Stumble on cold starts

Hello all,

I've had my used 2015 RTW for just under a month now. At times on cold starts the engine cranks and does not fire immediately. Hold the button down for a bit and it sputters like it wants to fire, release and the rotation stops. Hit the start button again and then it fires right away. It dose not have any problems when warm. Have others experienced this?

Thank you,

Snowy.

My 2014 does the same thing every now and then.

Alan

Mine does that on occasion. If it does not start right away, I now just crack open the throttle a bit and it seems to help. At least it does not die after doing that.

Let me add that I LOVE starting this thing, especially cold. For some reason I get the feeling I am cranking over one of the old Radial aircraft engines. The sound it makes for about 1 or 2 seconds sounds just like them!

Happens occasionally on my '14 too...sounds pretty common.

Yes, I've experienced this fairly often. Always fires immediately on the second try.

Note that the owner's manual suggests a moderate throttle opening when cold starting, different than other F.I. engines I've experienced. This seems to diminish the frequency of the stumble.

This is what the manual says:

For cold starts and at low ambient temperatures: pull the lever to disengage the clutch and twist the throttle grip slightly.

Two maneuvers fixed this behavior for me in a '16 RT. I got them both from a different forum. The behavior I was experiencing seems identical to the OP's story. Second attempt started right up, first would typically sputter a little and fail. Once I had a genuine backfire!

1. Killing the motor w/ the kill switch rather than turning the ignition off w/ the key. Immediate cure, never had a stumbled start since.

2. Some mentioned my throttle was likely never 'calibrated'. Turn on the ignition and let the electronics fully boot up. Now roll the throttle to full on, then full off, and repeat it a couple of times. Now turn the ignition off. You should be good to go. Since doing this procedure I've not had one stumbled start. The throttle is a potentiometer of sorts and just needs to learn where full on and full off is, or so I surmised.

Cheers

Two maneuvers fixed this behavior for me in a '16 RT. I got them both from a different forum. The behavior I was experiencing seems identical to the OP's story. Second attempt started right up, first would typically sputter a little and fail. Once I had a genuine backfire!

 

1. Killing the motor w/ the kill switch rather than turning the ignition off w/ the key. Immediate cure, never had a stumbled start since.

 

2. Some mentioned my throttle was likely never 'calibrated'. Turn on the ignition and let the electronics fully boot up. Now roll the throttle to full on, then full off, and repeat it a couple of times. Now turn the ignition off. You should be good to go. Since doing this procedure I've not had one stumbled start. The throttle is a potentiometer of sorts and just needs to learn where full on and full off is, or so I surmised.

 

Cheers

Good input! I've seen this before, but had forgotten.

Mine does it as well. 2nd try fires right up.

GT

Same here with my 14 RTW. 2nd at bat and it fires right up.

Like the above post, I love the Boxer character big time. So so happy with this bike. And I had a few good ones.

Mine does it as well. 2nd try fires right up.

 

GT

You might follow this trick so she starts up on the first try:

http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=969054#Post969054

Same here with my 14 RTW. 2nd at bat and it fires right up.

Like the above post, I love the Boxer character big time. So so happy with this bike. And I had a few good ones.

You might follow this trick so she starts up on the first try:

http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=969054#Post969054

Mine does it as well. 2nd try fires right up.

 

GT

 

You might follow this trick so she starts up on the first try:

 

http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=969054#Post969054

Morning NoelCP

Just skip the part about the TPS re-learn as the newer 1200 waterheads don't have a learnable TPS-- but even if they did it would need a battery dis-connect for a few minutes first to put the fueling computer into a TPS learn mode.

Well your statement does not sound ambiguous, but it clearly doesn't fit with reports of applying this method which I got from another forum who noted it solves the issue, and was confirmed by not only the local shop which modified the procedure to stating it only require one full throttle on/off, and absolutely after doing this I never had another stumbled start. You're saying this is a red herring quite clearly.

Tell me if you will the source of this so that I can point the local shop to it? Since the throttle by wire system I'm assuming essentially a potentiometer of sorts it makes sense that a calibration routine should be there else the system can't tell where full on and full off would be, or so it seems. Hard to argue w/ success in more than one person's experience, eh?

 

Tell me if you will the source of this so that I can point the local shop to it? Since the throttle by wire system I'm assuming essentially a potentiometer of sorts it makes sense that a calibration routine should be there else the system can't tell where full on and full off would be, or so it seems. Hard to argue w/ success in more than one person's experience, eh?

Afternoon NoelCP

A number of confirming facts point this out--

(1)- IF a re-learn was required it would be in your riders manual under battery replace as the computer learning is lost after a battery disconnect (it is in the older hexhead riders manuals as a re-learn was required on those)

(2)- There is no re-learn in the wethead BMW service manual even after a full battery disconnect or a fueling computer replacement. (if it was needed it would for sure be part of the post service re-setting procedures)

(3)-If the re-learn is/was required & not done then the engine would run like crap until it was done (I keep hearing of poor starting on the wethead but never poor engine operation)

(4)- this is probably the most important. Even IF the wethead would require a re-learn it won't & can't do any throttle position re-learning UNTIL the fueling computer is put into a learning mode & THAT requires battery disconnect for a period of time or external hookup to put into learn mode. (if it didn't require this it would need to re-taught EVERY TIME the key was turned on).

