Fuel Injection FAQ

Started by Adam #1001, compiled & edited by Kristian #562
Please read the Disclaimer before attempting any work in this FAQ.
Last Updated: 4 April 2007, by Winter #1935

• Introduction
• Section 1: History and Development
  • Names
  • History of other units
  • The BMS-C
  • The BMS-C II
• Section 2: Blood and Guts (Internals)
  • Sensors
  • Inductive Sensor (RPM)
  • Air Temperature / Air Flow Sensor
  • Coolant Temperature Sensor
  • Air Pressure Sensor
  • Lambda Sensor (O2 / Oxygen)
  • Throttle Position Sensor
  • Starter Button
  • Controls
  • Ignition Coil?
  • Cooling Fan
  • Throttle Valve Actuator
  • Coolant Indicator Lamp
  • Speedometer
  • Fuel Injector and Pump
  • BMS-C Unit Images
  • BMS-C II Unit Images
  • Connectors
  • Diagnostic Plug and BMS-C Connector
  • JTAG Port
  • What About the BMS-C II?
  • Software Versions
  • General Comments
  • BMS-C Software Versions
  • BMS-C II Software Versions
  • FI Maps
  • Custom Software Upload
• Section 3: Misc
  • Resetting the BMS-C
  • Method 1: Removing the BMS-C connector (easy-ish)
  • Method 2: Disconnecting the battery (annoying)
  • Method 3: Removing the fuse (easy)
  • Why do I need to wait 15mins?
  • Has anyone experienced any problems with the suggested reset methods?
  • Should I let the bike idle after a reset?
  • Idle Speed
  • Is it easy to adjust and can someone tell where to adjust it?
  • Can the Fuel Nanny adjust the idle speed?
  • How do I fix a fast idle then?
  • Any other methods to adjust the idle speed?
  • Poor idle and throttle response from your GS?
  • What is the idle speed for fuel injected F650s?
  • Fuel (Types and Running Out)
  • Should I use Premium or Regular fuel?
  • Octane Ratings
  • What about MTBE in the GAS? What about Ethanol?
  • What about Injector Cleaners?
  • What happens if I run out of Fuel with an FI bike?
  • Can I use OPAL fuel?
  • FI Links
  • Throttle Body
  • How do I remove the injector?
  • Cleaning the throttle body
  • Two springs on the throttle body?
  • General Questions
  • Do I need an FI adjustment or Reset for High Altitude?
  • Is the BMS-C a "learning" fuel injection unit?
  • Do the F650 Fuel Injected models have an anti-knock sensor?
  • Strange Tach (RPM) behaviour?
  • Strange Tach (RPM) behaviour - buzzing?
  • FI bike keeps stalling?
  • How can I retrieve the fault codes / error codes?
  • Does anyone offer an alternative to the MoDiTeC?
  • How long does it take to update the software on a BMS-C?
  • Will my bike start if the battery is flat?
  • Tach needle does not return to 0rpm?
  • Does the BMW self correct for fuel mixtures like a vehicle does using the O2 sensor?
  • 3 Identical 2-pin Connectors: Which goes where?
  • Potential Causes of FI Problems?
  • Difference between old and new Fuel Injector?

For other relevant FAQs:

• Surging and Stalling FAQ
• GS Fuel Tank FAQ
• Fuel Pressure FAQ
• Fuel Nanny FAQ
• Hard Starting / Poor Running FAQ
• GS Hard Starting / Poor Running FAQ
• BMW Technical Service Bulletins

When BMW released the newer GS / Dakar / CS models of the F650 in 2000, it came with Fuel Injection. Some considered this to be a step forwards, and some a step backwards. This FAQ goes into detail on the Fuel Injection unit. FI controls the fuel/air mixture very accurately (emission control), is compact (design), and deals well with big single-cylindered engines where air can flow too slowly for efficient carburetion (performance). Given BMWs fondness for electronic engine management systems, the fact that FI integrates easily here makes it an obvious choice. The ECU provides mechanics with a superb diagnostic tool, and engine mapping software can be upgraded easily (and thereby hangs a tale).

Note: It is perfectly normal for your revs to remain higher than idle speed (i.e. 1800-2000rpm) as you come to a halt with the clutch in. This may have been one of the things BMW did to help prevent Surging and Stalling problems. One theory is the wet clutch in the F650 bikes results in clutch drag - keeping the revs higher until you have completely stopped. Once you have stopped the revs should drop down to 1500rpm.

The Fuel Injection unit has had many names over the years. This is due in part to confusion over comparisons to other BMW related FI systems. The following list is by no means a conclusive list of the names, but should explain at least where some of the confusion comes from:

Other names are often confused with the FI system, include MoDiTec (a device used by BMW to talk to the BMS-C). Within this document, the FI system on the F650 bikes has been refered to as the BMS-C unless otherwise noted. This is also consistent with the BMS-K used on other BMW motorcycles.

According to BMW brochures: the new BMS-C II engine control system, with its quintuple calculation speed, considerably reduces fuel consumption and exhaust emissions. At high speeds this makes quite a difference. Cruising at 75 mph the reduction compared to the predecessor amounts to 0.7L to 4.3L per hundred kilometers. And the torque curve has been optimised into the bargain while meeting EU-2 emissions standard with ease.

This section contains the real blood and guts of the BMS-C - what we can work out anyway! Most of this information is available through various sources already on the Internet. The rest has been worked out by simple deduction. The image on the right has been modified. The original image BMW used in a service bulletin was inaccurate (in two ways: Firstly it was used in the context of a dual spark bike, and secondly the BMS-C was referenced as a BMS-K).

You can see the Blue lines are the things the BMS-C controls, and the Red lines are the sensors providing input to the BMS-C. Note: The red temperature light is shown in the middle right of this image. Some inputs appear to be missing (starter button).

You might want to check out the GS Documentation FAQ for more information on the wiring diagrams of the single spark fuel injected bikes.

