Help with r12r low throttle response issue

[Bob Ain't Stoppin']

Just a thought, but I would think our only input for changing the fuel cut off / throttle abruptness would be at the tps. Slight changes there would alter the throttle position where the cutoff takes place. Might be worth a try, but if you do, be sure to write down every step you take so you can go back to original if needed.

[moto-m]

It's interesting what you say about the difference between your bike and your friend's GS.

How do the tick-over RPM figures compare on the two machines? Is it possible that your bike's tick-over is set at a lower figure? If so this could cause a sharper, more sudden deceleration when the throttle is closed espiecially if your engine has relatively low miles compared to the GS.

Mike

Cheshire UK

[Invertedmike]

The idle on my r1200r is as specified in the manual. A very consistent 1100rpm. The same as my buddy's 1200GS. Interesting point about the idle setting but there was no dissimilarity there. My bike is actually more broken in with almost 80,000km on it now.

The TPS is a component I know little about. I've ordered a service manual but don't have it yet. Is this sensor adjustable or does it just send out different voltages as the throttle cable moves?

An interesting observation I note about this throttle cut issue at low power is the fact that I have very little to no travel left in the throttle tube at these low cruise speeds (like 40kph in second gear). The moment I release some of the throttle from that speed, I am crossing the idle power threshold. It feels to me that I should have at least a bit more travel left even at that low power/speed until hitting the idle position. If this idle threshold is actually adjustable (like at the TPS), I suspect the sudden jolt into idle from these slow cruise speeds could be avoided. On my friend's 1200 I think I had some more travel available before hitting the idle position in the throttle travel.

Is it possible the TPS could go out of adjustment? or if not adjustable become defective? Interesting possibility.


Mike

[KMalo]

The TPS is a component I know little about. I've ordered a service manual but don't have it yet. Is this sensor adjustable or does it just send out different voltages as the throttle cable moves?

Is it possible the TPS could go out of adjustment? or if not adjustable become defective? Interesting possibility.

Mike

Mike,

The TPS is an adjustable part (at least on most other FI bikes). I can tell you that the TPS on my Guzzi Cal EV was off and made the bike almost unmanageable at low speeds. I needed a replacement TPS, had it adjusted by a competent mechanic, and it was like having a new bike!

It's pretty well known within the Guzzi community that having a good tech work on your bike makes all the difference in the world -- starting with proper initial set-up at delivery. I'm wondering if this is the situation with our R12Rs, since some of us are happy with the bikes as is and others have great difficulty without add-ons.

Just a thought!

Chuck

[David R]

Disconnect battery ground for five minutes. Key off. Reconnect. Key on twist throttle three times from all the way off to all the way full. Key off. Start bike. Your TPS is now reset along with the computer. This is all you can do for that.

Throttle sync should be checked with a proper tool. Once you know if its correct or not you can decide on what is next.

Edit: I know the TBs don't usually get out of whack. Can't rule it out until its checked.

[Invertedmike]

The valves and TB sync were completed at the 60K maintenance interval at a BMW shop through the previous owner. I will be doing this service again early next season when it warms back up. I would be amazed that the TB sync would cause such a sudden non-linear lurch at the edge of idle. However it is certainly on my list of maintenance to perform next before giving up and taking it to a technician.

The battery disconnect TPS reset was one of the first things I did to troubleshoot. No difference unfortunately.

It's becoming evident that this extreme issue I'm having is not common with a simple solution. Hopefully BMW diagnostic equipment and/or an experienced technician will be able to clean this up.

It was worth a try to scour the forums to try and solve it myself with help.

Thanks anyway

Mike

[moto-m]

Hi Mike

I'm sure that you have the perseverance to see this to a satisfactory conclusion and I hope that you will get back with whatever turns out to be the final solution - I'm intrigued to know the outcome - Good luck.

Mike

Cheshire UK

[Bob Ain't Stoppin']

MIke, I have not worked on the 1200 motor/tps. But! With the 1100 motor we had resources such as the famous Lentini 0=0 articles. The tps should be adjustable and there should be a spec as to the proper voltage it sends to the computer at idle. At some specific voltage (along with other inputs such as room), the computer knows to cut the fuel for deceleration. If your tps was out of adjustment, this would happen at the wrong time and could produce your issues. Perhaps poking around the moa or ibmwr sites would provide you with the info you need to check this out.

With my 1100RS, I made huge improvements to the operation by doing exactly this. TPS adjustment smoothed out the dreaded surge and made for a much better running bike with no off idle lurch. Will a bmw tech do this for you? Who knows? I'd be real happy to hear you found the problem and fixed it.

edit: room = rpm (Stupid spell check!)

[deilenberger]

I think a bit of knowledge about the R1200 fuel injection system might be helpful... it isn't an L-Jetronic, and it isn't very close to the old system used in R11 bikes.