D.R., Can you think of any reason the kill switch trick might make a difference?

This most assuredly is not the end of the world, from my perspective. It's mostly just a little odd. I follow the procedure in the manual, applying slight throttle, and this still occurs about nine times out of ten when it's a cold start.

D.R., Can you think of any reason the kill switch trick might make a difference?

 

This most assuredly is not the end of the world, from my perspective. It's mostly just a little odd. I follow the procedure in the manual, applying slight throttle, and this still occurs about nine times out of ten when it's a cold start.

Afternoon Mike

I can't think of anything substantially different about shutting off using the kill switch instead of the ign switch, BUT, I haven't had time to fully check the wiring schematics to see if using the kill switch shuts any of the electronics or shuts down the fueling system down in a different order.

My common sense tells me that using the kill switch to shut down should have no bearing on the re-start but until I verify (IF) the kill switch changes the shutdown order I can't comment with any confidence.

Don't lose any sleep over this. I'm just a little curious.

The good news is that the RT runs like a champ once she lights up. This one gets filed under "C" for "Character."

Don't lose any sleep over this. I'm just a little curious.

 

The good news is that the RT runs like a champ once she lights up. This one gets filed under "C" for "Character."

Evening Mike

If you have any gas stations in your area that sell ethanol free gasoline you might try a tank of that.

Ethanol free gasoline can improve cold/cool starting /staying running in some vehicles.

Don't lose any sleep over this. I'm just a little curious.

 

The good news is that the RT runs like a champ once she lights up. This one gets filed under "C" for "Character."

 

Evening Mike

 

If you have any gas stations in your area that sell ethanol free gasoline you might try a tank of that.

 

Ethanol free gasoline can improve cold/cool starting /staying running in some vehicles.

The evil is hard to avoid here, but whenever I have a choice I fill up with pure Dino-fuel.

 

A number of confirming facts point this out--

 

(1)- IF a re-learn was required it would be in your riders manual under battery replace as the computer learning is lost after a battery disconnect (it is in the older hexhead riders manuals as a re-learn was required on those)

 

(2)- There is no re-learn in the wethead BMW service manual even after a full battery disconnect or a fueling computer replacement. (if it was needed it would for sure be part of the post service re-setting procedures)

 

(3)-If the re-learn is/was required & not done then the engine would run like crap until it was done (I keep hearing of poor starting on the wethead but never poor engine operation)

 

(4)- this is probably the most important. Even IF the wethead would require a re-learn it won't & can't do any throttle position re-learning UNTIL the fueling computer is put into a learning mode & THAT requires battery disconnect for a period of time or external hookup to put into learn mode. (if it didn't require this it would need to re-taught EVERY TIME the key was turned on).

 

The premises you are basing your conclusions may be correct but the conclusions you draw absolutely do not follow from those facts alone I'm afraid. You are trying to deduce your way out of empirical evidence which is that absolutely shutdown switch resolves the issue per event, that is you need to do this every time you shut down the machine else you will find the stumbled start recurs. This is not only my experience. It was not until I did the calibration routine that I no longer needed to use the kill switch. With an 'n' of one, myself, we can chalk it up to happenstance perhaps, but not when several people discovered these tricks work.

Don't lose any sleep over this. I'm just a little curious.

 

The good news is that the RT runs like a champ once she lights up. This one gets filed under "C" for "Character."

Good Lord Mike, why don't you try first the kill switch maneuver and report back. And then, try the calibration routine and see if it holds up. Same here vast majority of the time the bike would not start on the first try until either of those tricks were applied--zero stumbled starts ever since--not one.

Noelcp, while I appreciate your enthusiasm, please consider facts above owner "reports". I can tell you that Dirtrider has a LOT more background, experience, access to BMW inside details, than you might imagine.

I tried the "kill switch" and learning process because I knew it could not hurt. I still, rarely, but still have to hit the starter the second time. IF I remember to crack the throttle it never dies. So, I think the "learning" and "kill switch" routine is a placebo effect based on my experience.

Just like having the oil a bit high in the sight glass. It is posted that there is a marked difference in shifting when lowered. I cannot see one bit of difference. Again, I suspect placebo effect.....

 

A number of confirming facts point this out--

 

(1)- IF a re-learn was required it would be in your riders manual under battery replace as the computer learning is lost after a battery disconnect (it is in the older hexhead riders manuals as a re-learn was required on those)

 

(2)- There is no re-learn in the wethead BMW service manual even after a full battery disconnect or a fueling computer replacement. (if it was needed it would for sure be part of the post service re-setting procedures)

 

(3)-If the re-learn is/was required & not done then the engine would run like crap until it was done (I keep hearing of poor starting on the wethead but never poor engine operation)

 

(4)- this is probably the most important. Even IF the wethead would require a re-learn it won't & can't do any throttle position re-learning UNTIL the fueling computer is put into a learning mode & THAT requires battery disconnect for a period of time or external hookup to put into learn mode. (if it didn't require this it would need to re-taught EVERY TIME the key was turned on).

