What causes Throttle body sync causing rough idle/surging on the Bmw R 850 Gs?

Ride at low speed, feel for hunting idle Estimated fix cost: $50-$150

What causes Final drive spline wear and failure on the Bmw R 850 Gs?

Check clunking on acceleration, inspect spline grease Estimated fix cost: $300-$800

ABS warning light on dash during test ride Estimated fix cost: $200-$600

Blue smoke on startup, check spark plug condition Estimated fix cost: $150-$400

Known issues to inspect before buying a used Bmw R 850 Gs. What to check and how much repairs cost.

MODERATE

Ride at low speed, feel for hunting idle

Fix cost: $50-$150

SERIOUS

Check clunking on acceleration, inspect spline grease

Fix cost: $300-$800

MODERATE

ABS warning light on dash during test ride

Fix cost: $200-$600

MINOR

Blue smoke on startup, check spark plug condition

Fix cost: $150-$400

☐Check service history, especially valve adjustments

☐Inspect final drive for play or clunking

☐Test all electrics and ABS function

☐Look for frame corrosion or crash damage

Solid but needs regular maintenance attention