What causes Stator and charging system failure on the Yamaha Wr125r?

Battery not charging, voltage drop under load Estimated fix cost: $150-$300

What causes Valve clearance neglect causing hard starting on the Yamaha Wr125r?

Ask for service history, test cold start behavior Estimated fix cost: $80-$200

Chain slack, sprocket tooth wear or hooking Estimated fix cost: $80-$150

Cold start difficulty, hesitation, black smoke at idle Estimated fix cost: $50-$150

Known issues to inspect before buying a used Yamaha Wr125r. What to check and how much repairs cost.

MODERATE

Cold start difficulty, hesitation, black smoke at idle

Fix cost: $50-$150

SERIOUS

Battery not charging, voltage drop under load

Fix cost: $150-$300

MODERATE

Ask for service history, test cold start behavior

Fix cost: $80-$200

MINOR

Chain slack, sprocket tooth wear or hooking

Fix cost: $80-$150

☐Check for service history and valve checks

☐Test battery voltage and charging output

☐Inspect chain, sprockets, and rear wheel bearings

☐Cold start the bike, listen for top-end noise

Solid if maintained, fragile if neglected