 

The premises you are basing your conclusions may be correct but the conclusions you draw absolutely do not follow from those facts alone I'm afraid. You are trying to deduce your way out of empirical evidence which is that absolutely shutdown switch resolves the issue per event, that is you need to do this every time you shut down the machine else you will find the stumbled start recurs. This is not only my experience. It was not until I did the calibration routine that I no longer needed to use the kill switch. With an 'n' of one, myself, we can chalk it up to happenstance perhaps, but not when several people discovered these tricks work.

 

I wanted to test this out, and did the re-learn trick a few days ago. I can say with confidence that the re-learn sequence didn't do a thing for my RT.

 

After the failed throttle recalibration effort, which may have amounted to nothing more than some wrist exercise, I got her fired up and ultimately shut down with the kill switch. At that point he RT started right up, but it was a hot restart, so it may or may not have an effect. I'll give it a try tomorrow (my RT and I have been separated for a few days) to see if it's solved the cold start stumble.

 

So, at least in my situation, what D.R. has written regarding throttle recalibration seems to be born out by experience. I'll report back once I've tried a real cold start or two after shutting down with the kill switch.

 

NoelCP, I am giving the two strategies a shot, just in the reverse order of what you suggested. I'll know tomorrow if the kill switch trick works. If I have better luck with using the kill switch, that might suggest that the recalibration thing is just a placebo, and that there's something about using the kill switch that fixes it.

When I bought my bike last fall, it always started first time. It had 5700 miles on the clock.

Then I posted here that mine always starts first try. Within a week, I started having issues on hotter days, say above 80, when the bike has been setting for a few hours, it'll take two tries to start. On cold bike starts below 70, first try. Cold bike above 70, "usually" 2 tries. I blame myself for posting on the forum, I jinxed it.

I've always done the kill switch to shut off the bike. I did recently try the throttle trick and turned the bike off. No change for me.

I'm chalking it up to a personality quirk of the bike. It doesn't bother me much. I'll probably mention it to the dealer at my next service.

Terry: it's one thing to say there is no published calibration routine {fact] but quite another to say because of that there is no such thing. I would agree there ought to be, but nothing necessary about it. It's even possible BMW engineers were not aware this might be possible! Sometimes computer code has unintended consequences.

Of the two suggested fixes I am 100% confident in the kill switch method. I did this multiple times using the kill switch and using the ignition key and every single time demonstrated the efficacy of the kill switch. This is the source of the enthusiasm. Not pretending to explain why, just what happens. Just because this is not published in rider and service manuals does not invalidate the experience. And don't forget I got this from others who experienced the very same thing and passed it on.

The calibration routine very clearly in my mind could have been a red herring. Also, there is nothing that says all bikes will be identical and that there is only one cause for stumbled starts. It is entirely possible that for certain conditions something in the process of using the kill switch solves the issue, but as I say in my experience 100% confirmation using it fixed it, not didn't. I began looking into the situation when I stopped for a 5 min period, got back to warmed bike, attempted to start my '16 RT, it wouldn't start on the first try as had been the case, and on the second try got a substantial backfire. Under the assumption that backfires aren't the best thing, I began searching to see if others experienced this and if there were potential solutions.

In the interest of science, I did my first post-kill switch cold engine startup this evening and . . . .

The RT fired up instantly, on the first attempt. I don't recall it doing this on a cold start since I purchased it this spring; it's been a consistent second-attempt starting routine.

I'll continue to use the kill switch shutoff routine, to see if this is an anomaly or if it really has fixed the problem for me. So, based on my scientific study, the "throttle calibration trick" didn't do anything. However, the kill switch routine resolved the issue . . . at least the first time. I'll be interested to see how many others can repeat this result.

So I do not have this issue as of yet. However I use my kick stand to shut my bike of. It has been my habit with every bike I own. Put the kick stand down to stop the motor then hit the power switch to shut it down. I never use the push button start/stop to shut the bike down initially. Kick stand then push button.

Mike bike has started first try every try.

In the interest of science, I did my first post-kill switch cold engine startup this evening and . . . .

 

The RT fired up instantly, on the first attempt. I don't recall it doing this on a cold start since I purchased it this spring; it's been a consistent second-attempt starting routine.

 

I'll continue to use the kill switch shutoff routine, to see if this is an anomaly or if it really has fixed the problem for me. So, based on my scientific study, the "throttle calibration trick" didn't do anything. However, the kill switch routine resolved the issue . . . at least the first time. I'll be interested to see how many others can repeat this result.

Here is another data point - like LAF, I had always use the side-stand deployment to shut off the motor, since I always park the bike in 1st. My '15 RT had always start right up within a rev. or two, hot or cold, and never an issue. The subject of this thread had started in the other forum a while ago, and I had read it with interests, and had files things away in my mind as interesting information.

