2004 R1150R sudden loss of power

[Universal_mind]

2004 BMW R1150R 44,000mi
 

So I pull my bike out this spring, and it starts and runs just fine. On my second ride I’m cruising down the road at speed and suddenly all engine power is lost. Any throttle above idle causes the engine to sputter and die. Bike will

start and idle again immediately. 
 

Full disclosure: I’ve had this problem before. In the recent past I have changed the fuel pickup strainer and pump, but that didn’t fix it. I replaced the battery, and that DID seem to fix it (until now). The new battery was on a tender for several months, so I checked voltage which seems all good.  
 

Please HELP!

[dirtrider]

49 minutes ago, Universal_mind said:

2004 BMW R1150R 44,000mi
 

So I pull my bike out this spring, and it starts and runs just fine. On my second ride I’m cruising down the road at speed and suddenly all engine power is lost. Any throttle above idle causes the engine to sputter and die. Bike will

start and idle again immediately. 
 

Full disclosure: I’ve had this problem before. In the recent past I have changed the fuel pickup strainer and pump, but that didn’t fix it. I replaced the battery, and that DID seem to fix it (until now). The new battery was on a tender for several months, so I checked voltage which seems all good.  
 

Please HELP!

 

Morning  Universal_mind

 

It sort-of is pointing to a fuel flow problem but a spark issue can act very similar at times. 

 

You might have a split "U" shaped high pressure hose inside the fuel tank as that can act like what you are seeing with the idle OK but no power at higher throttle openings. 

 

Otherwise it could be anything from a plugging fuel filter, to an HES signal issue, to an engine sensor issue, to ???

 

Probably the place to start your diagnostics is to do a fuel return flow test as that will tell you if you have enough fuel flowing at enough pressure to run the engine under load at speed. (at least that will OK your fuel supply system as the possible cause then if OK you can move on to testing other things). 

 

Basically the BMW fuel injected 1150 boxer bikes have a built in fuel pressure tester--

 

 Your bike has an inline fuel pressure regulator that maintains fuel pressure in the fuel manifolds. What that fuel pressure regulator does is FORCE the fuel pump to reach about 50+psi before it will allow by-pass fuel to flow back through the return line back into the fuel tank.

 

 If your fuel pump is bad (low pressure output), or a split internal hose, or plugged filter then it can't reach the required 50+psi so the pressure regulator won't open so you will then have NO return fuel flowing back to the fuel tank.

 

 Or--IF your high pressure fuel lines are leaking inside the fuel tank it can't reach the required 50+psi so the pressure regulator won't open & again you will have NO return fuel flowing.

 

 Or-- IF your fuel pump can't pump enough fuel quantity (low output), like restricted filter, or split in-tank fuel line)  it can't reach the required 50+psi so the pressure regulator won't open & you will again  have NO return fuel flowing.

 

 On the other hand (IF) you have  the engine running with a decent amount of fuel flowing back through the return fuel line that means that--- "your pump can meet or exceed the 50+psi system supply requirement" (PLUS) supply it at a flow rate above the amount required to run the engine at idle. (actually a better test than simply using a fuel pressure gauge)

 

With the engine  idling & NO fuel flowing back through the return line that tells you that -- Either the pump can't produce the required 50+psi, or the pump can't produce the required fuel flow (at enough pressure)  to run the engine, plus supply extra fuel flow to run the engine at higher load.

 

With the engine  idling & (just a little) fuel flowing back through the return line that tells you that --The pump can produce the required 50+psi BUT the pump can't produce the required fuel flow at that required  50+ psi to run the engine, plus supply extra fuel flow to run the engine at higher load. (will idle OK but not pull at higher engine loads)

 

With the engine  idling & a good amount of fuel flowing back through the return line that tells you that --The pump CAN produce the required 50+psi, AND the pump CAN produce the required fuel flow to run the engine, plus supply the extra fuel flow to run the engine at higher load at higher speeds.

  

 

 

[Jim Moore]

That sound like  a hose blown off in the tank, or a split line.

[Universal_mind]

I’m going to test the fuels system today, but I thought this would be good info to add:

 

When I got the bike home, I fired it up to test the battery voltage & alternator. She fired right up and revved like normal.  In addition,  I changed the fuel pump and inspected the U shaped high pressure hose less than 200 miles ago.
 

