[Hardknight]

Hi Everyone,
1st time posting
Had not ridden for a 6 months or so, but use to start it every 3 or 4 weeks just make sure battery would stay good.
This did not work as the battery went flat, which I replaced and expected the bike to fire up as it normally would.
It cranks but but will not fire up.
I have checked the following.

1. There is spark and the plugs are good
2. Compression is ok
3. Cleaned the injectors
4. Tried throttle reset
5. All relay's under the seat seem to energise and engage.

Another issue is the front brake locking on and not releasing (Takes about 5 minutes or release)
After a brake flush its good for 3 or 4 months and starts again (Not sure if this should be in another post)

Any assistance would be appreciated

 

[Capt howdy]

Unfortunately starting the bike up will over time drain the battery. You need to do around 20-25 km each time you start the bike to replenish the charge from just starting it. It sounds as though your calipers could need a thorough clean. It’s possible that the pistons are gunked up/corroded. Not sure why it won’t start.

 

[RAC]

1). Make sure both battery grounds are connected. There are 2, wouldn't be first person who only hooked up one.
2). When you initially turn the key on (handlebar kill in run position) does the fuel pump cycle (run for a moment)?
3). Sure there's fuel in the tank? Don't rely on the gauge.

 

[RAC]

Calipers locking up and not releasing (any vehicle) is most often a symptom of a bad rubber brake line. Occasionally a piston stuck, but most often a brake line.

 

[Hardknight]

1). Make sure both battery grounds are connected. There are 2, wouldn't be first person who only hooked up one.
2). When you initially turn the key on (handlebar kill in run position) does the fuel pump cycle (run for a moment)?
3). Sure there's fuel in the tank? Don't rely on the gauge.

Hi RAC
I can hear the fuel pump cycle when I turn on the ignition, yes fuel in the tank , but its possibly 6 months old.
Will drain and try fresh fuel this weekend.

 

[Hardknight]

Unfortunately starting the bike up will over time drain the battery. You need to do around 20-25 km each time you start the bike to replenish the charge from just starting it. It sounds as though your calipers could need a thorough clean. It’s possible that the pistons are gunked up/corroded. Not sure why it won’t start.

The brakes are 3K old not much wear as I generally use the rear brake.
I have heard of a relief valve that sticks or clogs, although on opening the reservoir iseems to be clear and clean

 

[H96669]

That the fuel pump cycle (prime) when turning the ignition On does not mean that it runs when cranking.Prime cycle is pump powered via the ECU/ECU (Motronic) relay. Run cycle is Hall sensor signal-ECU-Fuel pump relay.

 

[Beech]

It is generally the inside lining of the brake line comes loose and acts as a flapper check valve. Rubber brake lines are done after 8 years or so, after that it is a wish and a prayer.

 

[Hardknight]

That the fuel pump cycle (prime) when turning the ignition On does not mean that it runs when cranking.Prime cycle is pump powered via the ECU/ECU (Motronic) relay. Run cycle is Hall sensor signal-ECU-Fuel pump relay.

Hi H96669
I am aware that it primes (3- 5 secs) and does not continue during cranking, can you check if its actually pumping and not just making the priming sound ?

 

[Hardknight]

It is generally the inside lining of the brake line comes loose and acts as a flapper check valve. Rubber brake lines are done after 8 years or so, after that it is a wish and a prayer.

Hi Beech, so the problem could not be the master cylinder ?

 

[Lowndesw]

Hardknight,

I have a '00 K1200RS and a '99 R1100S, very similar brake and fueling systems, mechanically. I've had both problems on one or the other, or both bikes.

Front brake locking - Do you have the OEM (black rubber lines) on the bike?? If so they are way overdue. Galfer or Speigler braided SS PTFE lines for the clutch, front and rear brakes, COMPLETE. AMHIK. It's not the miles it's the years soaking in DOT4 that destroys the OEM lines. Story and pics here: https://www.bmwsporttouring.com/messenger/104113/ Chunks of the decomposing brake line settle into the caliper and make a check valve (see pics) that let pressureand DOT4 into the pistons but not out. THAT is what the problem is. To clear it you have to separate the caliper halves and remove the chunks. Blowing air thru the caliper galleries won't clear it. AMHIK.

