What causes Worn or seized piston rings on the Yamaha Rdx 135?

Blue smoke on startup, low compression test reading Estimated fix cost: $80-$150

What causes Clogged or damaged carburetor on the Yamaha Rdx 135?

Hard starting, rough idle, poor throttle response Estimated fix cost: $20-$60

Knocking noise, vibration at high RPM Estimated fix cost: $120-$250

Fuel discoloration, engine sputtering under load Estimated fix cost: $30-$80

Known issues to inspect before buying a used Yamaha Rdx 135. What to check and how much repairs cost.

SERIOUS

Blue smoke on startup, low compression test reading

Fix cost: $80-$150

MODERATE

Hard starting, rough idle, poor throttle response

Fix cost: $20-$60

SERIOUS

Knocking noise, vibration at high RPM

Fix cost: $120-$250

MODERATE

Fuel discoloration, engine sputtering under load

Fix cost: $30-$80

☐Run engine cold to check startup smoke

☐Check for frame cracks near engine mounts

☐Inspect exhaust port for carbon buildup

☐Test ride above 7000 RPM powerband

Decent if maintained, punishing if neglected