzki

  • Motobrick Curious
  • Posts: 14
Re: blocked filter screen
« Reply #3 on: September 15, 2017, 08:09:30 PM »
Thanks Laitch :)

I was hoping to clean it if that is possible? It was getting late tonight so didn't get a chance to try. it seems I can get a new pump/screen for 40 hfp439b I think. I will give it a blow out and soak in something cleaning wise tomorrow, unfortunately I have so many other issues I'm sorting and in pieces that I wont have much of a chance to test before I go on a road trip.

I think Prison would be a bonus at the moment. Prison would mean I don't have a housing problem, and I may even manage to sort a new relationship, everyone loves a pretty newbie.

Thanks for the Welcome, much appreciated

Rob

  • Devon, UK
  • 1998 K1100LT

Offline Laitch

  • ^ Quintessential Motobricker
  • Posts: 5208
Re: blocked filter screen
« Reply #4 on: September 15, 2017, 08:31:14 PM »
. . . everyone loves a pretty newbie.
Everybody except the jilted oldbies, whose shanks are as sharp as anybody's. :giggles
  • Along the Ridley in Vermont.
  • 1995 K75T 68,000 miles
I wept because I had no radials until I met a man who had no splines.

Offline Robzki

  • Motobrick Curious
  • Posts: 14
Re: blocked filter screen
« Reply #5 on: September 15, 2017, 09:03:20 PM »
Everybody except the jilted oldbies, whose shanks are as sharp as anybody's. :giggles

  :ba: :oldguy: :viivi
  • Devon, UK
  • 1998 K1100LT

Offline Martin

  • ^ Quintessential Motobricker
  • Posts: 3416
Re: blocked filter screen
« Reply #6 on: September 15, 2017, 09:16:09 PM »
Welcome to the asylum from the land of OZ. Try soaking in vinegar, well known solution for cleaning Brick petrol tanks, and freeing up seized fuel pumps.
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline Robzki

  • Motobrick Curious
  • Posts: 14
Re: blocked filter screen
« Reply #7 on: September 16, 2017, 04:33:46 AM »
Thanks Martin, great idea.


Not sure why I didn't think of that, must be tired and
confused. I have never soaked anything other than my chips in vinegar but after reading about the process I am soaking some exhaust parts in vinegar.


Cheers


Rob
  • Devon, UK
  • 1998 K1100LT

Offline Scott_

  • Forum Moderator
  • ^ Quintessential Motobricker
  • Posts: 1840
Re: blocked filter screen
« Reply #8 on: September 16, 2017, 10:54:21 AM »
If all of the cleaning doesn't solve (disolve...lol) anything, it could possibly be that your fuel pressure regulator could be acting up a bit.
If you have a means to measure the fuel pressure that could help determine the issue, before you buy a new pump.
  • My Garage
Ride safe.


1997 K1100LT 0302488
1995 K1100LT 0302044
Garmin StreetPilot 2820
Garmin Zumo 550
"One who does not ask questions is ashamed to learn" Danish proverb

Offline Robzki

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  • Posts: 14
Re: blocked filter screen
« Reply #9 on: September 16, 2017, 12:02:09 PM »
Thank Scott,


I will check that next. I haven't soaked in vinegar yet as have had a busy day.... This evening I am going to (safely) put the pump in a small tank of petrol and try and recreate the problem. Then I can soak overnight, run the pump in reverse to force check it is clear and then hook it up to test again.


I assume it would be OK to soak the lower part of the pump in vinegar?


If I'm not back in 24hrs then the test tank wasn't as safe as I would have hoped....


Cheers and thanks for all your advice


Rob
  • Devon, UK
  • 1998 K1100LT

Offline Robzki

  • Motobrick Curious
  • Posts: 14
Re: blocked filter screen
« Reply #10 on: September 16, 2017, 04:10:53 PM »
quick update:


I (safely it turns out) the pump in a jar filled with fuel. left the sock and the filter attached and then had a return back into the jar.


The pump ran nicely but pumped a little air from the sock/bottom of the pump ?? it was intermittent, I rocked the jar thinking that it could just be an airlock but the air bubbles carried on. after 5 mins or so the pump noise increased and so did the bubbles out of the base of the pump/sock.


the pump continued to pump a steady stream of petrol for the whole time with no bubbles being pumped into the jar, just  a steadyish stream of tiny bubbles from the bottom of the pump/sock.


