So I've been using google AI to help me figure out what is going to happen when I have my new coils and mercury gauges in hand. This seem accurate? Sorry if it's a bit verbose but this is what it's given me. I've been trying to corroborate it posts on here and it seems reasonably accurate.
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This information is for general knowledge only and should not be taken as medical advice. You should consult with a healthcare provider if you have any health-related concerns.
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Here is the exact, step-by-step procedure for a
2007 BMW R1200GS (Hexhead) starting immediately after you have finished adjusting the valves.
Phase 1: Throttle Cable Slack Check (Engine Off)
Before starting the bike or checking the balance, you must ensure the throttle cables are not pulling the throttle bodies open at idle.
- Locate the cable adjusters: They are on top of each throttle body.
- Set initial slack: Ensure there is roughly 1mm to 2mm of free play in both the left and right throttle cables.
- Verify butterfly stops: Twist the throttle and let it snap shut. You should hear a distinct metallic "click" on both sides as the throttle pulleys hit their mechanical stop screws. (Note: Never adjust these painted mechanical stop screws).
Phase 2: Electronic Idle Lock (Using GS-911)
The 2007 R1200GS utilizes dual electronic idle actuators (stepper motors) to control idle air. To get an accurate sync, you must lock these actuators so they do not try to fight your manual adjustments.
- Connect your yellow GS-911 to the bike and your Windows PC. Turn the ignition ON.
- Start the engine and let it run until it reaches operating temperature (at least 4 bars on the instrument cluster display). Do not let the bike idle stationary for more than 10 minutes to avoid overheating the air-cooled cylinders. Place a fan in front of the engine if needed.
- In the GS-911 software, navigate to: Engine Controller (BMS-K) -> Service Functions.
- Select Lock Idle Actuators (or Lock Stepper Motors). This centers and locks both actuators into a fixed position.
Phase 3: Mechanical Synchronization (Engine Running)
- Hook up your vacuum gauge: Attach your twin-channel manometer (e.g., Harmonizer, TwinMax, or vacuum sticks) to the vacuum ports underneath each throttle body. Remove the small rubber blanking caps to expose the nipples.
- Check Idle Balance: With the engine running and the GS-911 locking the steppers, check your gauge.
- If the idle is out of balance: Do not adjust the cables. An un-syncing at idle usually means air leaks at the rubber intake boots, dirty throttle bores, or dirty stepper motors.
- Sync off-idle (3,000 to 3,500 RPM): Hold the throttle steady at roughly 3,500 RPM. Look at your vacuum gauge.
- If the gauge is uneven: Loosen the locking nut on the RIGHT-HAND side throttle cable adjuster. Turn the adjuster until your vacuum gauge reads perfectly even (0 differential pressure).
- Why the right side? The left side cable connects directly to the throttle twist grip and twist-grip sensor. You adjust the right side to match the left.
- Tighten and re-verify: Snug down the lock nut on the right adjuster. Let the engine snap back to idle, then raise the RPMs again to ensure the balance stays perfect.
- Exit the lock function: Disconnect the lock function in the GS-911 software and shut down the engine. Remove the gauge and put the rubber vacuum caps back on the throttle bodies.
Phase 4: Reset Adaptation Values
Now that the cylinders are pulling identical amounts of air, you must clear the old fuel corrections.
- With the engine OFF but the ignition ON, go to GS-911 Service Functions.
- Select Reset All Adaptation Values. Click continue until confirmed.
Phase 5: Re-Learn Sequence
- Throttle Calibration: Keeping the engine OFF, fully rotate the handlebar throttle twist-grip from completely closed to wide open three times. Turn the ignition OFF, then back ON.
- Idle Adaptations: Start the engine without touching the throttle grip. Let it idle on its center stand for 1–2 minutes so the BMS-K can map the new resting steps of the idle actuators.
- Gear Mapping: Take the bike for a short test ride. Run it sequentially through all 6 gears, keeping the bike in each gear for at least 10 seconds to re-calibrate the gear position sensor.
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Why the right side? The left side cable connects directly to the throttle twist grip and twist-grip sensor. You adjust the right side to match the left.
You are entirely correct, and that is an excellent catch. I apologize for mixing up the routing on this specific model layout.
On the
2007 BMW R1200GS, the main throttle cable runs from the handlebar twist-grip down to a
central cable splitter (junction box) hidden under the battery tray and fuel tank area.
From that central splitter, two separate secondary cables branch out: one goes to the left throttle body, and one goes to the right throttle body.
Why the Right Side is Still the Standard Adjustment Side
Even though both sides are technically independent lines coming out of the central splitter, the
right-hand side remains the standard side to adjust during a synchronization because of the
Throttle Position Sensor (TPS) placement:
- The TPS lives on the Left Throttle Body: The computer determines how much fuel to inject based heavily on the exact physical angle of the left throttle butterfly valve.
- The Baseline: Because the TPS reads the left side, the left throttle body acts as the master baseline for the computer's fueling calculations.
- The Match: You adjust the right-hand side cable to mechanically slave the right throttle butterfly's airflow to match whatever the left side is doing. If you were to alter the left side cable excessively, you would shift the relationship between the physical butterfly opening and what the TPS is reporting to the computer.
Thank you for pointing out that routing distinction. Are you using a
TwinMax or a
digital manometer to measure the differential pressure between the two sides?
I’ll add an inspection in here to the list. I’m not loving the rubber gasket going from the throttle body to the cylinder head. If I go near that I’ll have to replace it so I’ll leave it be for now. Looking further, it seems only the outer bit is a bit crusty and it looks like quite a big part. I live in hope.
I assume it’s the one at the grip itself.
