What causes Throttle body sync drift causing rough idle on the Kawasaki Ninja Zx-4rr?

Idle quality, rough running at low RPM on test ride Estimated fix cost: $150-$300

What causes Exhaust header heat discoloration and bluing on the Kawasaki Ninja Zx-4rr?

Inspect headers for excessive bluing or warping signs Estimated fix cost: $0-$50

Rear tire wear pattern, center flat spot present Estimated fix cost: $200-$350

Known issues to inspect before buying a used Kawasaki Ninja Zx-4rr. What to check and how much repairs cost.

MODERATE

Idle quality, rough running at low RPM on test ride

Fix cost: $150-$300

MINOR

Inspect headers for excessive bluing or warping signs

Fix cost: $0-$50

MODERATE

Rear tire wear pattern, center flat spot present

Fix cost: $200-$350

☐Check service history and oil change intervals

☐Inspect frame for track day crash damage

☐Verify no ECU tune or map modifications

☐Test all four cylinders firing cleanly

Generally solid, newer model, low long-term data