This makes me think it is not a fuel system problem. 

 

Does anyone know if there are common electrical problems that could result in the behavior I’ve described?  If so, are there any diagnostic tests I can run on my own? 
 

Thank you all for your advice!

[dirtrider]

21 minutes ago, Universal_mind said:

I’m going to test the fuels system today, but I thought this would be good info to add:

 

When I got the bike home, I fired it up to test the battery voltage & alternator. She fired right up and revved like normal.  In addition,  I changed the fuel pump and inspected the U shaped high pressure hose less than 200 miles ago.
 

This makes me think it is not a fuel system problem. 

 

Does anyone know if there are common electrical problems that could result in the behavior I’ve described?  If so, are there any diagnostic tests I can run on my own? 
 

Thank you all for your advice!

 

Morning  Universal_mind

 

On the engine starting & revving when you got it home-- Sometimes they will run out OK cold as the tank internal hose is cold &  stiff, once the fuel in the tank warms up (from hot return fuel) the hoses will soften & leak more. 

 

On the electrical side, that is a going to be somewhat of an issue to test as the engine runs at idle even with the problem present. So that sort of eliminates an open circuit or a short circuit.

 

Your 2004 1150 has basically 2 ignitions (upper spark plugs on stick coils & lower spark plugs on a conventual coil. The common tie together is at the HES. The 2004 1150RT's have very few HES problems & when they do it usually results in a total engine quit.  

 

Back to your fuel side--definitely do the fuel flow test as that will basically eliminate that (if done with hot or warm fuel in the tank).

 

Have you ever heard a suction sound, or wooosh sound, or difficult to open cap  when you open the fuel filler cap after riding the motorcycle for a while or for longer miles? If so let us know as that might lead to another test. 

 

Added: What type of hose clamps did you use when you-- changed the fuel pump and inspected the U shaped high pressure hose less than 200 miles ago ? If you used cheap worm drive type standard low pressure hose clamps those tend to eat into the hose then start leaking after a while when used on high pressure in-tank fuel systems.  

 

 

 

 

[Universal_mind]

Well, I tested the fuel system (while cold) and got fuel flow from the return line as expected. So I put it back together, and I rode around to get the fuel warm. It didn’t take long for the problem to return... just as though it was running out of gas...

Didn’t have time to take it all back apart to test fuel flow while hot, but I’m convinced.
 

My next move was to order replacement in-tank fuel line & filter replacement kits from BeemerBoneyard.  I’ll be updating the thread once they’re replaced. 
 

 

additional notes:

I used crap worm drive hose clamps previously. 
There does not seem to be vacuum forming in the tank. I checked for that before replacing the fuel filter & pump as well. 

[Universal_mind]

Parts were delivered today, so I got the internal high pressure fuel lines changed.

 

After I put the bike back together it seemed to start & run smoother than before.
 

Unfortunately, after I rode about 10 miles down the road I felt a similar loss of power as before. Everything seemed to go back together very well.   Soooo I’m lost... again... 🤪

 

 

[dirtrider]

1 minute ago, Universal_mind said:

Parts were delivered today, so I got the internal high pressure fuel lines changed.

 

After I put the bike back together it seemed to start & run smoother than before.
 

Unfortunately, after I rode about 10 miles down the road I felt a similar loss of power as before. Everything seemed to go back together very well.   Soooo I’m lost... again... 🤪

 

 

 

Evening  Universal_mind

 

If you are positive that your fuel system is performing properly then you are going to have a difficult time pinning this one down. 

 

Something is shutting partially  down so if it isn't fuel delivery then it is either spark, or air delivery, or exhaust, or fuel injection control.

 

If it would just totally quit then it would a lot easier to find.

 

Could be the HES acting up but that usually just quits, not partially shuts down (but sure is possible)

 

Could be the Motronic acting up (this one it REALLY difficult to pin down without having a known good Motronic to install for a test). 

 

Could be an engine sensor (like the TPS) this it testable but it won't show you anything unless it is actively acting up during the test.