The sensors provide input to the BMS-C. Values from each sensor are sampled at a certain rate (unknown) and fed into various calculation. These calculations determin the amount of fuel injected and various other things.

Inductive Sensor (RPM)

According to the Moto One Performance Notebook page for the F650 GS-Dakar-CS, the RPM sensor is a single pickup sensor on the flywheel. This sensor apparently is used to detect engine rotation speed (i.e. RPM) and cycle position. The cycle position is apparently established by the fact the engine slows down as it comes up to TDC on compression, and accelerates away from TDC on firing.

Air Temperature / Air Flow Sensor

This sensor is located in the "snorkle", airbox or whatever you want to call it. On the GS/Dakar, you can find it by removing the RHS faux tank. Check the Air Filter Location FAQ for the Air Temperature Sensor. Note: At this point in time it is unclear if this sensor is for air temperature or airflow.

Coolant Temperature Sensor

Engine temperature is based on the coolant temperature sensor. This sensor can be found on the RHS of the engine, just near the coolant bleed valve. This sensor has 4 pins, however only two pins are used. This sensor connects to the BMS-C unit. The BMS-C unit then controls the Fan and temperature idiot light. Note: Because the engine temperature is based on coolant temperature, rapid changes in oil temperature will not be detected. See the Coolant Change FAQ for more information.

Air Pressure Sensor

There are no pins on the BMS-C connector to the Air Pressure Sensor. This sensor is found on the BMS-C mainboard itself. This is the Motorola MPX4115A Manifold Absolute Pressure Sensor. According to Haakon's information and the datasheet:

Troubleshooting: Because this sensor is built into the BMS-C itself, there is no easy way to test it. The only method that can be suggested is to swap the BMS-C with another similar model. You could open the BMS-C itself, and using a voltmeter check the resistance on certain pins and compare to the MPX4115A datasheet.

Lambda (O2 / Oxygen)

Located in the exhaust header pipe, this sensor is used to detect the oxygen levels in the exhaust.

Throttle Position

The TPS (Throttle Position Sensor as it is sometimes called) is located on the throttle body. It detects the position of the throttle, and hence is probably the most direct input a rider has to the BMS-C.

Starter Button

The starter button is a very simple on / off sensor.

Ignition Coil?

It is unclear if this is a control or sensor. Given there is already the Inductive sensor (RPM), this is more likely used to start the engine.

Cooling Fan

The BMS-C will emit a signal on this pin when the coolant temperature sensor reaches 102°C (225°F). Please see the Overheating FAQ.

Throttle Valve Actuator

You know that thing that sounds like an aerial going up / down when you turn the ignition on / off (or switch the kill switch to the enable / disable position)? That is the throttle valve actuator. Note: It is not recommended to switch the bike on/off or flick the kill switch on/off rapidly, as this could result in problems for this "control".

Coolant Indicator Lamp

Also known as the temperature idiot light, the BMS-C will turn this light from off to on if the coolant temperature rises above 118°C (245°F). See the Overheating FAQ for more information.

Speedometer?

Fuel Injector and Pump

The fuel injector is always (when the ignition is turned on) connected to +. What opens it is when it is earthed by the ECU. The Techlusion box prolongs the earth time.

The following images are from Robert's Page and are of the BMS-C:

Diagnostic Plug and BMS-C Connector

There are several connectors associated directly with the BMS-C. The first and most obvious is the round 10-pin diagnostic plug. The second and fairly obvious connector is the that from the main wiring spool to the BMS-C itself. The following tables are based on information from Robert's Page. BMS.pdf

Table 1: Diagnostic connector pin-outs

Table 2: BMS-C connector pin-outs

JTAG Port

There is a third and lessor known connector on the BMS-C mainboard itself. If you take a look on the top right of the image of the mainboard, you can see a small set of solder points (two rows of five silver lines). These connect to the JTAG port on the CPU. What do they do? The JTAG connector allows you to connect a computer directly into the CPU and manipulate what is going on. It even allows you to change the contents of things like flash memory. These connectors are installed on most modern electronics devices, allowing easier design and programming.

What About The BMS-C II?

There is currently no information on the connectors for the BMS-C II. The diagnostic connector is the same. However due to the second spark plug, the BMS-C II Connector has not yet been written about. It is also unknown if the BMS-C II has a diagnostic JTAG port. Given the JTAG port on the earlier model BMS-C, it is fairly safe to assume the BMS-C II has a JTAG port.

General Comments

When you look at the internal code for the BMS-C, it appears to be written by two different programmers (or groups of programmers). The first part appears to be using the standard programming techniques for the CPU used in the BMS-C. The second part uses a completely different set of techniques. This is probably consistent with Hella creating a set of "system" libraries for using the BMS-C, and BMW creating the main code. There are only small changes to the internal code in each software versions. This is consistent with observations made.

BMS-C Software Versions

(Source: http://f650gs.da.ru/)

The following table has been shamelessly taken from the robertosat website:

BMS-C II Software Versions

• Version 170: The earliest known version
• Version 180: Program release 170 was identified as a potential cause of poor starting (when cold), engine shuts off and poor engine response when the clutch is engaged after selecting a gear. Version 180 was released 4 June 2004. See BMW Service Bulletin from May 2004 (13-003-03-(051)). Please Note: The actual BMW service bulletin picture is incorrect. The caption states "Reprogram BMS-C2 module using GT1 program release 180". However the image itself shows a BMS-K (incorrect) and also appears to show a single spark engine (incorrect).
• Version 200E: Released approx. September 2006. Apparently improves throttle response. It also appears to improve more cold starting problems when a new decompression lever (part no 11 31 7 699 386) and spring (part no 11 31 2 343 097) are installed - see Parts Fiches. See BMW Service Bulletin from September 2006 (00-020-06-(058)). Although some bikes already have the new decompression lever installed.

The following FI maps have been extracted from various software versions. The offsets of these maps change from version to version. Please note: The original FI maps from the robertosat website are not entirely correct - they are based on linear index values (100, 200, 300 ...), however the index values used in the FI software are not linear. The FI maps shown below have the correct representation.