Not cranking - Its either spark or fuel. You have spark so check the fuel delivery. You can check the return flow on the fuel lines (from the tank to the fuel rail). If you still have the black plastic fuel line disconnects on the bike you need to replace those with plated brass disconnects: New CPC Chrome Plated Brass Fuel Line Quick Disconnect Set - Oilheads & K-Bikes
The plastic connects are a known problem, cracking and leaking. Save the plastic units to plug into the brass units (after they are installed) to check the flow and return flow. The disconnects have to be mated to flow. They have built in check valve/backflow preventers on both sides. When you are connecting and deconnecting the plastic AND brass connectors push the release button while inserting. Otherwise the "catch" will nick the tiny O-ring and it will not seal and will leak. The brass units come with an extra set of O-rings just for this.

A good return flow (strong flow about the size of a pencil) tells you 1) the pump is pumping and the power is good, 2) the hoses in the tank are OK, not split and leaking, 3) the return line and pressure releif valve are good. If you can hear the pump run and no flow, then you are 95% sure the problem is in the lines in the tank, cracked, split, or disconnected lines. Anything less than strong flow about the size of a pencil indicates it's time for a pressure test on the pump.

A pressure test can be done with the the extra fuel line connector and without removing the tank or pump. Put a 12-18 inch length of fuel tubing on the extra fuel connector (fuel pump side) and a 0-100psi gauge clamped on the other end. Connect this to the fuel lines coming from the TANK. Then turn the ignition key ON but do not crank. The pump should run for about 2 seconds, enough to read the pressure. Less than 45-50 psi means the pump is bad and/or a fuel line is cracked or split and leaking inside the tank.

The return flow test can be done in a similar way by using the extra connector with 12-18 inches of fuel line connected to the return line from the engine.

It's time for those lines to be replaced anyway. Fuel system components for BMW K100
Ethanol gasoline degrades the rubber lines over time and they crack or split.

Use the Oetiker type SS fuel line clamps everywhere. The screw-type fail. It's waaay too much trouble to try to fix this on the side of the road somewhere. AMHIK.
https://www.amazon.com/Stainless-6-23-5mm-Assortment-Automotive-Appliance/dp/B0B2R3WZ9C/ref=sr_1_1_sspa?crid=2FCN5C2T8Y52M&keywords=oetiker+clamp+kit&qid=1678413983&sprefix=Oetiker,aps,101&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzUDFYUktaODhYVEtZJmVuY3J5cHRlZElkPUEwOTI1OTI2WVQ1NE1KTUlPVjE1JmVuY3J5cHRlZEFkSWQ9QTAzMjcwNDJQSEdQUzM5R1VEVDAmd2lkZ2V0TmFtZT1zcF9hdGYmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl

 

[Beech]

Yes, it is very unlikely that it is anything other than the front rubber brake lines. Meaning you need to change all of them on the bike. Spiegler has kits for teflon lined brake lines.

 

[H96669]

Hi H96669
I am aware that it primes (3- 5 secs) and does not continue during cranking, can you check if its actually pumping and not just making the priming sound ?

First of all and F.I. 101 check fuel pressure.That's the first thing to do on any FI engine.52Psi on prime and if pump is running well pressure will remain constant when cranking.

DIY fuel injectors cleaning or a pro job with a balance,spray pattern,flow test etc.... report?

 

[Hardknight]

Hardknight,

I have a '00 K1200RS and a '99 R1100S, very similar brake and fueling systems, mechanically. I've had both problems on one or the other, or both bikes.

Front brake locking - Do you have the OEM (black rubber lines) on the bike?? If so they are way overdue. Galfer or Speigler braided SS PTFE lines for the clutch, front and rear brakes, COMPLETE. AMHIK. It's not the miles it's the years soaking in DOT4 that destroys the OEM lines. Story and pics here: https://www.bmwsporttouring.com/messenger/104113/ Chunks of the decomposing brake line settle into the caliper and make a check valve (see pics) that let pressureand DOT4 into the pistons but not out. THAT is what the problem is. To clear it you have to separate the caliper halves and remove the chunks. Blowing air thru the caliper galleries won't clear it. AMHIK.