 

Could even be something inside the catalytic converter or  muffler moving around & partially choking off the exhaust flow. (this you might catch by exhaust sound & you can run a pressure gauge on the o2 sensor hole in the the exhaust looking for a pressure increase as it acts up). 

 

If I could ride the motorcycle  during the time that it is acting up I can usually get an idea on what system is causing the problem (at least most times).

 

If you can give us WAY more info (every little detail) just prior to it acting up, as it acts up, & during the engine power loss  we might be able to guide you better on finding the problem. But if you miss a small detail or didn't feel something then it could also guide us in the wrong direction. 

 

I think the next move would be to unplug the o2 sensor then ride the motorcycle to see if that makes a difference. Sometimes an o2 sensor acting up can cause unique runability problems.    

 

 

 

 

[Universal_mind]

Took the tank apart a second time to make sure I didn’t have a kinked hose or something stupid going on. 
 

Problem remains the same.
 

I made a video of the bike running...

 

Do I have to take the tank off again to unplug the O2 sensor?

[dirtrider]

2 minutes ago, Universal_mind said:

Took the tank apart a second time to make sure I didn’t have a kinked hose or something stupid going on. 
 

Problem remains the same.
 

I made a video of the bike running...

 

Do I have to take the tank off again to unplug the O2 sensor?

 

Afternoon Universal_mind

 

Sounds like it's running out of fuel as you aggressively revv it. If you are getting plenty of fuel out of the return hose then possibly is a fuel command issue, like TPS signal or ??????

 

You might check the TPS low & high outputs to see if they scroll evenly from idle to 1/2 throttle then check the high output from idle to wide open throttle.

 

At slow revving it seems to get to higher RPM's  so at a slow revv it might be fueling from the o2 sensor so it doesn't need the other sensors for no-load fueling control. 

 

Nothing in the air box, or in the  snorkel, or  in the air filter getting sucked in to block the intake air is there?

 

You might have to lift the rear of the fuel tank up to access the o2 sensor connector, depends on where it was placed last time it was accessed. 

[Jim Moore]

Man, that's weird. I gotta say, I would expect fuel starvation to be a little jerkier than that. That looks more like the engine is just shutting down. Something electrical, but I can't imagine what.

[Universal_mind]

It seems to run the same with the o2 sensor detached.
 

Can you help me with the TPS sensor test procedure?

[dirtrider]

4 minutes ago, Universal_mind said:

It seems to run the same with the o2 sensor detached.
 

Can you help me with the TPS sensor test procedure?

 

 

Evening Universal_mind

 

Can you revv it the same to a higher RPM with the o2 disconnected? (might tell us something).

 

Check your messages on this site as I just sent you a TPS test procedure. 

[Lowndes]

Ignition switch??

[dirtrider]

9 minutes ago, Lowndes said:

Ignition switch??

Morning  Lowndes

 

It still idles OK & tachometer seems to be working & tracking, plus engine picks right back up as he backs off the twist grip  so ignition switch seems unlikely.

[Beamer boy]

Hi Sounds like loss of compression.

Leaky (burned valves) or valves too tight.

or steatched tap ends.

 

One of the reasons the valves can be too tight is that the Rocker arm has play and it sits in two positions.

 

A compression test will not always reveal this problem. 
 

caution do not tighten the tap ends just het you might pull them out of the block.

The Beamer alu is very sensitive.

 

Burned valves are known for bad idle and loss of power.

 

But before you go nuts and pull it all apart just check if these fast disconnects in the fuel lines are fully in place (“click”?).

The issue could also be electrical. First suspect is the kill switch. 
When you rev up the engine put your hand on the fuel and Motronic relay and check if you feel them switching.

You could also bridge out the kill switch temporarily to rule out this thing.

Or put in some tiny wires with the relay in the socket and measure with a multi meter in your tank bag while you do a test run. 

 

Drive safe keep your eyes on the road!

 

We love to hear from you.

 

Beamer Boy 

[dirtrider]

3 hours ago, Beamer boy said:

Hi Sounds like loss of compression.

Leaky (burned valves) or valves too tight.

or steatched tap ends.

 

One of the reasons the valves can be too tight is that the Rocker arm has play and it sits in two positions.

