What causes Throttle-by-wire glitches and stalling at idle on the Triumph Bonneville Street Twin?

Test idle smoothness, look for ECU recall history Estimated fix cost: $100-$300

What causes Regulator/rectifier failure killing battery on the Triumph Bonneville Street Twin?

Check battery voltage at idle, inspect R/R connector Estimated fix cost: $150-$400

Look under engine for dried coolant residue trails Estimated fix cost: $200-$450

Known issues to inspect before buying a used Triumph Bonneville Street Twin. What to check and how much repairs cost.

MODERATE

Test idle smoothness, look for ECU recall history

Fix cost: $100-$300

SERIOUS

Check battery voltage at idle, inspect R/R connector

Fix cost: $150-$400

MODERATE

Look under engine for dried coolant residue trails

Fix cost: $200-$450

☐Verify all Triumph safety recalls completed

☐Check service history for 10k mile intervals

☐Test ride for smooth throttle response

☐Inspect for any coolant or oil seepage

Generally solid, minor electrical gremlins on early models