Robert B., Austria, edited by Kristian #562, 27/11/01

There are three methods you could use to upload new software to your BMS-C:

1. Use the instructions below to remove the EEPROM chip and either have it reprogrammed, or reprogram it yourself if you know what you are doing.
2. Use a MoDiTeC or Group Tester 1 (GT1) - these special computers communicate through your diagnostic plug, and are very expensive "special" BMW computers.
3. Use the JTAG port on the mainboard - no one has done this yet, so if you have the knowledge and you do have success, please let us know the details.

Reprogramming the EEPROM
In early 2000 the bikes that were shipped in Europe had a built-in software that gave the F650GS more noticeable torque and there was absolutely no surging or backfiring. The only problem was sometimes the bike stalled. The rest of the story is written in other FAQs on Surging and Stalling. As I was very unhappy about the surging I decided to try and upload the old software back again. As I was not able to communicate through a serial connection with the HELLA Motronic, I had to remove the EEPROM. To do this you have to unplug and open the box housing the EPROM.
Here is a Photo of the EEPROM. When removing the main board you have to take into consideration that the plug is fixed to the metallic casing with some glue. That glue has to be softened by heat, but not in direct contact, e.g. a hair dryer. In addition there is a metallic grounding connection which has to be cut. Both can be seen on the attached figure.
Here is a photo of the what you should cut
The metallic grounding is connected to the (pin marked green) on the plug and the attachment is located under the plug (position is indicated by blue arrow). That connector is nearly inflexible and the other end is mounted to the metallic housing. You have to have a very special tool to remove it. As we did not have that tool we had to cut it. As a replacement for the connector we soldered a cable (red arrow) onto the pin.
Then we soldered out the EEPROM and read the current software using the equipment of a chip tuning company. That software was version 9.2. As no one had any idea how to remap the existing software, we decided to downgrade to the old European software.
You can get a copy of the software at http://www.obd-tuning.at/. This company has a lot of experience in doing this. I believe http://www.bbpower.de has also got a copy of the old software. The review of the old European software was made with MISTERED by Hansen at http://www.freemred.de/main.htm. Every software version is 512 k bytes and is not encrypted. MISTERED is software which can read the contents of the EEPROM and you can even modify it. In addition it is possible to make a graphic overview of the FI mapping. First you read the EEPROM's contents into a PC. You then have a 512 k byte file on your PC. In addition to the standard abilities of MISTERED to modify the file, MISTERED can also make a graphic interpretation as shown above. This Graphic Image of the mapping is very helpful in identifying the various parts of the file as it consists of a program and the "Kennfelder". "Kennfelder" is the mapping table which is tells the program how rich the fuel/air mixture has to be for various conditions. Now my F650GS is running with the old software in combination with the new injector #0280155788. I have full power/torque across the whole rpm range, reduced vibrations and no surging even down to 2000 RPM. The only disadvantage is a higher fuel consumption of about 25 percent. Initially the stalling reappeared but after about 500 miles of driving the frequency of it decreased dramatically. I can now say I have a perfect running bike and would recommend anyone still plagued by surging and stalling to go the same way. There is no reason why this approach should not work on bikes in the USA or the UK. http://www.obd-2.com/routepit.htm Returning back to the original software. What you need is a special soldering-kit, a special forceps, an EEPROM reader/writer and a PC. You can find the EEPROM Part No at http://www.geocities.com/robertosat/. So a specialist can tell you which size of forceps and so on is needed. You cannot download the software on the net but you can ask Haakon in Norway for it. Some weeks ago he posted that he is willing to do it. IMHO it would be safer to send the DME to http://www.obd-tuning.at/. Mr. Baumgartner has a lot of experience in doing it and he is a very careful working man. The last time the whole procedure took him about 15 minutes. To me it would take about 2 hours and I am not sure if it would work afterwards. You can also ask Mr. Baumgartner if he is willing to send you the programmed EEPROM. Robert. No question, if I couldn't have managed to get the old European software I would have bought that Fuel Nanny at that time. But with my present knowledge I wouldn't buy that FN. So please have a look on the net for power boxes. There are a lot. Maybe the most famous is one is the POWER COMMANDER . When you read the reports about it you will see that it is very costly to tune an engine. And it is much more difficult than it is described at Techlusion's site. Besides there is always the possibility that you destroy the engine with wrong settings. In addition it is the statement of many real experts that the brown curve on the DynoJet run at Techlusion must be a fake. So it is my advice that you get the 5001. That 5001 was designed by BMW for a perfect open-loop running engine.

"When folks have stalling, surging or uneven running problems and a sensor is not working correctly or the idle valve sticks, the software uses a substitute value setting and the fault is recorded in the BMS Compact unit. Disconnecting the battery for a few minutes (Removing JUST the negative terminal (for a while) is all you need to do if you want to clear the "brain") deletes those recorded faults and resets the unit to its factory setting. That is all that is required for a reset. No twiddling throttles, no running engine till fan comes on. If it keeps happening then the owner should take the bike to the dealer and let the BMW MoDiTeC establish what the problem is." Trevor #999's BMW Contact... See the Battery FAQ on how to get access to / disconnect the battery.

Method 1: Removing the BMS-C connector (easy-ish)

1. Turn your key / ignition switch to the OFF position first!
2. Remove the seat from your bike
3. Undo the large multi-pin connector off the BMS-C itself.
4. Wait 15 minutes, then reconnect the BMS-C
5. Note: If you are staying somewhere and you do not want anyone to ride your bike away, you can even take the whole BMS-C unit with you!