 

A compression test will not always reveal this problem. 
 

caution do not tighten the tap ends just het you might pull them out of the block.

The Beamer alu is very sensitive.

 

Burned valves are known for bad idle and loss of power.

 

But before you go nuts and pull it all apart just check if these fast disconnects in the fuel lines are fully in place (“click”?).

The issue could also be electrical. First suspect is the kill switch. 
When you rev up the engine put your hand on the fuel and Motronic relay and check if you feel them switching.

You could also bridge out the kill switch temporarily to rule out this thing.

Or put in some tiny wires with the relay in the socket and measure with a multi meter in your tank bag while you do a test run. 

 

Drive safe keep your eyes on the road!

 

We love to hear from you.

 

Beamer Boy 

Afternoon  Beamer Boy

 

Well, it has an almost perfect idle so that pretty well says the valves are OK.

 

Tachometer is still functioning so that pretty well rules out both the kill switch &   Motronic relay. 

 

 

[Mrclubike]

I wonder if he has 2 bad stick coils and now his secondary 2 tower coil is failing causing the lose  of power 

I know for a fact the dual plug oil heads will run ok with bad stick coils

Mine did except for the slow speed surging

Very  easy to test the spark

 

[Beamer boy]

“

Spoiler

 

Well, it has an almost perfect idle so that pretty well says the valves are OK.

 

Tachometer is still functioning so that pretty well rules out both the kill switch &   Motronic relay.”

 

 

Hi dirt rider,

 

Have you tried to use the kill switch and see if this has the same effect on the Tachometer as the problem does? I wonder if it does.

Try to wiggle 50 times with the kill switch it gets rarely used and after 15 years the corrosion (=resistance) builds up. 

Check if the switches on the right handle bar are clean. Lubricant from the throttle cable and brake oil are close to this switch. Rain and little or no use of the switch make it worse. It does not have to be the issue but electrical faults are difficult to diagnose and you certainly don’t want to be shotgunning new parts on the bike finding later out that it is some simple electrical issue like this one for example. 
 

Intake valves: 
 

if the intake valves are too tight you should see a bit of contamination in your throttle bodies.
(when the bike is heating up blow back of exhaust gases in the intake. Killing the power when the bike sucks in new combination gases (because it only sucks in the fumes).

 

Evidence of this happening:

 

The throttle body should be clean nice and shiny. Brown tarnish or brownish glow indicates issues.

It you clean them and it comes back, than you have leakage on the intake.

 

BMW has chosen 30 degrees angle on the intake valves which is good for cooling the valves (needed with lean and hot running air cooled engines) but unfortunately less effective closing the valve seat. (Water cooled engines used topically 45 degrees angle on the valves)

 

Other errors which can contribute to the valve issue are the rockers.

 

The rockers wear in and can sit in 2 ways over the shaft because the play they have over the rocker shaft, that can cause the intake to leak. And if that happeneds the fuel will not enter the combustion chamber and the power is lost. 
 

The cylinder cools down and the play is gone and the bike goes again.  Some bikes have this at high speed where they loose power and they pick up again and heat up and loose power again. 

Mmmm 

 

My best bed is still: the valves. 
A test setting the intake a little wider doesn’t take up a lot of time. 
 

Toggling 50x the kill switch or bridging it out for a test will also not be a big hassle.

(the kill switch turns off the Motronic and the fuelpump). 

 

The fuelpump: The electrical connector under the tank also feeds the fuelpump. The brown wire is the minus (gnd) of the battery. The other green wire also thicker on the side of the tank is the +12V to the fuelpump. If the voltage drops there then there is an issue you need to sort out. 
 

Anyway do a few more test you are getting close to fix the issue.

 

Electrical issue ? Grease or corrosion on handle bar switch should be easy to find.

 

Mechanical ? Dirty TB and intake play intake valves is also something which can be diagnosed quite simple.

 

Beamer boy 

edited 2 hours after initial post! 
 

 

Edited May 24, 2020 by Beamer boy
Language edit

[Beamer boy]

Good morning/ good evening Dirt Rider,
 

I have one more test for you beside the things I asked you to check in the previous post.

 

Test 1/  take the electrical connector lose to the injector of the left cylinder. And check the RPM. Reconnect the connector.

