What causes Carb diaphragm cracking causing rough idle on the Triumph Thruxton 900?

Rev throttle, listen for flat spots or hesitation Estimated fix cost: $50-$150

What causes Cam chain tensioner wear causing rattle on the Triumph Thruxton 900?

Cold start rattle at idle, disappears when warm Estimated fix cost: $200-$500

Oil residue on lower fork legs, handling vagueness Estimated fix cost: $150-$300

Voltage test at idle, should read 13.5-14.5V Estimated fix cost: $300-$600

Known issues to inspect before buying a used Triumph Thruxton 900. What to check and how much repairs cost.

MODERATE

Rev throttle, listen for flat spots or hesitation

Fix cost: $50-$150

SERIOUS

Cold start rattle at idle, disappears when warm

Fix cost: $200-$500

MODERATE

Oil residue on lower fork legs, handling vagueness

Fix cost: $150-$300

SERIOUS

Voltage test at idle, should read 13.5-14.5V

Fix cost: $300-$600

☐Check service history and cam chain maintenance

☐Test ride cold to catch rattle noises early

☐Inspect carbs for diaphragm tears or corrosion

☐Battery voltage test and charging system check

Solid bike, well maintained examples last long