Now, about a month or so ago, for some reasons, I rode the RT into my garage and (I don't recall why) but shut down the bike while it was running with the main on/off switch. The next day, when I got on the RT and press the start button, it did exactly what some of you had experienced and it took 2 attempts to start up. No problems on subsequent hot-starts, but the following day it did the same thing again on cold start! That was when it dawned on me that shutting down with the main on/off switch might have done something, as suggested in the thread that I had read. So, the next time that I first start up the RT, I did what one person suggested, and that was to push the kill switch to kill, and then back to on before starting. The RT started right up as always in the past without that hesitation. I did NOT have to repeat the kill switch actions on subsequent cold starts, and the hesitation had not returned!

Dirtrider - I agree with your assessment 100% regarding the throttle relearning! It is apples and pears, if you try to compare the throttle system of the new wetheads to the older RTs! The wetheads uses ride-by-wire system, which means that there is (are?) digital encoder(s?) at the handle (I am too lazy to look it up on my DVD), and the throttle servo probably has a "hard" home position on its encoder, ergo nothing to "learn". Great point about the owner's manual!!

In the interest of science, I did my first post-kill switch cold engine startup this evening and . . . .

 

The RT fired up instantly, on the first attempt. I don't recall it doing this on a cold start since I purchased it this spring; it's been a consistent second-attempt starting routine.

You're welcome--it's been repeated elsewhere which is why it was passed on here.

Now, about a month or so ago, for some reasons, I rode the RT into my garage and (I don't recall why) but shut down the bike while it was running with the main on/off switch. The next day, when I got on the RT and press the start button, it did exactly what some of you had experienced and it took 2 attempts to start up. No problems on subsequent hot-starts, but the following day it did the same thing again on cold start! That was when it dawned on me that shutting down with the main on/off switch might have done something, as suggested in the thread that I had read.

 

I talked to a certified BMW mechanic w/ over 20y at it today about this. He said absolutely the computer in modern RT is continually in learning mode about not just the throttle on/off but many other elements that might vary from rider to rider beyond just environmental conditions. His guess on why it might develop over time w/ people inclined to use the key to turn off the bike is that they might have a very subtle throttle-on secondary to keeping the front brake pulled while using the left hand to reach for the key so that at that moment the computer has just relearned a new throttle-off position. This makes some sense also about why, seemingly randomly, the bike will start failing to start on the first try as it was inadvertently reset unknowingly by the rider thru an action such as this. I asked if he could point me to a service manual comment about this and he said nope, you won't find it as there are lots of things the computer is continually learning from that is just built-in, and so are not 'procedures' per se. It sounds like you would need to have access to the entire logic scheme the computer was programmed to execute to really see if this story is fact, fiction, or a little of both.

 

I know for me, having done the kill switch trick maybe 50 times w/ success, then would occasionally use the key and the issue would resume after a start or two or three, and it was not until I did the suggested reprogramming maneuver that I never had to do the kill switch trick again. This story is 100% factual ;o)

Now, about a month or so ago, for some reasons, I rode the RT into my garage and (I don't recall why) but shut down the bike while it was running with the main on/off switch. The next day, when I got on the RT and press the start button, it did exactly what some of you had experienced and it took 2 attempts to start up. No problems on subsequent hot-starts, but the following day it did the same thing again on cold start! That was when it dawned on me that shutting down with the main on/off switch might have done something, as suggested in the thread that I had read.

 

I talked to a certified BMW mechanic w/ over 20y at it today about this. He said absolutely the computer in modern RT is continually in learning mode about not just the throttle on/off but many other elements that might vary from rider to rider beyond just environmental conditions. His guess on why it might develop over time w/ people inclined to use the key to turn off the bike is that they might have a very subtle throttle-on secondary to keeping the front brake pulled while using the left hand to reach for the key so that at that moment the computer has just relearned a new throttle-off position. This makes some sense also about why, seemingly randomly, the bike will start failing to start on the first try as it was inadvertently reset unknowingly by the rider thru an action such as this. I asked if he could point me to a service manual comment about this and he said nope, you won't find it as there are lots of things the computer is continually learning from that is just built-in, and so are not 'procedures' per se. It sounds like you would need to have access to the entire logic scheme the computer was programmed to execute to really see if this story is fact, fiction, or a little of both.

 

I know for me, having done the kill switch trick maybe 50 times w/ success, then would occasionally use the key and the issue would resume after a start or two or three, and it was not until I did the suggested reprogramming maneuver that I never had to do the kill switch trick again. This story is 100% factual ;o)

 

Evening NoelCP

 

 

Sorry but I just don't buy his assumption. Your BMW expert might want to study the system a bit more before he makes unrealistic statements.

 

While he is correct in that the fueling computer learns some things (like fueling adaptives for instance) but it can't learn or re-learn throttle position without FIRST putting the computer into a learning mode (that would be IF the computer even had a throttle position learning mode)

 

Even IF he was correct it would not make one iota of difference for engine starting as the throttle plates are firmly on the idle stop screws for cold start as long as the twist grip isn't held open.