 

Test 2/  take the electrical connector lose to the injector of the left cylinder. And check the RPM. Reconnect the connector.

 

both RPM’s should be the same. 
The engine would be struggling to keep running in both cases. But different RPM’s indicate which cilinder is not working as well as it could.

 

The list of errors could be:

Fuel mixture, 

injector needs ultrasonic cleaning 

Valves need adjusting (in particular intake)

 

Can you still rev up the engine and see if it kills also just like previously? What’s the difference? 

My thoughts are:

 

If the issue is electrical than it would still cut out the same. (The current is not affected) it it is a coil stick than wow this test would point to the weak cilinder? Don’t you think so? 

 

If the issue is mechanical electrical than it reacts differently I suppose? Not sure.

 

All the tests and inspections should hopefully get us closer to the finding the $%*¥ issue.

 

BB 

 

 

 

 

[dirtrider]

2 hours ago, Beamer boy said:

Good morning/ good evening Dirt Rider,
 

I have one more test for you beside the things I asked you to check in the previous post.

 

Test 1/  take the electrical connector lose to the injector of the left cylinder. And check the RPM. Reconnect the connector.

 

Test 2/  take the electrical connector lose to the injector of the left cylinder. And check the RPM. Reconnect the connector.

 

both RPM’s should be the same. 
The engine would be struggling to keep running in both cases. But different RPM’s indicate which cilinder is not working as well as it could.

 

The list of errors could be:

Fuel mixture, 

injector needs ultrasonic cleaning 

Valves need adjusting (in particular intake)

 

Can you still rev up the engine and see if it kills also just like previously? What’s the difference? 

My thoughts are:

 

If the issue is electrical than it would still cut out the same. (The current is not affected) it it is a coil stick than wow this test would point to the weak cilinder? Don’t you think so? 

 

If the issue is mechanical electrical than it reacts differently I suppose? Not sure.

 

All the tests and inspections should hopefully get us closer to the finding the $%*¥ issue.

 

BB 

 

 

 

 

 

Morning  Beamer boy

 

Just listen to the video above. It is not  a valve problem as  there is no firing on an open valve, no popping in the exhaust, no popping back through a throttle body.   It idles smoothly & starts to take the throttle with no popping or backfiring.  A leaking valve would be pretty evident at both idle & as the throttle was opened.  

 

He has run a couple of return fuel flow tests so it doesn't appear to be lack of fuel flow or fuel pressure (but he didn't run one on a hot fuel system so that is still unaccounted for).

 

Tachometer  is functioning all the way through the engine sag so the tac is staying powered up. That means the  Motronic  signal is good as well as the ignition switch & kill switch properly powering both the tac & the Motronic. 

 

Due to the nice even idle both side cylinders seem to be firing evenly (at least at idle). 

 

The OP hasn't been back in a while so he might have found the problem, the last thing I had him check was the TPS output sweeps & I haven't heard back from him since. 

 

 

[Beamer boy]

Good morning Dirt Rider,

 

Here is some extra information which will help you further. 

 

I have an 04 R1150RT twinspark with exactly the same issue. I have done everything you can imagine replacing the fuelpump, fuel filters, fuel lines, injectors even the hall sensor unit. Yes also the ignition coils (all 3) cables also.

 

The issue is still there. 
What issue? Well my bike has same

issue as yours. Running well and than loss of power, close throttle and than coming back to life. After rebuilding the fuel system I concluded its not the fuel system.

 

Any way I needed an other approach..

Ok so I changed the tactics and took a step back and now try to help you.

I saw in this forum two cases with burned valves and it looked very similar and pulled the head off. It just looked fine. It needed a clean up but that’s all. Will have a look at the valves and than close it again. 
OK a good clean of the piston removing all the carbon. The area near the second tiny spark plug is small and easily clogged. Especially the small spark plug. So either way it was a useful job. Bike had 20.000 miles (so I am told?). 
 

I am not convinced it’s not an electrical issue. I hear what you say about the backfiring and the electrical. 
But if it isn’t that what else can it be?

There is not much else I haven’t tried.

Ohh yes there is. Swapping the Motronic !!