1. Forget about Lentini zero-zero. It doesn't apply to the R1200 system. Trying to do this will not work.

2. The TPS is a learned response. The ECU learns it the first time the throttle is fully opened after the battery is disconnected. There is no need (and no use to) twisting the throttle three times and sacrificing a chicken. Even if you don't give it a full twist - the ECU will continue learning the TPS setting until it's certain it knows the full range of the throttle opening. It's not considered an adjustable part on the R1200 fuel injection. Most of the mixture setting is done by a fuel map with input from the O2 sensors and various engine sensors (temperature, knock, etc.) The output from the O2 sensors on the R1200 system (note there are now two of them) is used more then the old systems did, as a control factor in setting the mixture.

3. Idle can't be physically adjusted. It's stepper motor/ECU controlled. To change it would require reprogramming the ECU, and there is no idle adjustment setting on the ECU. It's 1,100 RPM and that's all it's going to be. The screws on the throttle bodies are NEVER EVER to be touched. EVER. If you do dingle with them be prepared to buy a new throttle body. These set the minimum closing angle of the throttle body. Too large and the steppers will have a difficult time in controlling the idle. Too small and the butterfly is likely to stick closed.

4. Fuel cutout is done by engine RPM. The ECU knows if the engine is decreasing speed or increasing speed. When decreasing speed, and under certain conditions - the ECU will cut the injectors. It should not be cutting the fuel under any engine steady-state RPM, or even low RPM with engine speed increasing.

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Doing a logical step by step tuning of the bike is likely to sort out this problem. This means a cold engine valve adjustment, done really carefully (I shoot for 0.001" accuracy and uniformity), then a check of the off-idle throttle body balance. And checking that both throttle cables have free-play when the throttle is closed. I have seen bikes worked on by professional mechanics that were done poorly. Getting them right makes a big difference.

There have also been cases of low speed roughness due to failed stick coils on the R12 engines. This bike seems too low mileage for this to be the case, but it shouldn't be discounted. To find a bad stick coil, with the engine idling, disconnect each coil from the engine harness - at the clipped connector on the coil. DO NOT remove the coil. DO NOT break the clip on the wiring harness. If you disconnect any one coil and the idle doesn't change (get rougher) - that's the bad coil. The other way to test them is replacement (what dealers usually do - at your expense.) This is more effective for coils that are failing under high-load (accelerating at high engine load conditions.) Unfortunately there are no stored codes for misfires on the Motronic ECU on the R12 engines (which is a shame since that will point to a bad coil very quickly - as it does on BMW cars.)

I'd also want to hook the bike up to a GS-911 and observe a few things, like the action of the O2 sensors. Watching what they do can reveal a bad O2 sensor (causes the system to fall back on a default fuel map instead of active adjustment) or - can show a chronically rich or lean condition (if one cylinder looks different then the other, but the sensor is still showing the normal switching interval.) The GS-911 will show the TPS readout, and on some models you can do a reset of the calibration using the GS-911. Again - some knowledge on what does what and how the system works will help figure out why something is, or isn't happening.

It might be interesting to hear from Joe Finn's friend who is doing fuel injection remapping.. I'm certain he'd have more to contribute to the conversation.

I'll correct one thing - I just saw Mike's bike has 60,000 miles on it. There is certainly the possibility of a failed stick coil at that mileage (it's why I'm running two replacement coils on my R12R at 62,000 miles.) The coil test outlined above might be somewhat revealing. Rough low-speed and off-idle running has been mentioned as a coil failure by some dealer tech's I've talked to. It's not entirely uncommon. The cylinder continues to fire, off the other coil/plug, but the engine runs roughly at small throttle openings.

[Invertedmike]

Hey Don. You are quite the "fountain of knowledge" with this bike. I'm now glad I have an issue I want to clean up because I'm getting an accelerated technical course with this thread. I really enjoy learning all the technical details of my engines. Usually takes years to acquire with prior bikes, not this time however. Thanks for taking the time to reply with so much useful information.


"Doing a logical step by step tuning of the bike is likely to sort out this problem. This means a cold engine valve adjustment, done really carefully (I shoot for 0.001" accuracy and uniformity), then a check of the off-idle throttle body balance. And checking that both throttle cables have free-play when the throttle is closed. I have seen bikes worked on by professional mechanics that were done poorly. Getting them right makes a big difference."

I am certainly planning to do an accurate valve clearance adjustment and TB balance with a Carbtune. Just one more reason why I like this engine, it's so much more maintenance friendly than my last engine. Valve checks on a V4 VFR800 were not fun.