 

If BMW made the fueling computer able to re-learn throttle position without putting it into a learning mode then a rider would have to re-teach the throttle position after every new key on or after every engine stall.

 

If there was an automatic learning ability (there isn't) & the rider started the engine but didn't go to wide open throttle at key-on to teach it WOT then how could he ever get WOT to pass someone without teaching it first?

I don't know but it seems like the computer has to have a learning mode for some things, and there is nothing necessary about having to have a learning mode be something that is turned on or off--it may be always on, always subject to new learning.

His explanation went into much more detail about how current computer is reading all sorts of attributes of rider behavior, braking behavior, clutch use, all sorts of things. I believe he also was saying the reason the shutdown switch resolves the issue has to do with excluding throttle position at the time the engine is shutdown which then sets the throttle-off to zero, whereas when the key is used the hand may well have subtle pressure, or not, with for example the right hand squeezing the front brake. This dynamic is compatible w/ the fact that the issue crops up for some, not all, at random times, etc, and that all reports I've seen regarding the kill switch trick have proven effective.

With due respect it seems much of your position is based on deduction from factual premises you are aware of, which is great of course, unless you don't have all the relevant facts, then it's potentially spurious. Perhaps the computer does more than you're aware of on this very issue? What's really called for is a look at the entire logic scheme of the computer and everything it's connected to.

Morning NoelCP

Wow! what a system/ BMW won't even allow or trust the rider to re-set the oil service light but according to you WILL allow an untrained rider to re-set & teach the throttle positions. All this with no information on how to do it in the riders manual.

OK I get it, BMW has no idea on how their computer system works. I'm surprised that people even ride the newer BMW's as the computer might learn that it doesn't like the rider & turn the computerized brakes off, or learn to go to wide open throttle then keep it there.

Or a rider goes to pull out into traffic & the bike just slowly rolls out with no power as the rider didn't teach it how to open the throttle & the computer didn't have time to learn that on it's own.

Even worse, if a rider never goes to wide open throttle then the computer would never learn where that was so the rider could never reach wide open throttle without stopping, then turning the key on & doing the twist grip twist full open to teach it.

Or if a rider stalls the bike with the throttle slightly open then the computer would not know where idle was & keep the engine from idling until the rider stopped & turned the key on & taught it where idle was. (seems like a very strange & dangerous design to me but what do I know as I have only worked with computer controlled engine systems for 47 years)

Even stranger yet, this only works for some riders as the posters above found no gain in doing a throttle re-learn. (I wonder how it knows who to learn for & who not to learn for?)

Have you called or E-mailed BMW to tell them that you know more about their 1200 W/C computer system than they do & how they screwed up their rider's manuals & service manuals by not including your throttle teaching findings?

OK, let's see you have one example from one person who has apparently not experienced improvement with this. Is it possible there is more than one reason the stumbled start issue happens, of course!

Others passed this on to me before i every asked the guy who works daily on BMW's and has for two decades and says unequivocally what I described or paraphrased. Once again, you don't really KNOW, you're trying to GUESS from what you think you know.

Alright, since you can deduce everything from a few known facts, WHY does the kill switch maneuver resolve the issue? You've got 47y at it, what's the reason? Was this an intentional design by BMW? I don't think so, it's a accidental finding for what we could describe is likely a bug in the code design of the computer.

Here's the truth of the matter: neither you nor I really know what's happening and why on this. You're trying to guess which is all you can do. I"m reporting what happened to me: repeated verification shutdown switch resolves the issue, use the key ONCE and the stumbled start resumes the very next attempt. Multiple times I did this to prove this wasn't coincidental. Then someone tells me about this throttle relearn. The very next time I never had another stumbled start. Pretty compelling don't you think?

So far, once again, you're offering ONLY guesses from how you THINK reality OUGHT TO BE. That's all well and good but in the end computer code and behavior is sometimes exceedingly hard to predict all possible interactions and outcomes, and why patches have to be developed.

Once again, ORACLE, (ahh, OK I see) you're back to saying BMW should have published this in the rider manual. Maybe they didn't realize this could happen eh? Do you think they DESIGNED IN something the kill switch shutoff would cure? Really? Why then didn't they publish it in the rider manual?

The stumbled start cured by the kill switch very likely is an unexpected fix a rider accidentally discovered for a problem that develops apparently somewhat frequently. If BMW knew about this it would seem they could resolve the issue w/ a software change, or perhaps the issue is so embedded in the entire architecture of all the hardware involved it's not practical to fix w/ only a software change so will need to wait until next generation design.

 

Alright, since you can deduce everything from a few known facts, WHY does the kill switch maneuver resolve the issue? You've got 47y at it, what's the reason? Was this an intentional design by BMW? I don't think so, it's a accidental finding for what we could describe is likely a bug in the code design of the computer.

