BMW G 650 Xchallenge (2007-2010): The Ultimate Maintenance & Service Guide
The BMW G 650 Xchallenge (Model Code 0165) is a legendary “Hard Enduro” machine produced between 2007 and 2010. Powered by the reliable 652cc Rotax-designed single-cylinder engine, it is praised for its lightweight chassis and off-road prowess. However, to keep this Bavarian thumper performing at its peak, a strict maintenance regimen is required.
Table of Contents
- 1. Technical Specifications & Capacities
- 2. Routine Maintenance Schedule
- 3. Engine Oil & Filter Change (Dry Sump System)
- 4. Valve Clearance Inspection
- 5. Maintaining the Continental Air Shock
- 6. Cooling System & Radiator Care
- 7. Drivetrain: Chain, Sprockets, and Swingarm
- 8. Electrical System & Battery
- 9. Common Issues & Troubleshooting
1. Technical Specifications & Capacities
Before turning a wrench, ensure you have the correct fluids and parts for the G 650 Xchallenge.
| Component | Specification |
|---|---|
| Engine Type | Liquid-cooled, single-cylinder, 4-stroke, 4 valves |
| Displacement | 652 cc |
| Oil Capacity (with filter) | 2.3 Liters (Approx. 2.43 US Quarts) |
| Oil Type | SAE 10W-40 or 15W-50 (API SF or higher) |
| Spark Plug | NGK DR8EB (2 per cylinder) |
| Coolant Capacity | 1.2 Liters (50/50 Nitrite-free antifreeze) |
| Fuel Tank Capacity | 9.5 Liters (including 2L reserve) |
2. Routine Maintenance Schedule
BMW recommends service intervals every 10,000 km (6,000 miles). However, for bikes used heavily off-road, these intervals should be halved.
- Every 10,000 km: Change engine oil and filter, check valve clearance, inspect brake pads, and clean the air filter.
- Every 20,000 km: Replace spark plugs, change brake fluid, and inspect the cooling system.
- Every 2 Years: Flush coolant and replace the fork oil.
3. Engine Oil & Filter Change (Dry Sump System)
The G 650 Xchallenge uses a dry sump lubrication system. This means the oil is stored in an external tank (located in the frame/upper area) rather than just the bottom of the engine. Changing the oil requires a two-step draining process.
Steps for Oil Change:
- Warm the Engine: Run the bike for 5-10 minutes to ensure the oil is warm and flows easily.
- Drain the Crankcase: Remove the drain plug located at the bottom of the engine (24mm bolt). Replace the copper crush washer.
- Drain the Oil Tank: Locate the drain plug on the left side of the frame near the cylinder head. Be careful, as oil may spray onto the front wheel.
- Replace the Filter: The oil filter is located on the right side of the engine. Remove the three bolts, pull the old filter, and insert a new one (ensure the black rubber seal faces inward).
- Refilling: Add 1.7 liters of oil. Start the engine and let it idle for 30 seconds. Switch off, then add the remaining 0.6 liters until the level is correct on the dipstick.
4. Valve Clearance Inspection
The Rotax engine is robust, but the valves must be checked every 10,000 km. The Xchallenge uses a shim-under-bucket design.
Specifications:
- Intake: 0.03 mm to 0.11 mm
- Exhaust: 0.25 mm to 0.33 mm
To check clearances, you must remove the seat, the “fake” tank plastics, and the valve cover. The engine must be stone cold when performing this check. If the clearances are out of spec, you will need to remove the camshafts to replace the shims.
5. Maintaining the Continental Air Shock
One of the most unique features of the Xchallenge is the Continental Air Damping System. Unlike traditional coil-over shocks, this uses compressed air.
Maintenance Tips:
- Check Pressure Regularly: Use the integrated bubble level on the swingarm. When you are sitting on the bike in your riding gear, the bubble should be centered.
- Keep it Clean: Dirt and mud can score the piston rod. Wipe the shock down after every muddy ride.
- Seal Lubrication: Use a tiny amount of silicone spray on the wiper seal to keep it supple and prevent air leaks.
6. Cooling System & Radiator Care
Because the Xchallenge is often ridden at low speeds on technical trails, the cooling system is vital. The radiator is somewhat exposed, so a radiator guard is a highly recommended aftermarket addition.
- Check the Fan: Ensure the electric fan spins freely. It is common for small rocks to jam the fan blades.
- Coolant Level: Check the expansion tank located on the right side of the bike behind the radiator shroud.
- Flush: Every two years, drain the system by removing the lowest hose on the water pump. Refill with a silicate-free, aluminum-safe coolant.
7. Drivetrain: Chain, Sprockets, and Swingarm
The Xchallenge uses a 520-pitch O-ring chain. Off-road riding accelerates wear on these components.
Chain Tension:
The chain should have 40mm to 50mm of slack when the bike is on its side stand. A chain that is too tight will put excessive stress on the countershaft bearing, which is an expensive repair.
Swingarm Pivot:
The swingarm and linkage bearings are often neglected. Every 20,000 km, the swingarm pivot should be greased. If you ride through deep water frequently, do this more often to prevent the bolt from seizing in the engine cases.
8. Electrical System & Battery
The G 650 X series has a few known electrical quirks that owners should monitor.
- Battery Access: The battery is located under the airbox cover (where the fuel tank would be on a traditional bike). It is a YTZ10S equivalent.
- Voltage Regulator/Rectifier: This unit is located on the right side of the frame. Ensure the connections are clean and free of corrosion. If your battery isn’t charging, this is the first place to look.
- Wiring Loom Rubbing: Inspect the wiring harness where it passes near the headstock and under the seat. Vibration can cause the insulation to rub through, leading to shorts.
9. Common Issues & Troubleshooting
The “Hot Start” Issue
Some G 650 Xchallenges struggle to start when the engine is hot. This is often caused by a faulty auto-decompression lever on the exhaust camshaft. If the bike cranks slowly or “kicks back” when hot, the decompression mechanism may need replacement.
Clutch Cable Routing
The clutch cable on the Xchallenge is prone to fraying if not routed perfectly. Ensure there are no sharp bends and lubricate the cable ends with a drop of light oil during every service. Many owners carry a spare cable zip-tied alongside the active one for quick trailside repairs.
Water Pump Seal Failure
The Rotax engine uses a dual-seal system on the water pump. If you notice a mixture of oil and coolant (milky residue) or see coolant weeping from the small “weep hole” at the bottom of the water pump housing, the seals and shaft need replacement. This is a common high-mileage maintenance item.
Fuel Pump Reliability
The fuel pump is located inside the under-seat tank. If the bike bogs down or refuses to start after being left in the sun, the fuel pump may be failing. Listen for the “prime” sound when you turn the key; if it’s silent, the pump or relay is likely the culprit.
Conclusion
The BMW G 650 Xchallenge is a specialized tool that rewards the owner who pays attention to its unique needs. By following this maintenance guide, you ensure that your 0165 model remains a reliable companion for both daily commutes and trans-continental adventures. Regular oil changes, attention to the air shock, and keeping an eye on the cooling system are the keys to longevity for this classic Bavarian enduro.
Disclaimer: This guide is for informational purposes. Always consult the official BMW Service Manual before performing repairs.