Method 2: Disconnecting the battery (annoying)

1. This OUTDATED procedure has been used with some success in the past but according to Trevor#999 Contact at BMW, it is actually incorrect.
2. Remove the faux tank plastic to get to the battery
3. Leave the battery installed, just disconnect the negative terminal 100% for 2-3 minutes. Note the clock will re-set to 12:00.
4. Pretend your bike has just gotten a FI software upgrade and the battery is disconnected.
5. Re-connect the battery positive 1st, put the plastic side panels on and roll the bike outside to fresh air.
6. Key on ignition to dash lights "on" position (DON'T START!).
7. Fully twist throttle 2 times hitting the min and max levels, release throttle completely. (This part of the procedure is contentious. ed)
8. Start bike with NO THROTTLE, leave bike alone (don't touch throttle) idling for 5-10 minutes until the fan comes on. (Again a contentious issue)
9. You are done. Ride away or shut down bike.

Method 3: Removing the fuse (easy)

1. The other "simple" method I would suggest is removal of the fuses. Can not remember which fuses, but the 15A and 10A fuses ring a bell (remove both fuses just to be sure). The manual only warns you to switch off the ignition before changing fuses and never to repair a fuse.
2. Once the fuse has been removed, wait 15mins then plug it back in
3. Note: This method has not yet been confirmed. However if the ECU does get power even with ALL the fuses removed, I would be somewhat concerned, as this could result in damage to the ECU if there was a short circuit somewhere.

Why do I need to wait 15mins?

• The BMS-C uses a CPU that contains about 1-4 kbytes of memory. This memory probably retains power for short periods of time through a capacitor on the BMS-C mainboard. It probably takes ten minutes for this capacitor to discharge. Once the capacitor has discharged, the contents of the CPU memory are "lost" - thus any "stored" information is lost.

Has anyone experienced any problems with the suggested reset methods?

• I have yet to hear of a fried / damaged BMS-C caused by any reset method suggested. The only damage I have heard about has been caused by people connecting a battery with the wrong polarity. See the Battery FAQ Winter #1935
• I have now lost count of how many times I have disconnected and reconnected my BMS connector. When I am on trips, IF I think the security of my machine is doubtful, I take the BMS out and put it on my Motel room each night. My bike is now 4 years old and no problems so far. jack #1977
• There is a remote chance of damage to the BMS-C if you connect the battery terminals up in the wrong order. When re-connecting the battery, the ground (negative) terminal is connected last. Winter #1935

Should I let the bike idle after a reset?

• BMW manuals do not recommend allowing the fuel injected F650's idle for too long.
• I believe that letting the bike warm up a few minutes (don't touch the throttle) when you crank it up for the first time in a new loction is a good thing to do. I don't have the science to support any of this. it just seems to work. andy112652 #1481
• I agree that letting the bike run is beneficial. This is contrary to what the manual advises (which is to get underway immediately once the bike is started). I think allowing the bike to idle helps establish the base parameter of the computer's air-gas analytic function. I notice my bike stalls a lot less when I let it idle for a while. NothingClever #1441
• Note: The cooling system on the fuel injected F650's is not that fantastic. Allowing your bike to idle for too long will result in the fan coming on, and eventually may result in your bike overheating.

I have just purchased an '00 F650GS, but it seems to idle around 1500 to 1600 rpm. Is it easy to adjust and can someone tell where to adjust it?

• The idle speed is controlled by the electronics in the chip within the silver aluminium box under the seat. It responds to signals from various sensors on the bike, to set the *correct* idle speed. There's no way you or I, or even your friendly mechanic, can change that. Trevor #999
• The correct answer is no, you can not adjust the idle to a lower speed. Design speed is 1400-1500 rpm. Your Tach is not a lab instrument so it my not be totally accurate. Idle speed is set by BMS adding idle air through an electrically operated port. Not the butterfly. Idle speed is high because at speeds of under 1400 the AUTOMATIC compression release comes into play and the bike is likely to stall. Take a classic F650 and turn the idle down and listen to what occurs and you will understand. Supertech.

Can the Fuel Nanny adjust the idle speed?

• With the Techlusion Fuel Nanny you can change idle speed as well as other variables such as fuel delivery. FI is NOT perfect and bike conditions change over time. Having an owner adjustability of fuel delivery is appropriate and worthwhile - which is why I ride with the Fuel Nanny. I tested with CO2 and Dyno to find where the idle was off and now have the bike dialled in across the full range of operations. IMO the Fuel Nanny really helps in this aspect (and others) of the bike because with the closed to mods BMW FI system you can't do something simple like an idle mixture screw. DHP#711. (Don't go too low, however, due to the Compression release. Ed)

How do I fix a fast idle then?

• Maybe try the FI reset trick. (See Resetting the BMS-C) Ignition key on, but don't start the engine. Take the throttle to the stop and back to fully closed three times. Then hit the starter with no throttle. The fast idle might be because the FI ECU is in error about the idle throttle position at idle. The bike does not have an idle like a carbed bike where it runs on an open airway. Andy #982.

Any other methods to adjust the idle speed?

• There is a grub screw on the throttle body. I thought it was just a stop but had a play resulting in varying idle speeds. db. THIS IS NOT CONFIRMED and NOT ADVISABLE.

Poor Idle and throttle response from your GS?

• Try cleaning the throttle body

What is the Idle speed for the fuel injected F650?

• For single spark FI F650's, it should be 1500rpm. If your idle speed is lower (1400rpm or 1300rpm), it is likely you have an older version of the fuel injection software - talk to your local dealer to see about getting your software updated.
• For dual spark FI F650's, it should also be 1500rpm, however some people have noted it can sometimes idle at 1400rpm. If you see the revs going lower than this, listen to the engine - if the sound of the engine is changing, you have a big problem. If the engine sounds normal, then you are experiencing a known problem with the FI F650. The best way to kill the engine, wait ten seconds, then restart the bike - the tach should show the correct engine speed.

Should I use Premium or Regular fuel?