 

Here's the truth of the matter: neither you nor I really know what's happening and why on this. You're trying to guess which is all you can do. I"m reporting what happened to me: repeated verification shutdown switch resolves the issue, use the key ONCE and the stumbled start resumes the very next attempt. Multiple times I did this to prove this wasn't coincidental. Then someone tells me about this throttle relearn. The very next time I never had another stumbled start. Pretty compelling don't you think?

 

So far, once again, you're offering ONLY guesses from how you THINK reality OUGHT TO BE. That's all well and good but in the end computer code and behavior is sometimes exceedingly hard to predict all possible interactions and outcomes. YOU contact BMW if you care to learn the truth about this, because until then it's primarily just you're guess which so far offered ZERO cure for this issue.

Morning NoelCP

I don't know that using the kill switch maneuver resolves the issue. At this point it is just internet lore. I DO know that the kill switch interfaces with the fueling computer differently than the ign switch input so, in THEORY, it c-o-u-l-d change the sequence of shutdown (such as shutting off the fuel pump but leaving the spark system intact).

Until I FULLY study & understand the way the kill switch vs the ign switch forces engine shutdown I can't offer any valid reasons one way or the other. I do know for a fact that using the kill switch for shut down didn't help my friends 2016 1200RT W/C cold start any better.

I can say (based on a long term working knowledge of how the BMW system works) that teaching the BMW throttle system with ONLY a key-on first is fruitless & a waste of time)-- Same as stepping in front of an 80 mph truck, I haven't ever done it myself but I know from common sense on how things work that it shouldn't be done. Or drinking ethylene glycol, again I haven't done it, but common sense facts tell my it can't be a good thing.

My 14RT started to do this occasionally after 40,000 miles maybe a dozen times in the last 14,000 miles a little irritating but no big deal.

Morning NoelCP,

I don't know that using the kill switch maneuver resolves the issue. At this point it is just internet lore.

I'm afraid you're dead wrong on this one. This has been validated by multiple parties and when you validate something over and over what begins as for example internet lore becomes reliable information. I don't know anything about your friend, if you mean Mike he re-validated the issue w/ the kill switch but apparently not the throttle relearn 'trick'. So far I'll grant you there is not enough empirical proof on the throttle relearn, but there clearly is on the kill switch shutdown routine. There is NOTHING that says if 9 of 10 wet heads that stumble start are resolved by using the kill switch that all causes of stumbled starts are the same right? Sure.

I think for anyone w/ 'oracle' level knowledge the temptation would be to depend a little too much on a priori. With computer & code connected to multiple sensors problems will happen and even the very software engineers who designed it will discover unintended outcomes, hence the inevitable software updates as new information is learned.

Kill switch to power off hasn't fixed my problem. I was doing that long before I had an issue as well.

And I have keyless, but I never turn it off with that or sidestand. Always kill switch.

Morning NoelCP,

I don't know that using the kill switch maneuver resolves the issue. At this point it is just internet lore.

 

I'm afraid you're dead wrong on this one. This has been validated by multiple parties and when you validate something over and over what begins as for example internet lore becomes reliable information.

Afternoon NoelCP

See post just above this one!

 

Alright, since you can deduce everything from a few known facts, WHY does the kill switch maneuver resolve the issue? You've got 47y at it, what's the reason? Was this an intentional design by BMW? I don't think so, it's a accidental finding for what we could describe is likely a bug in the code design of the computer.

 

Here's the truth of the matter: neither you nor I really know what's happening and why on this. You're trying to guess which is all you can do. I"m reporting what happened to me: repeated verification shutdown switch resolves the issue, use the key ONCE and the stumbled start resumes the very next attempt. Multiple times I did this to prove this wasn't coincidental. Then someone tells me about this throttle relearn. The very next time I never had another stumbled start. Pretty compelling don't you think?

 

So far, once again, you're offering ONLY guesses from how you THINK reality OUGHT TO BE. That's all well and good but in the end computer code and behavior is sometimes exceedingly hard to predict all possible interactions and outcomes. YOU contact BMW if you care to learn the truth about this, because until then it's primarily just you're guess which so far offered ZERO cure for this issue.

 

Morning NoelCP

 

I don't know that using the kill switch maneuver resolves the issue. At this point it is just internet lore. I DO know that the kill switch interfaces with the fueling computer differently than the ign switch input so, in THEORY, it c-o-u-l-d change the sequence of shutdown (such as shutting off the fuel pump but leaving the spark system intact).

Until I FULLY study & understand the way the kill switch vs the ign switch forces engine shutdown I can't offer any valid reasons one way or the other. I do know for a fact that using the kill switch for shut down didn't help my friends 2016 1200RT W/C cold start any better.

 

I can say (based on a long term working knowledge of how the BMW system works) that teaching the BMW throttle system with ONLY a key-on first is fruitless & a waste of time)-- Same as stepping in front of an 80 mph truck, I haven't ever done it myself but I know from common sense on how things work that it shouldn't be done. Or drinking ethylene glycol, again I haven't done it, but common sense facts tell my it can't be a good thing.

