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2004 R1150 Starting Issue

jlevee

Geek
I have a 2004 R1150 Rockster. Recently it has been having issues starting in colder weather (I am in Arizona). I have noticed that if parked in the sun, or recently ridden starts fine. But in the mornings (<70 degrees it does not want to start) The starter was replaced last year, the battery yesterday. Still have the issue this morning. Any ideas?
 
I assume your start process is hold the "choke" in the full up position until it catches and then let the lever drop back to the mid point?

It's hard to say for sure what's going on. At colder temperatures, the Motronic normally commands a lot more fuel by turning the injectors on for 50% or a hundred percent longer than when warm.

So it could the Oil Temperature sensor is not working correctly. Does it register correctly after starting as the bike warms up? I don't think these fail often.

While it's cold, while you crank, you could spray some starting fluid into the intake by pulling the air filter cover. It it starts right away, suspect fuel flow or Oil Temp sensor.

It could also be that your plugs' gap has grown too large. How long has it been since you've checked the gap?

Fuel issues can run the gambit from clogged filter to injector fouling, leaking fuel hoses in the tank, etc.

The other thing I noticed is that if the battery voltage is low while cranking the injectors get very slow and don't deliver as much fuel. You could measure battery voltage while you crank. Perhaps the starter is loading the battery too much.
 
It's also not unheard of for a new battery to be defective. Put a voltmeter on it and measure voltage while the starter is cranking; system voltage should remain above 10v.
 
Starting with & with out using the choke has shown to have no impact on starting the bike. (Or lack there of) And we are talking 65 degrees here, so choke should not be necessary. Up until this issue i rarely used the choke on it since i got it in 05.

Bike had a full service w/ new plugs back in April, with the starter being replaced as previously stated last November.

It should not be the battery. I was having the issue w/ the old battery & it had registered in the correct range, until the other day when my repeated attempts at starting it through out the day killed it.

I had mentally eliminated fuel issues/ fuel filter & line as the issue has persisted over several tanks of fuel.
 
"Choke" isn't necessary anyway. Its not a choke; its a fast idle device that keeps rpms up so a cold bike can warm up better. That's not your problem. Try unplugging the computer for a little while, then plug it back in and try a restart. Resist the temptation to twist the throttle while doing this.
 
"Choke" isn't necessary anyway. Its not a choke; its a fast idle device that keeps rpms up so a cold bike can warm up better. That's not your problem. Try unplugging the computer for a little while, then plug it back in and try a restart. Resist the temptation to twist the throttle while doing this.

:scratch
If you are advising a reset of the computer then the correct procedure (for an 1150) is to:
- pull fuse #5
- wait several minutes
- replace fuse #5
- turn on ignition but DO NOT start
- slowly twist the throttle lever fully open then back to fully closed 3 times
- turn off ignition
- start the bike as you normally would
 
It's cold, and the bike's in the garage. Decided to measure throttle opening at various positions after reading in my Rider's Manual that the correct starting procedure is to hold the "Choke" (i know it's not a choke but BMW calls it that in the book; all it does is open the throttle) all the way up until the engine starts, then release to Mid position.

Full Choke: 4.16 degrees throttle open
Mid Choke: 1.28 degrees
No Choke Idle: 0.32 degrees

Although only 65 degrees that's cold relative to an engine at operating temperature. When you hit the starter button the injectors, during "cold" start, squirt about 4X the fuel compared to warm idle.

The data below was taken in my 50 degree garage, the key line for this discussion is injection time. It's about 8 mS total on the left and about 3.5 mS total on the right. From each of those numbers subtract 2mS injector dead time and you get 6 mS compared to 1.5 mS. They dump that much fuel in because it doesn't atomize well when cold and some condenses on the valves and TB wall.

The R1150 injectors seem very sensitive to low voltage. Even at 12V versus 14V while charging they squirt about 7% less fuel. The right amount of fuel plus the right amount of air with god plugs starts most motors.

motroniccoldstartsequence.jpg
 
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I had mentally eliminated fuel issues/ fuel filter & line as the issue has persisted over several tanks of fuel.

Just one more thought, fuel filter or leaking hoses would persist over several tanks of fuel.

Try spraying some starter fluid in the intake while you crank. If it catches quickly that will let you know to investigate fuel issues.
 
I have a 2004 R1150 Rockster. Recently it has been having issues starting in colder weather (I am in Arizona). I have noticed that if parked in the sun, or recently ridden starts fine. But in the mornings (<70 degrees it does not want to start) The starter was replaced last year, the battery yesterday. Still have the issue this morning. Any ideas?

When did you last check your valve clearances?
 
I read this quickly so might have missed something but it is unclear to me if this is a cranking issue or just a starting issue. By cranking issue I mean slow labored cranking or normal robust cranking. That becomes one set of issues if it is cranking slowly.

On the other hand, if it is cranking normally but failing to start that becomes a separate set of issues, several that have been discussed here.

So which is it?
 
I read this quickly so might have missed something but it is unclear to me if this is a cranking issue or just a starting issue. By cranking issue I mean slow labored cranking or normal robust cranking. That becomes one set of issues if it is cranking slowly.

On the other hand, if it is cranking normally but failing to start that becomes a separate set of issues, several that have been discussed here.

So which is it?
Excellent question Paul.
 
Sorry for long to reply. Chrome keeps blocking me from the site do to a malware warning.

Valve clearances were checked back in April.

Cranking is normal, just failure to start.
 
Sorry for long to reply. Chrome keeps blocking me from the site do to a malware warning.

Valve clearances were checked back in April.

Cranking is normal, just failure to start.

time since last valve adjustment is irrelevant, only miles since adjustment matter.
(but unless something has gotten loose, i doubt that is the issue).
 
Issue seems solved. Apparently the issue was 'crappy gas'. Although I only use premium, about 6 months ago I switched gas stations, to support the corporation my sig other works for. Its quality was not the best & thus as time passed here was enough build up to cause issues starting when cold, but no other time. Simple solution to the issue some fuel Injector cleaner & no longer getting gas from them. Thanks for all the input/ideas
 
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