• Note: This is a very topical debate
• If you have a look at the tables above you will see there are some octane ratings specified for specific versions of software installed on the BMS-C. Thus if your bike has a "premium" fuel map installed, you should probably run "premium" fuel in your bike... (It is unknown if the BMS-C II - used in the dual spark FI models - have different fuel maps for different fuel grades).
• As a general rule of thumb - use the lowest grade of fuel you can without experiencing "knocking". The fuel injected F650 bikes do not have a "knock" sensor, and thus will not adjust the FI system if knocking is detected. (Note: This rule of thumb is also debatable). Knocking is very bad for your engine.
• If you feel using premium fuel is better for your bike, then use it. It is your money afterall.
• Knowing BMW, you may void your warranty if you use a grade of fuel lower than recommended.

Octane Ratings

by Marty #436-Chicago-97 F650F, Flash#412 & Sojourner

There are 3 standards to grade fuel: RON, which is the original standard. MON which is a more recent standard and PON, which is a blend of the two (and used in the US). The conversions between the different standards are not always straight forward, but generally"

95 RON ~ 91 PON (as used in the US)
85 MON ~ 88.5 PON

So, next time check what the fuel pump says (RON, MON or PON). Sojourner

• RON=Research Octane Number
• MON=Motor Octane Number.
• PON is Pump Octane Number which is obtained by the average: (RON + MON)/2

There is NO reason to use gasoline with octane any higher than what it takes to keep your engine from pinging. Expensive gas does NOT make more power. The higher the octane, the slower the gas burns (to prevent detonation). High compression engines are prone to pre-ignition. High octane prevents this phenomenon.

You might as well burn a paper sack of dollar bills in the driveway before you leave home and see if your vehicle runs any different as to fill it with $4/gallon gasoline (unless it has extremely high compression). They will both have exactly the same effect.

For a CAR with an 8:1 compression ratio, this number is at normal atmospheric pressure. Depending on the boost pressure, yes, 91-or-higher octane as per advisory may be required. That is the reason lots of turbo engines have knock detectors linked to water injection systems.

• Some high performance cars, including all modern cars with turbos (I believe) have knock sensors that retard the ignition when the engine knocks. Since using premium gas will allow the ignition to be advanced, more power will be produced by the engine when using premium gas than when using lower octane fuel. In this design, premium actually gets you more power, but that is not true of lower-tech engines. Richard #230
• So placing 100 octane gas into said car does nothing for performance? It just makes for a smoother, slower burn and eliminates pre-combustion (knocks)? In a turbo WRX "Pie Warmer," the higher the octane, the MORE power you should get for the reasons that Richard said wrt detonation and ignition timing. In a naturally aspirated engine, buying any octane rating more than the absolute minimum required to keep it from making funny noises is wasted money. In a naturally aspirated engine without fancy computer altered timing and/or detonation detectors, buying any octane rating more than the absolute minimum required to keep it from making funny noises is wasted money. Flash#412

What about MTBE in the GAS? What about Ethanol?

• The 76 station I filled up at advertised no MTBE in their gas now (maybe outside CA this makes no sense, I don't know). Anyway, since the weather in the bay area was so great last night it took me an extra 20 miles to get home. In that run, not a single surge fit. Zero, nada. I even _tried_ to make it surge by riding it like I do my other three bikes but no dice, it just ran smooth at any RPM, pulled surge free from 2500-5500 RPM and would cruise at 4000 RPM in 4th without any hiccups. Unless my bike suddenly healed itself when it turned over 4500 miles, it's got to be the gas. Could the MTBE additive be causing us problems? Kelly #1005
• That makes sense, as the MTBE just replaces the real gasoline and causes the fuel to burn lean. It also lets the refinery charge for a product that they used to have to burn off, because there was no commercial use for it. This way you get to pay more for your gas with this stuff in it, you get worse mileage, your bike runs lean and surges and it pollutes ground water. I just love it when big business and government regulators get together and work out a plan for helping the public. Richard #230, Pacifica
• An interesting observation! On both the test ride and my ride home I was waiting for surging like a condemned man waits for the hangman to pull the trap door... but I didn't experience any of this. I ran a *lot* between 4000 and 5000 RPM, 'looking' for a surge. Maybe the dealer fills their bikes with MTBE-free gas? I'll know if I start getting a surge when I fill my bike up for the first time. The good news (I think) is that they're getting rid of MTBE (if I remember my CA politics correctly). The bad news is that we'll have to see if Ethanol has any ill effects on our bikes. Seacuke
• I don't know about you guys, but my bike runs noticeably worse where the pump says "Contains 10% ethanol". So much so that I go out of my way to gas up at the only pump I can find in town that does not display the sticker. I will use the ethanol product if absolutely running on fumes, but the next 200 miles are jerky. Sean-STL
• I have a classic F so no surging problems :) but my other vehicle is a 99 Subaru which is very finicky on fuel. Here in Canada, I find I get the best mileage and power out of PetroCanada gas which does not have the ethanol/MTBE, however when it switches to winter gas it does and then I run Esso which is a little inconsistent, but better than the alternatives. I always have problems with Shell! Fuels which contain MTBE cause the car to have no power until it hits 3 grand at which point I get 'surging' which is really just a transition from no power to what it should be. I have learned to live with this by selective gas purchases but I have to say this would not be something I'd be happy about with my bike as it has a shorter range and you are forced to buy whatever is available at times. That and the only explanation I can think of as to why these fuels are messing up our vehicles, is a link to the O2 sensor and the exhaust makeup when burning these fuels... RacerRoo
• I just rode across USA and ethanol states gave poorer fuel mileage by far! I got 20 percent better without ethanol fuel. Randy748/Calif.
• For the last 18,000miles I've used 85 or 87 octane with no bad results--the bike (1999 F650)runs just fine on this. Bill No. 391 Las Vegas

What about Injector Cleaners?