I'd like to hear what you find out. We just have a couple of data points now, but it (the old kill switch trick, that is) appears to work for some.

I have supreme confidence that you're pretty much the man for this task; of all the tech nerds who have occasioned these pages over the past 18 years, you're on top of the pile. You are a god.

NoelCP, thanks for getting us started down the road of discussing this. As I said, it never got to the point of an annoyance for me, but it is a curious tendency for such a pricey motorcycle. It's nice to experience the RT firing right up; somehow it just feels more proper for a sophisticated machine.

I just hijack this from the MOA forum credit goes to Dave Nicholls,Teulon Manitoba - Canada:

I have 70,000 kms on my bike now and the intake valve have tightened a touch and the exhaust haven't moved at all. I would suggest that before you get too worried about the valve clearance check the cam timing. It is a very common issue with these engines that he cam timing drifts off and could cause incorrect reading on valve clearance. The process is simple and is made easier by using a valve locking block and crank locking pin, both available from you local BMW dealer for a reasonable price. Usually one of the indicators of timing drift is the bike won't start on first try, but fires right up after the second. This is because the cam position sensor tells the fuel management that the valves are not in the correct position and no fuel is supplied to the injectors.

Jay

NoelCP, thanks for getting us started down the road of discussing this. As I said, it never got to the point of an annoyance for me, but it is a curious tendency for such a pricey motorcycle. It's nice to experience the RT firing right up; somehow it just feels more proper for a sophisticated machine.

Well, it's new for this forum but not in some others. I think it will be multifactorial, there will be more than one cause and therefore resolution or workaround. Definitely an annoyance to have a brand new really nice machine exhibit this and I was very grateful for both tips as I haven't had a stumbled start since, and that's in 11K miles or so:

bushbikie

Join Date: Dec 2015

Location: SE Qld, Oz.

Posts: 17

Re: RTLC: do you always twist throttle some before hitting the starter button?

I had the same problem when the engine was cold, regardless of ambient temperature, would never fire on first crank, but would ALWAYS fire on the second crank. Mind you, ambient temp where I'm at has been from 20-35°C when I've tried to start the bike.

Someone on this forum posted the following "fix" - Kudos to them!

I have been using it and the bike now fires up first time, every time:

1. Ignition is Off.

2. Turn Kill Switch (right hand switch block) to Off, if not already Off.

3. Turn ignition On

4. Wait until the Speedo/Tacho gauges rotate and return to zero.

5. Now start the engine.

Dunno why it works, but it does. Probably just one of those flukey software bugs.

Radix

Member

Radix's Avatar

Join Date: Oct 2015

Posts: 35

Re: RTLC: do you always twist throttle some before hitting the starter button?

Quote:

Originally Posted by Radix View Post

If my 2016 RTW has been sitting a while, it does not want to start, no throttle--even in mild Southern Calif. temperatures. The owner's manual says you should give it a little throttle to help it out. I do this, and it starts right away. If I've been riding, it is not necessary, and I keep the throttle closed to start the bike.

Regards,

--Radix

I should note that this was true, but the behavior of the bike changed and I was confronted with the no-start-the-first-time syndrome. As noted in a later post, this is now cured by using the kill switch, in which case it starts on the first push of the starter button

Regards All,

--Radix

taz68

Junior Member

Join Date: Apr 2013

Location: Phoenix, AZ, USA

Posts: 8

R1200RTW Cold Start Anomaly

Hello all. Mine is a 2015 R1200RT that I purchased in late Sept. Currently has 3.6k mi. Previously owned a '10 RT for 4 1/2yrs.

The bike pretty much runs perfectly except on a cold start; usually the first start of the day. On the initial start attempt, the bike will crank but not start. It always starts right up on the second attempt. This even works if I just bump the starter for a second on the first try.

This has occurred consistently is temps from 40 to 90 deg. Warm starts are no problem.

It seems as though some component or program is resetting after the 1st attempt. BTW: I always let the gauges run thru their test cycle before starting.

I asked the dealer about this when I brought the bike in for its 600mi service. They placed the bike on their code reader and said that its not showing any problems. Just keep riding the bike and let them know if the issue persists.

Along this line, I discovered by accident that if I place the kill switch to stop before pushing the ignition button, turn on the ignition, let the gauges cycle, and then start the bike, it fires right up. I've pretty much been starting the bike since using this method.

I just hijack this from the MOA forum credit goes to Dave Nicholls,Teulon Manitoba - Canada:

I have 70,000 kms on my bike now and the intake valve have tightened a touch and the exhaust haven't moved at all. I would suggest that before you get too worried about the valve clearance check the cam timing. It is a very common issue with these engines that he cam timing drifts off and could cause incorrect reading on valve clearance. The process is simple and is made easier by using a valve locking block and crank locking pin, both available from you local BMW dealer for a reasonable price. Usually one of the indicators of timing drift is the bike won't start on first try, but fires right up after the second. This is because the cam position sensor tells the fuel management that the valves are not in the correct position and no fuel is supplied to the injectors.