"There have also been cases of low speed roughness due to failed stick coils on the R12 engines. This bike seems too low mileage for this to be the case, but it shouldn't be discounted. To find a bad stick coil, with the engine idling, disconnect each coil from the engine harness - at the clipped connector on the coil. DO NOT remove the coil. DO NOT break the clip on the wiring harness. If you disconnect any one coil and the idle doesn't change (get rougher) - that's the bad coil. The other way to test them is replacement (what dealers usually do - at your expense.) This is more effective for coils that are failing under high-load (accelerating at high engine load conditions.) Unfortunately there are no stored codes for misfires on the Motronic ECU on the R12 engines (which is a shame since that will point to a bad coil very quickly - as it does on BMW cars.)"

Very interesting troubleshooting consideration. David R mentioned maybe a bad stick coil in a previous post also. I will definately troubleshoot the coils once I get the maintenance manual delivered so I can familiarize myself some more with the proper system components. As you mentioned, I actually have 80,000km on this bike now and stick coil replacement is not in any of the service history paperwork I have from the previous owner...

"I'd also want to hook the bike up to a GS-911 and observe a few things, like the action of the O2 sensors. Watching what they do can reveal a bad O2 sensor (causes the system to fall back on a default fuel map instead of active adjustment) or - can show a chronically rich or lean condition (if one cylinder looks different then the other, but the sensor is still showing the normal switching interval.) The GS-911 will show the TPS readout, and on some models you can do a reset of the calibration using the GS-911. Again - some knowledge on what does what and how the system works will help figure out why something is, or isn't happening."

I now have a GS-911. Recording trends in the O2 sensors is a task I will perform to really learn how the engine is behaving and to develop a baseline for future comparisons of engine health.

"It might be interesting to hear from Joe Finn's friend who is doing fuel injection remapping.. I'm certain he'd have more to contribute to the conversation."

"I'll correct one thing - I just saw Mike's bike has 60,000 miles on it. There is certainly the possibility of a failed stick coil at that mileage (it's why I'm running two replacement coils on my R12R at 62,000 miles.) The coil test outlined above might be somewhat revealing. Rough low-speed and off-idle running has been mentioned as a coil failure by some dealer tech's I've talked to. It's not entirely uncommon. The cylinder continues to fire, off the other coil/plug, but the engine runs roughly at small throttle openings."

There could be light at the end of this tunnel...

[Nerdowell]

My new r1200r was so herky jerky it is a wander I got through the first day of riding. After 500 miles I have smoothed out considerable with practice.

Today I added the booster plug and it has smoothed the trottle response considerable.
The biggest change is the slow speed smoothness. I can now ride though a 20mph school zone without jerking. This will be a big help whenever I need to go slow on loose gravel.

[BLAIR1200R]

I can’t help but post to this thread, knowing all the while that I may not be adding value, but simply sharing thoughts…

I’ve had my R12R for just over a year, bought new, and have 8K on the bike. I commute almost every day to work and travel a combination of back roads, highway, and city during the commute.

Transitioning from a Honda CBR1000RR to the R12R, it raised my eyebrows when I first noticed this, so I searched the forum before I first posted my thoughts on this characteristic of my bike.

I too enjoyed the precision of my Honda and prided myself on smooth downshifts and silky runs up to a stop, applying just the right amount of front and rear brake to make the bike squat just so…

Maybe I’m a bit off, but I sort of embrace this now. In fact, sometimes it makes me smile as I chop the throttle on the R12R and bike nearly skips the rear wheel (exaggerating, but you know what I mean).. of course, have to be ready for it or it can crush your nuts.

These days, it’s just my BMW... it’s what it does and we like each other. I don’t consider my attitude a compromise, but a simple adjustment, because where it acts a bit strange in some areas, it absolutely dominates past bikes I’ve owned in many other ways.

Truly, if you don’t like it, get rid of it and buy another bike… hope you don’t, but either way, good discussion.

[MrPMS]

Beyond the O-ring solution, I find that my favorite accessory among the very many I've installed is the Throttle Meister. I keep mine always slightly "on" and it definitely makes low speed riding/shifting smoother. Still, I'm tempted by the Booster Plug...

[Mister Moo]

...Transitioning from a Honda ... it raised my eyebrows when I first noticed this, so I searched the forum before I first posted my thoughts on this characteristic of my bike. ...I sort of embrace this now.
These days, it’s just my BMW... it’s what it does and we like each other. I don’t consider my attitude a compromise, but a simple adjustment, because where it acts a bit strange in some areas, it absolutely dominates past bikes I’ve owned in many other ways...

My thoughts exactly coming off 20-years of GoldWings and old Brits. It never dawned on me to cure the characteristic. I figured it was what lumpy twins with FI do. I would prefer a perfect bike but haven't found one in 40-years.

I have been forced to practice. My first and last 1/2-mile each day are usually on my dirt/sand/gravel road. After the first slide-for-life into the tank I decided the bike was sometimes twitchy, obviously on gravel in 1st and 2nd gear, working in the 20-40kph range. Technique (ha - anticipation) cured half the problem and a little clutch-slipping in low speed transitions took the pucker-factor out unplanned decel in the gravel.

