What causes Carb sync and jetting issues over time on the Yamaha Yzf600r Thundercat?

Rough idle, hesitation, uneven throttle response between cylinders Estimated fix cost: $80-$200

What causes Coolant leak from water pump seals on the Yamaha Yzf600r Thundercat?

Oil contamination, milky oil, weep hole dripping coolant Estimated fix cost: $100-$250

Cold start rattling noise from top end on startup Estimated fix cost: $150-$400

Visible rust, exhaust ticking, black soot around header joints Estimated fix cost: $50-$300

Known issues to inspect before buying a used Yamaha Yzf600r Thundercat. What to check and how much repairs cost.

MODERATE

Rough idle, hesitation, uneven throttle response between cylinders

Fix cost: $80-$200

MODERATE

Oil contamination, milky oil, weep hole dripping coolant

Fix cost: $100-$250

SERIOUS

Cold start rattling noise from top end on startup

Fix cost: $150-$400

MINOR

Visible rust, exhaust ticking, black soot around header joints

Fix cost: $50-$300

☐Check for oil leaks around engine cases

☐Cold start the bike, listen carefully

☐Inspect frame for crash damage or welds

☐Verify coolant is clean not milky

Solid middleweight, maintain carbs and coolant system