 

Jay

Sounds plausible for at least one cause or at least co-factor for the issue manifesting.

I believe this "work around" was discussed here at some point a while back, but it may have been on another forum. Anyway, good to inform/remind folks here. Apparently at least a handful of us have experienced the stumble, but there have been very few reports; the fact that it's not reported more often makes me suspect that it's not a universal issue.

One of the best ways to get to the bottom of this problem would be to have a GS-911 set up on one of the problem bikes, logging ALL realtime values to a CSV file for every start. Then do the same with the special sequence that works, and compare the data files. I'd be happy to analyze them.

Other than wear or stretching of the timing chain and sprockets what is the mechanism that would cause the valve timing to drift? Assuming it did drift how would you adjust it?

Geoff

Other than wear or stretching of the timing chain and sprockets what is the mechanism that would cause the valve timing to drift? Assuming it did drift how would you adjust it?

Morning Geoff

On the wethead 1200 bikes the cams are attached to the drive gears basically by friction (a bolt & a friction washer). A special tool is used to hold the cams in perfect alignment to each other & at a perfect timing position as the bolts are tightened down.

While it is possible for the cams (or in this case only one cam as only one cam of the 4 has the timing reluctor on it) to slip or migrate it isn't a common thing & FOR SURE not every difficult starting W/C 1200 has had cam position migration.

The common sense on this tells us that cam (reluctor) position has no effect on fuel being supplied to the injectors as the fuel rails pressurize at first key on regardless of the cam position.

The other common sense thing tells us that IF a cam has slipped enough to cause starting issues (fuel sprayed at the incorrect timing) it would also be far enough off to cause runability issues. I have yet to hear of a reluctant starting W/C bike to have runability or performance issues.

Even IF the initial starting fuel is injected at a slightly wrong time the engine should still start. Might not run real crisp right after starting or maybe start then poor cold idle but it should at least try to fire off.

In any case you don't need the special alignment tool to CHECK the cam reluctor position as there is an arrow & alignment mark that lines up at proper cam sensor timing.

OK thanks, I was just wondering since as far as I know there's no BMW maintenance item that requires a check on the valve timing. Under normal circumstances this would I guess only be necessary if the top end valve train was dismantled for some reason. My 2014 R1200RT has now covered nearly 28,000 miles and very occasionally I have experience this "second time start" problem, but mostly it just starts. One thing I do wonder about is the decompressor mechanism that's fitted to the front exhaust cam on each side, this seems to prevent the exhaust valve from closing at very low cranking speeds, relieving the load on the starter, now if that was just on the point of operating...?

Geoff

Originally Posted By: hefy_jefy

One thing I do wonder about is the decompressor mechanism that's fitted to the front exhaust cam on each side, this seems to prevent the exhaust valve from closing at very low cranking speeds, relieving the load on the starter, now if that was just on the point of operating...?

Evening Geoff

That is a thought-- I have seen the centrifugal valve lift compression release fail on the KLR 650's & if it fails in the non-working position it will barely crank over & if it fails in the valve lift position the thing will crank like crazy but have a difficult time firing with enough power to stay running.

I do have a difficult time believing that both side decompressors can fail on the same bike at the same time so that would probably leave across the board low cranking RPM's as about the only way both sides could fail on this many bikes.

I guess it would be easy enough to test using a compression tester-- If it won't make decent compression on the first cranking try but will on the 2nd cranking try then you might have found the smoking gun.

With all the cold start complaints it is very difficult to believe that BMW hasn't issued a service bulletin about this if the problem was even remotely related to the auto decompressors.

_________________________

Originally Posted By: hefy_jefy

One thing I do wonder about is the decompressor mechanism that's fitted to the front exhaust cam on each side, this seems to prevent the exhaust valve from closing at very low cranking speeds, relieving the load on the starter, now if that was just on the point of operating...?

 

 

 

Evening Geoff

 

That is a thought-- I have seen the centrifugal valve lift compression release fail on the KLR 650's & if it fails in the non-working position it will barely crank over & if it fails in the valve lift position the thing will crank like crazy but have a difficult time firing with enough power to stay running.

 

I do have a difficult time believing that both side decompressors can fail on the same bike at the same time so that would probably leave across the board low cranking RPM's as about the only way both sides could fail on this many bikes.

 

I guess it would be easy enough to test using a compression tester-- If it won't make decent compression on the first cranking try but will on the 2nd cranking try then you might have found the smoking gun.

 

With all the cold start complaints it is very difficult to believe that BMW hasn't issued a service bulletin about this if the problem was even remotely related to the auto decompressors.

_________________________

I doubt that this is the cause! The symptom is similar to having low battery voltage problem, and the engine seem to crank slower than normal. I know that it isn't the battery, in the few times that it had happened to me because one of my routine is to plug in a maintaining charger as soon as the bike is parked in the garage. OK, so it isn't definitive, but the fact that the symptom went completely away and the bike started quite normally subsequently seem to point in the direction that the battery is OK.