I think your bike has the same issue as mine. I you fix yours I fix mine too (or the other way around). I have seen a few similar posts on other forums same issue and they are all a dead end road.

 

So let’s keep going and fix the bikes!
 

It certainly helps if you can bounce the ball back and forward. It’s almost if the devil answers your call. Yes this problem in the bike is a little devil. 
 

My bike looses power above 70mph which is not much on the German autobahn.

 

BB 

[dirtrider]

12 minutes ago, Beamer boy said:

Good morning Dirt Rider,

 

Here is some extra information which will help you further. 

 

I have an 04 R1150RT twinspark with exactly the same issue. I have done everything you can imagine replacing the fuelpump, fuel filters, fuel lines, injectors even the hall sensor unit. Yes also the ignition coils (all 3) cables also.

 

The issue is still there. 
What issue? Well my bike has same

issue as yours. Running well and than loss of power, close throttle and than coming back to life. After rebuilding the fuel system I concluded its not the fuel system.

 

Any way I needed an other approach..

Ok so I changed the tactics and took a step back and now try to help you.

I saw in this forum two cases with burned valves and it looked very similar and pulled the head off. It just looked fine. It needed a clean up but that’s all. Will have a look at the valves and than close it again. 
OK a good clean of the piston removing all the carbon. The area near the second tiny spark plug is small and easily clogged. Especially the small spark plug. So either way it was a useful job. Bike had 20.000 miles (so I am told?). 
 

I am not convinced it’s not an electrical issue. I hear what you say about the backfiring and the electrical. 
But if it isn’t that what else can it be?

There is not much else I haven’t tried.

Ohh yes there is. Swapping the Motronic !!

I think your bike has the same issue as mine. I you fix yours I fix mine too (or the other way around). I have seen a few similar posts on other forums same issue and they are all a dead end road.

 

So let’s keep going and fix the bikes!
 

It certainly helps if you can bounce the ball back and forward. It’s almost if the devil answers your call. Yes this problem in the bike is a little devil. 
 

My bike looses power above 70mph which is not much on the German autobahn.

 

BB 

Morning  Beamer boy

 

We are not going to fix this problem until the original poster of this thread  returns & tells us what he found or where he is at testing wise. As I mentioned above,  last thing I had him do was do a TPS output sweep & haven't heard back from him since. 

 

If you want to address your problem then start a new thread about YOUR problem so we don't hijack this thread from the OP's problem into your problem (not fair to the original poster) .  If your problem is only above 70 mph then it sounds slightly different  than  the OP's issue here. I have some ideas for you to look at but I won't address them in this thread as that would be hijacking the original thread away from the original poster's complaint. 

 

So start a new thread on  your problem, or send me a private message through this site & we can deal with your problem through private messages. 

[Beamer boy]

Hi dirt rider,

 

I got a new TPS installed on my bike made no difference at all. There is no gap in the voltage and both potentiometers are coming into the Motronic.

 

Okay on fixing the issue with the other bike. Not planning to hijack this topic.

But if you do happen to fix the other bike

one day than I would love to hear from you.

 

O yes I checked my emergency stop switch or what ever you call it and I noticed a lot of grease in this area. 
got the Switch out and cleaned More.

Can’t do any testing yet with the bike because the cylinder head is off.

 

I am running out of ideas and or suggestions to help you further with this error. 
 

BB

 

 

[dirtrider]

55 minutes ago, Beamer boy said:

Hi dirt rider,

 

I got a new TPS installed on my bike made no difference at all. There is no gap in the voltage and both potentiometers are coming into the Motronic.

 

Okay on fixing the issue with the other bike. Not planning to hijack this topic.

But if you do happen to fix the other bike

one day than I would love to hear from you.

 

O yes I checked my emergency stop switch or what ever you call it and I noticed a lot of grease in this area. 
got the Switch out and cleaned More.

Can’t do any testing yet with the bike because the cylinder head is off.

 

I am running out of ideas and or suggestions to help you further with this error. 
 

BB

 

 

Afternoon BB 

 

I got your PM so there is list of things to check on your private messages. 

[Beamer boy]

Thank you Dirt Rider,

 

Much appreciated.

 

BB