K1 - Pump not priming

[effjay]

Hi everyone,

this topic has been addressed here several times. To the best of my knowledge I have gone through many of the suggestions. I find myself however, at a dead end of my knowledge and that's why I ask for your support and guidance.

My K1 has always started. Always garaged. It has 43000 km. After this winters pause it needed a new battery (although it spent all winter on a BMW trickle charger!).

I installed a new battery and the bike started immediately. I then rode a little bit until she was warm and put her back in the garage.

A week later I turned the key and the pump doesn't prime.

Up until now I have done these things...

This is how I have tried to start the bike:
- Gear in neutral (light on dash is green)
- Killswitch on handlebars is in correct position.
- Clutch pulled.
- Side stand up.
- Fuel gauge is working.
- The starter motor spins.
- The battery is healthy.
- The fuel pump just doesn't excite.

This is what I have checked to try and rectify the problem:

- Checked all fuses for continuity - all OK.
- Each of the fuses have 12v coming in.
- Bridged the side stand switch/connector to see if the fuel pump will excite. No.
- Sprayed the side stand switch and cable connector with contact spray.
- Tested Motronic Relay - OK
- Tested fuel pump relay - OK
- Tested Motronic & fuel pump relay seat (pole 30) for 12v - OK
- Maybe there's a Motronic (engine control unit) error?
(I have unplugged it and plugged it in again more than once).

I'm stuck and would love to hear you opinions about the next steps I should be taking.

Many thanks to you all in advance!

[The Mighty Gryphon]

Is there 12 volts at the fuel tank connector when the key is turned on?  You should see 12 volts for a second or two when the key is turned.  Depending on whether or not you see that voltage will tell you where to look for a problem.

[effjay]

***UPDATE***

Removed and tested the fuel pump.
Does it work? Of course it doesn't.

Measured voltage on pump wiring - 12v delivered.

New parts on the way - actually good that we looked, the fuel pump damper was falling apart - one big sticky mess.

will report back when the parts have been installed - hopefully with good news!

[effjay]

Is there 12 volts at the fuel tank connector when the key is turned on?  You should see 12 volts for a second or two when the key is turned.  Depending on whether or not you see that voltage will tell you where to look for a problem.

Yes. 12v available at the fuel pump. 👍🏻
My update reports on the latest discoveries.