• Seafoam - available at your local NAPA auto parts dealer (at least at mine) Fuel injector cleaners - designed to burn at hotter combustion temperatures, "burning off" the injector deposits. Some years of GM truck engines had injector "issues". Heard that some dealers had a "wrap around" heater that they slipped over malfunctioning injectors to "solve" the problem temporarily, don't know the details. How frequently can you put the engine on "self-cleaning cycle" until you start to see bad things happen? Techron is indeed an excellent fuel additive (all around). But all the oil companies put SOME type of additive in the fuel. All work differently on different types of deposits. Best strategy is probably to buy different brands/octane's of gas to use all of the "built in" additives. Personal experience: FI cars/bikes - use it maybe once per year (6-10 K miles). Carbs - only when issues (sticking float needles, etc) arise. YMMV. Marty #436
• If my suspicions are correct about the plastic construction of our fuel tanks, the [Berrymans] B-12 might eat it up. Why do you feel the need to clean the injector? The fuel filter upstream should theoretically catch anything large enough to clog the injector. As for combustion deposits? I may just have to pull mine out and take a look at it. But not until off season. Jetdoc, #1546
• You could also carry a small bottle of Marvel Mystery oil around to add when you gas up. Supposed to clean combustion deposits, lube pump mechanisms and injectors. Can't hurt if you mix in the correct amount. Yes, I'm a big fan of this stuff. It works really well at freeing up coked turbocharger bearings among other attributes. Jetdoc, #1546

What happens if I run out of Fuel with an FI bike?

• I have an 01 F650 Dakar and was curious to know what will happen if I run it out of fuel. I know first response will be don't, so let me say I don't plan to but it is not uncommon in outback Australia to have 400 or 500+ kms between drinks. On top of that conditions can vary dramatically (especially with a bit of rain) and fuel consumption can change accordingly. Specifically I am interested to know whether the fuel system will re-pressurize without intervention or will it need to be bled etc?
• If it goes dry, turn the ignition off so the pump doesn't run on. Once you replenish fuel and the pump pickup is re-submerged it should self-prime and run fine, though re-cranking may be extended before it fires, as there will be air in the supply lines that will have to purge out during a few cycles of the injectors. GSMullins, Advrider.

Can I use OPAL fuel?

• Background: OPAL fuel is supplied in some remote locations in Australia. It is considered to be unleaded 91 octane, but is designed to have much lower areomatics than traditional unleaded fuel (to reduce petrol sniffing problems in remote communities). Take a look at the BP website if you want more info including fact sheets:
  http://www.bp.com/sectiongenericarticle.do?categoryId=9008933&contentId=7016884
• Since you will not be using this fuel as a long term solution, I would simply add a small amount of upper cylinder lubricant to each tankful and ride. Dropping the heat range of your spark plug by one number (NGK, increase number value, for colder plug) will help reduce any pre-ignition problems,when riding under hot conditions. The slightly colder plug will not foul, under your intended riding conditions. jack #1977
• Hmmm... there is a small bit of lead in OPAL (50mg/L max). Does this mean I will have to get rid of the cat converter? - Yes Winter #1935

• http://www.geocities.com/robertosat
• http://www.motorcycleworld.com/motorcycles/technical/fuel_inject_works.cfm
• http://www.woodbridgedynotech.com/dynotuning/letalktec.htm
• For a build it yourself FI system (not for the F650!): http://www.bgsoflex.com/megasquirt.html

How do I remove the injector?

1. Let your bike sit overnight without running it (this should allow the pressure in the fuel line from the fuel pump to the injector to bleed down. However always assume that the line is pressurized when removing the injector, i.e.; wear eye and hand protection)
2. You are doing this outside with a fire extinguisher nearby arent you? The regulated fuel pressure to the fuel injector on the F650 GS is 3.5 Bar (50.75 pounds per square inch). The fuel pump is capable of developing a pressure much higher than that. The fuel system remains under HIGH pressure at all times, even with the ignition off and the bike left unused for many days. Wear safety goggles and protective clothing at all times when working on it. Hoses under pressure can slip off, spray fuel, and fling hose clamps off their ends at velocities approaching that of a speeding bullet without any warning. Flying hose clamps can create sparks and ignite the fuel spray when they hit a solid object. Ill repeat: work outside in a well ventilated area with a fire extinguisher handy.
3. Remove the side panels and faux-tank from the front end. See the GS Frame Fairing FAQ for how to do this.
4. Carefully remove the clip from the injector ((you have to reuse the clip) and the fuel line leading to it (CAUTION! keep your face away from the immediate vicinity in case there is still pressure in the line). The injector looks like the long one in this photo.
5. Gently Pull out the injector.
6. Fit new one. See custom fixes for Surging and Stalling or use a later BMW part.
7. Replace bits and bobs. Pay attention to the fuel lines, they may leak and barbecued prairie oysters are not nice if theyre your oysters.

Cleaning the Throttle Body

1. A few weeks back I decided to replace all the fuel lines and the intake manifold on my GS. I figured they were nearing their potential use by date and I did not want a failure, while on the road etc. So.....I replaced all the parts and while I was at it, discovered that after 60,000km, my throttle body looked a bit grungy.
2. airbox side and injector side
3. So I took to it with my CRC Carby Clean in a spray can, and gave it a good workover. In particular I made sure I cleaned the Idle Valve air passages, which were also dirty. This Idle valve, is the stepper motor unit (see top left, of second pic) that controls the idle speed, via metering the air to the intake, when the butterfly is closed. Its also the thing that makes that funny subdued cement mixer noise, when you turn the ignition on and off.
4. When I refitted the TB, I filled the injector line with CRC cleaner too, so it would flush the injector, on first start up. Since I have done this TB clean up, my bike starts better, idles smoother and picks up more smoothly from lower engine revs, when riding. It has also reduced chain snatch, when riding a little too slow in a higher gear. jack #1977

Two Springs on the Throttle Body?

• I found that there are actually two springs there, one on the outside of the other but both working. You need to get up close to see them both. jasonveale
• I don't know how mine is set up without looking, but I'd imagine there are 2 springs there in case 1 breaks. gsatlanta

Do I need an FI adjustment or Reset for High Altitude?