I then held my finger over the end of the pipe(under the fuel), the noise increased and the pressure was v high, would have been unable to stop the flow of fuel but it was also now pumping a lot of air, enough to make the fuel into a froth.


I'm a little confused as to where it is getting the air. The only place possible was the top of the pump as it was just above the surface, Does anyone know what the strange clip thing on top of the pump is, it looks like it is retaining a spring?


Someone here mentioned cavitation, will have a google.


The sock was pretty clear, I took it off and blew back through it and there was very little resistance.


Sorry to waffle on, I am pretty resigned to buying a new pump, just like to know why it is behaving this way. hate being confused :)


cheers


Rob
  • Devon, UK
  • 1998 K1100LT

Offline Martin

  • ^ Quintessential Motobricker
  • Posts: 3416
Re: blocked filter screen
« Reply #11 on: September 16, 2017, 04:21:37 PM »
If the pump is fully submerged once the internal air has been bled you should have no bubbles. Is the pump OEM, the original pumps had a basket but due to the baskets cost some were later fitted with socks. Pictures of your pump and the test device showing the level of fuel would help in determining the problem. You will be awarded extra Brownie points for posting piccies, inmates love piccies and sound recordings.
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline Robzki

  • Motobrick Curious
  • Posts: 14
Re: blocked filter screen
« Reply #12 on: September 16, 2017, 04:23:20 PM »
oh and just to mention that after running for 15mins in the same 1/2 litre of fuel the pump and fuel was only just a little warm, much less than I thought there should be


 Cavitation seems to make sense now as it seems to be caused(after a quick google) by either fuel boiling or if the inlet side has a resistance(the sock) .........possibly......
  • Devon, UK
  • 1998 K1100LT

Offline Robzki

  • Motobrick Curious
  • Posts: 14
Re: blocked filter screen
« Reply #13 on: September 16, 2017, 04:25:22 PM »
If the pump is fully submerged once the internal air has been bled you should have no bubbles. Is the pump OEM, the original pumps had a basket but due to the baskets cost some were later fitted with socks. Pictures of your pump and the test device showing the level of fuel would help in determining the problem. You will be awarded extra Brownie points for posting piccies, inmates love piccies and sound recordings.
Regards Martin.


Will test again in the morning and provide pics/vid :) always nice to know how to impress the other inmates  :clap: :yes
  • Devon, UK
  • 1998 K1100LT

Offline BrickMW

  • ^ Proficient Motobricker
  • Posts: 126
Re: blocked filter screen
« Reply #14 on: September 17, 2017, 10:15:27 AM »
Perhaps try a run without the sock, since debris in your test rig should be easily eliminated and really of little concern with the absence of fuel injectors downstream.

The pump's internal pressure bypass exits from the bottom of the pump, inside the sock or screen cup. Basically a ball check valve allowing excess pressure to dump back to the tank. An "unrestricted" and unregulated test rig should be passing all pressure through the output of the pump and none from the internal bypass.

More details needed about the clip you mentioned.

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  • Huntsville, AL
  • 1986 K75c
Luft & Jager... My two favorite Meister's :bmwsmile

Offline Robzki

  • Motobrick Curious
  • Posts: 14
Re: blocked filter screen
« Reply #15 on: September 23, 2017, 03:01:08 AM »

Apologies for the very late reply, had a meltdown and decided to go for a drive for a few days....


Well I tested the pump a few more times before finally giving up and ordering a new one. I like to save as much money as possible wherever possible but not to the detriment of reliability or general servicing. I knew it was inevitable but will always try to exhaust all possible ways before punishing the credit card.


The tests were ended early when I ripped the sock removing it, I think I ripped it subconsciously because I did really want a shiny new pump  :yes


I have attached a youtube....possibly. I used to be a computer geek but gave that up years ago and have never really bothered myself with adding pics/vid to forum posts....must try harder.


The vid doesn't really show how much air was being drawn but it does cover possiblly an hr of the pump running. the sound didn't get as loud as it was in the tank but I really didn't want to get stuck in the middle of nowhere or risk the pump flowing fuel and air and causing the bike to run lean. I may even add an AFR gauge at a later date just to give me something else to worry about  :nono






A new sock was 20-30 a new pump/sock was 40 it arrived within 24hrs and looks good but will post a review later.... while the Credit card was out I ordered a complete service kit and a few other bits and pieces.


Thank you again for all of the advice and help, it is very much appreciated and shows what a great community you have here.


Cheers


Rob

  • Devon, UK
  • 1998 K1100LT

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