If there IS a cure I'd employ it.

[Mister Moo]

...An interesting observation I note about this throttle cut issue at low power is the fact that I have very little to no travel left... The moment I release some of the throttle from that speed, I am crossing the idle power threshold...

+1 Excellent observation.

[objectuser]

After reading this thread, I realized that my R seemed to have the same issue as that described by the OP.

I had also noticed that my GS didn't seem to have the same issue as the R (both 2009s).

I mentioned in another thread that I just got my bike back from its 12k mile service. When I took my bike in, I mentioned this issue to the service manager. I also mentioned another (perhaps related) issue: my bike was stalling if I started it cold and didn't add some throttle.

When I went to pick up my bike, I asked if they had been able to sort the small throttle application issue. He said (and I could have gotten this wrong ... I know next to nothing about this stuff ...), "syncing the throttle bodies usually takes care of that".

Well, whatever they did, it worked. The throttle response is much smoother at small throttle applications. The bike is much easier to control. And it no longer stalls after starting it cold.

[tinytrains]

Yes the compression braking of a big twin combined with drive-line lash can be quite jolting at low speeds. Especially if filtering through stopped traffic. Add bouncing over the lane markers and it is quite rough. I have learned to pull in the clutch and use the brakes when I need to snap the throttle shut. That takes the bite out of it and makes things more pleasant.

[Invertedmike]

Hi all;

Original poster here. Just wanted to make an update about this thread with the resolution to my problem.

To recap my issue. Bought a pre-owned 2008 r1200r. Love the machine but was not impressed with a characteristic this one had at low throttle/off throttle response at low speed. Specifically pronounced at 40kph and 2nd gear, easing off the throttle as lightly as possible resulted in a strong throttle closed reaction practically every time. Really distracted from the ride at low speeds.
I know about the Boxer traits, rode a couple others over the years before committing to purchase. This issue was different than the traditional Boxer quirks of big twin compression engine braking, etc.

Got the bike late last season, no time to put into taking it apart or service beyond winter prep. I wanted to ride in my spare time. Was going to wait until next spring to tackle the issue. In the meantime I have learned lots.

First step was to baseline the engine with valve adjustment and TB sync. Did this today. Valve adjustment after much research and notes went very well. Took two hours but I was taking my time. The top valves of both intake and exhaust on both sides were a bit looser than the bottoms but not too off. After careful repeated adjustments I was very happy with the result. Went for the test ride and warm up for TB sync. Not much difference in the performance but I suspected that. The true test was the TB sync.

Returned to my garage, setup the only synchronizer I had for now, the Carbtune product. Hooked up the center two lines and completed the procedure with much adjustment required. Bottomed out the right adjuster, and had to work with the left side adjuster the most.
Before sync, a significant difference in the vacuum pressure, like just over double difference at 4000rpm. After the adjustments, very close together at 3000 and 4000rpm. I wish I could post images to highlight the Before and After.

Final test ride. Bingo. The rough throttle cut experience was virtually eliminated. My throttle closing response at low speed/power is much better. Not Honda smooth of course, but I no longer unexpectedly get rammed into the fuel tank at times. The idle is actually a lot smoother now also. My handle bars don't shake as much anymore which surprises me because I thought TB sync procedure only adjusts off idle balance and the steppers handle the idle?

Anyway I'm very pleased. I will eventually get hold of a more accurate differential style meter like a Twinmax and really sweeten the TB sync but for now a full order of magnitude better.

Thanks to all that gave suggestions.

Cheers;

Mike

[rad]

I too enjoyed the precision of my Honda and prided myself on smooth downshifts and silky runs up to a stop, applying just the right amount of front and rear brake to make the bike squat just so….

Honda/BMW

My last Honda, 05' 800VFR, was almost impossible to ride at a steady speed below 30mph. It was a common issue on the VFR forum, and we had a few fixes. It was a far cry from my silky smooth 94' 750VFR.

Every big BMW twin I have owned has not been completely thrilled with low speed fueling; I've owned 6 of them. My 07' R1200R is not too bad, it could be better but it is not really an issue. My 04'R1100S I just sold was best of the lot, pretty good at low speed.

My experience with my 05’VFR showed me that most riders on the forums have been riding long enough to know proper low speed motorcycle performance. There were many on the VFR forum who’s bikes were smooth and they just thought and posted that it must be “us”, not our bikes, with the low speed problems. I sorted mine out with an O2 sensor bypass with a couple of resistors.

The OP should not give, or be dissuaded by those that discount his experiences. Take a systematic approach and rule out every possible option, starting from simple/cheap, moving on to complicated or more expensive.