• The Short Answer is No. FI needs no changes for elevation.
• Note: The BMS-C has an air-pressure sensor.
• It's one of the beauties of FI, it adapts automatically to altitude (air pressure) changes. There's absolutely nothing to worry about here, at least not concerning the FI. Oyvind #1052, Norway
• As altitude increases, air density decreases. This will cause an unavoidable loss is power unless your engine is turbo/super-charged. The FI controller should adjust the fuel/air ratio for the change in air density (of course, the controller is only as good as the HW/SW inside it.). But the loss of power at altitude is unavoidable. Only at sea level can your engine produce it's rated horsepower. Here's the chart:

  Altitude (Feet)	Rated Power
  0K	100%
  1K	97.1%
  5K	86.2%
  10K	73.8%
  15K	62.9%

  At 10K feet, your max power will be down 26%!!! You'll notice the power loss, but the engine will still run properly. Raymo #1173
• All vehicles lose power at higher elevations-----you can do nothing about that. So you have no problem----you may find yourself holding the throttle wide open just to maintain speed uphill at the higher elevations. BigDogg #217
• The K and R FI systems don't have barometric sensors, nor do they have high-altitude lean run maps - your mixture remains the same, the O2 sensor sees to that. You get better mileage at altitude because the air is nice and thin and it takes less energy to push your bike through it! It's one of the advantages of living at 7500'. The disadvantage is that you lose a bunch of horsepower - I'm always amazed at how powerful my vehicles are when I go near sea level. Bryan #179 (NM)
• A response from Techlusion implies the O2 sensor input does not significantly affect air/fuel mixture at altitude. However, they did not say that exactly, only that I should have no problems at altitude if I tuned the bike correctly (per their instructions).
• My K-75RT (1993) has a "jumper plug" that is to be installed when exceeding 5000 feet in altitude. I have since installed it permanently, cut the jumper, and now use a "locking" switch (reachable from the seat while riding) to toggle into the "high altitude mapping" when needed. Marty #436-Chicago-97 F650F
• After a day of climbing two passes of 9,000+ feet I can say that the combination of NOT having the O2 sensor connected and the Techlusion box worked just fine. I noticed no excess richness or serious lack of power. Not really practical to try it with and without so I'll just say that I had no problems with the setup. In fact, I was quite happy with the way the bike ran for the 500 miles and 9.5 hours of saddle time. BradG 1002, N, CA '01GS

Is the BMS-C a "learning" fuel injection unit?

• It is not "smart" in the traditional EFI way, but it does store certain values in its brain. The CPU on the BMS-C has a small area of "memory" which is used to store certain "values" (although we are not 100% sure what these values are). This area of memory is probably used to store the fault codes. The reason the BMS-C reset methods suggest 15mins for the power to be disconnected is it takes about 15mins before the values are lost from this small area of "memory" on the CPU. Winter #1935
• I think what he's getting at is that even with 2K of RAM, the computer can easily store some offsets from factory presets for fuel. For example, the computer knows that for a given RPM, throttle opening, and ambient air pressure that it should give X fuel, per the factory preset. It also knows via the O2 sensor if this is rich or lean. So it can apply a fudge factor for that combination to get the O2 reading that it wants and store it in the 2K of RAM. This is the learning part. With 2K it can't get too fancy, but certainly could learn fudge factors for a variety of conditions. dinskeep
• I have been thinking about it some more, and what it comes down to is this: The BMS-C has a small bit of memory in which to store things. What it stores in that memory is not entirely known. What happens to those values when you turn the key off is unknown. When the battery is disconnected for more than X minutes, those values are definately lost. Winter #1935
• According to "Motorcycle Fuel Injection Handbook" (Adam Wade, (c) 2004), p116... "Bosch fuel injection systems for cars are among the most sophisticated in the world. So it's fairly safe to bet that some models out there have knock detection, in addition to O₂ sensor feedback. A similar system made by Hella for the BMW F650 (called the BMS-C, for the German equivalent of BMW Compact Controller) has been confirmed as a learning system, with semi-permanent trim adjustments made automatically by comparing O₂ sensor values against target values under different operating conditions. Only by disconnecting the battery are the trims reset to 0."

Do the F650 Fuel Injected models have an anti-knock sensor?

• No

Strange Tach (RPM) behaviour?

• If you are experiencing strange tach behaviour, you should check several things: 1) Check the BMS-C connector and all the sensor connections, 2) Clean the throttle body, 3) Check the Service Bulletins for upgrades to the BMS-C software, 4) Try resetting the BMS-C, 5) Check for "sticky" throttle cables / clean your throttle body up, 6) Have your local dealer check for fault codes.
• On single spark FI bikes, the BMS-C will keep the revs higher as you roll to a stop with the clutch in. Once you are stopped the revs should drop down to about 1500rpm.
• Some people find the tach does "lag" behind the engine speed - particularly on rapid accel / decel.
• On some FI bikes, after riding for a period at high (5k+) rpm, when you come to a stop, the engine speed will read lower. While stopped you may see the tach speed drop further to 1000rpm. This is despite the engine sounding exactly the same. (Note: You would notice if the idle speed dropped below 1300rpm!).
• If you are using the throttle when starting your bike - stop it. There are reports the BMS-C takes readings from the Trottle Position Sensor when you start the bike. By applying throttle when you start the bike, these "readings" could be messing with the BMS-C.

Strange Tach (RPM) behaviour - buzzing?

• Every time I turn my bike on, the tach needle shakes and makes a "buzz" sound for a few seconds. Is this a normal thing after I reset the BMS-C?
• Yes it can be (depending on how you reset your BMS-C). Take your bike out for a good long ride (30mins or more).
• If your clock resets to zero every time you turn the bike off, check your 10A fuse - it has probably blown

FI bike keeps stalling?