Not cranking - Its either spark or fuel. You have spark so check the fuel delivery. You can check the return flow on the fuel lines (from the tank to the fuel rail). If you still have the black plastic fuel line disconnects on the bike you need to replace those with plated brass disconnects: New CPC Chrome Plated Brass noFuel Line Quick Disconnect Set - Oilheads & K-Bikes
The plastic connects are a known problem, cracking and leaking. Save the plastic units to plug into the brass units (after they are installed) to check the flow and return flow. The disconnects have to be mated to flow. They have built in check valve/backflow preventers on both sides. When you are connecting and deconnecting the plastic AND brass connectors push the release button while inserting. Otherwise the "catch" will nick the tiny O-ring and it will not seal and will leak. The brass units come with an extra set of O-rings just for this.

A good return flow (strong flow about the size of a pencil) tells you 1) the pump is pumping and the power is good, 2) the hoses in the tank are OK, not split and leaking, 3) the return line and pressure releif valve are good. If you can hear the pump run and no flow, then you are 95% sure the problem is in the lines in the tank, cracked, split, or disconnected lines. Anything less than strong flow about the size of a pencil indicates it's time for a pressure test on the pump.

A pressure test can be done with the the extra fuel line connector and without removing the tank or pump. Put a 12-18 inch length of fuel tubing on the extra fuel connector (fuel pump side) and a 0-100psi gauge clamped on the other end. Connect this to the fuel lines coming from the TANK. Then turn the ignition key ON but do not crank. The pump should run for about 2 seconds, enough to read the pressure. Less than 45-50 psi means the pump is bad and/or a fuel line is cracked or split and leaking inside the tank.

The return flow test can be done in a similar way by using the extra connector with 12-18 inches of fuel line connected to the return line from the engine.

It's time for those lines to be replaced anyway. Fuel system components for BMW K100
Ethanol gasoline degrades the rubber lines over time and they crack or split.

Use the Oetiker type SS fuel line clamps everywhere. The screw-type fail. It's waaay too much trouble to try to fix this on the side of the road somewhere. AMHIK.
https://www.amazon.com/Stainless-6-23-5mm-Assortment-Automotive-Appliance/dp/B0B2R3WZ9C/ref=sr_1_1_sspa?crid=2FCN5C2T8Y52M&keywords=oetiker+clamp+kit&qid=1678413983&sprefix=Oetiker,aps,101&sr=8-1-spons&psc=1&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEzUDFYUktaODhYVEtZJmVuY3J5cHRlZElkPUEwOTI1OTI2WVQ1NE1KTUlPVjE1JmVuY3J5cHRlZEFkSWQ9QTAzMjcwNDJQSEdQUzM5R1VEVDAmd2lkZ2V0TmFtZT1zcF9hdGYmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl

 

[Hardknight]

Hi Lowndesw.
Delving deeper I opened the tank and discovered, that do not always believe you mechanic 🤬 that they changed the fuel filter. and checking the fuel pump in my
hand that it had no flow .
Just ordered a replacement and waiting for delivery from the US.

 

[Hardknight]

Hi Lowndesw.
Delving deeper I opened the tank and discovered, that do not always believe you mechanic 🤬 that they changed the fuel filter. and checking the fuel pump in my
hand that it had no flow .
Just ordered a replacement and waiting for delivery from the US.

 

[Beech]

Sad you can't trust your mechanic. Euromotoelectric has all the parts you need. I'd change the hoses to. Use crimp Otekier fittings if at all possible. And clean the contact area of the electrical connections. Test your pump before you put it back, don't run it longer and a second or two dry.

 

[Hardknight]

Thanks Beech,
Testing the pump will be done submerged, hopefully the new pump will bring the bike back to life.
Don't need another thing to add to the list, as a bike of this age it will start to become economical to keep her running
Some pics below of the hardware when removing the tank.

A little bit cleaner

 

[Beech]

Your lucky the wiring is still okay. Be careful testing the pump. Personally I would only test it in the tank sealed. If bench testing (much easier) only spin it for a few seconds as mentioned. Open gasoline is too freaky.

 

[RAC]

Just use a little kerosene or diesel for bench testing. Far less volatile and leftovers of both will mix readily with fuel in the tank after installation (drain out as much as possible prior to install and cycle pump several times prior to first start to make sure you have "gas" in the system).
Wear appropriate PPE in case of a leak. Don't want any high pressure spray of any of the 3 getting you in an eye or something.