• If your FI model F650 keeps stalling, check the Custom Fixes for Surging and Stalling.
• If you are using the throttle when starting your bike, stop it. There are reports this can mess with the BMS-C settings and thus when it thinks your throttle is in the "idle" postion.
• Take your bike to your local dealer - there were some software upgrades that may not have been applied to your bike. See the Service Bulletins FAQ
• Check the Hard Starting / Poor Running FAQ and the GS Hard Starting / Poor Running FAQ

How can I retrieve the fault codes / error codes?

• To retrieve the fault codes from the BMS-C, you need a MoDiTeC device - a special computer sold by BMW that communicates through the diagnostic plug. The modern name for this device is called the GT1.
• On earlier BMW motorcycles you could connect a small electronic circuit and count the flashes of a LED to work out the fault codes. The BMS-C does not allow this.
• See the alternative GS911 below.

Does anyone offer an alternative to the MoDiTeC?

• Check out http://www.hex.co.za/gs911/index.html (GS-911).
• The device supports the BMS-C, BMS-C2 and ABS-N. This means all F650GS, Dakar and CS models are supported. The G650X models will likely also be supported. For more information about the device capabilities, see the FAQ on the website. Basically it allows you to read the diagnostic codes, but does not allow you to reprogram anything.

How long does it take to update the software on a BMS-C?

• I've asked my dealer for one to try and alleviate my starting issues, and told them I wanted to watch it happen. They replied by telling me it would take an hour or two. I would have thought 10 minutes would do it. mixwhit
• My local dealer told me they would charge 1 hr labor to do a software update. Bill Mallin had his flashed maybe he'll chime in with how long it took. brewer90 #1695
• Assuming that the dealer has the update in his MoDiTec system, it should less time to flash the memory than it does to wheel your bike into the service area and connect it to the 'puter. But "an hour" gives you time to admire the goodies in the sales boutique, plus, after flashing your fool infected brain, the tech can go take a large, leisurely, healthy dump while reading the morning paper, with his time at your expense of course. Flash 412 (CO)
• It may "take an hour" or more because the dealer may have to "download" the latest version from some central BMW computer. However you should not really be charged for a full hours work - lets see: wheel your bike to the MoDiTeC, connect it up, press a few buttons and walk away, look at screen every few minutes to see when it will finish. Winter #1935

Will my bike start if the battery is flat?

• The BMS-C requires a minimum voltage.
• If you battery is flat enough to power the BMS-C, but not to actually start the bike, you may be able to push start or jump start the bike (or recharge the battery).
• Also see the Battery FAQ
• And see the GS Hard Starting FAQ

Tach needle does not return to 0rpm?

• When you turn the bike off, the tach needle should return to 0rpm. If you listen carefully, you should hear a "Tic-tic-tic" followed by a pause about 20 times. This is the tach and speedo "resetting" themselves to the zero position - if you watch closely you should see the needles moving.
• Try turning your bike on, waiting 10 seconds, and turning your bike off. Repeat this until the needle returns to the zero point.
• Note 1: Several people have reported this problem (as of mid-2006), and they often have their whole dash unit replace - suggesting there are faulty units. However BMW has not released a service bulletin about this.
• Note 2: This an actual quote from the forums - Im with BMW Motorrad USA. Im sorry to read about this problem with the tachometer on your F650. If you would like our assistance, please phone us at (800) 831-1117 or email us at CustomerRelations@bmwusa.com, and mention Reference #200619801574 so that we can help you more efficiently. BMWMotorrad

Does the BMW self correct for fuel mixtures like a vehicle does using the O2 sensor?

• It is "supposed" to correct itself I think, but when you use the TFI box you unplug the sensor so you do not mess up the "performance increase." Just installed the TFI on my bike with the open intake/exhaust and it is nice. No huge gains, but the engine is smooth as ever and the front tire is never on the pavement. matttys

3 Identical 2-pin Connectors: Which goes where?

• Just under the air box on my '05 CSA there are 3 sets of sensor wires that terminate in identical 2-pin connectors. I might have mixed them up. Where do they go?
  1. Air Temp Sensor: blue-brown/yellow-brown
  2. Injection valve: red-yellow/blue-yellow
  3. Emissions control: yellow-red/gray-red
• For single spark FI models also check the electrical documents in the GS Documentation FAQ.

Potential Causes of FI Problems?

• Check all the connectors are firmly in place and rust free
• Check all air hoses are connected correctly
• Disconnect any "Fuel Nanny's"
• Check for cracks / "unmeasured" air that could enter the engine (for example cracks in the rubber intake manifold on the throttle body).
• Battery voltage
• Spark plugs
• Plug caps
• Throttle used when starting bike
• Damaged or disconnected sensors (did you remember to reconnect the Air temp / Air flow sensor in the snorkle?)
• Speed sensor (yes it can cause erratic behaviour)

Difference between old and new Fuel Injector?

• The Bosch Part Numbers (see the Service Bulletins FAQ) for the injectors are:
  0 280 156 026 and 0 280 155 788
  You can find more information on a Bosch website: http://www.bosch.com.au/content/language1/html/2247.htm.
• The Oxygen Sensor is Bosch part number: 0 258 003 559
• for (older) Injector 0 280 156 026
  Lower O-Ring: 1 280 210 752
  Upper O-Ring: 1 280 210 752
• for (newer) injector 0 280 155 788
  Lower O-Ring: 1 280 210 752
  Upper O-Ring: 1 280 210 752
  Filter Basket: 1 287 430 752
• I also found some flow data: http://users.erols.com/srweiss/tableifc.htm
• A brief comparison shows:
  • The newer version has a filter basket
  • The newer version has a slighly higher flow rate
  • The newer version has a slighly higher Rating (cc/min)
  • At 43.5PSI, the newer version has a slightly higher grams/min
  • Ahhh heck... the "newer" version has slightly higher versions for everything.
• Basically the new injector supplies more fuel compared to the old injector. However how much fuel is actually injected is dependant on the programming, so as this injector was combined with an ECU update, it is unclear if it actually results in more fuel going into the engine, OR the same amount of fuel in a shorter burst.