9-Tooth Starter Motor for Yamaha WR450F 2003–2006 5TJ-81890-10

Product Overview

Replace a worn, weak, noisy, or failed starter motor with this 9-tooth electric starter motor, designed for select Yamaha WR450F 450cc off-road motorcycle applications from 2003–2006.

The starter motor helps crank the engine when the electric start button is pressed. A failing starter motor may cause slow cranking, clicking, intermittent starting, no-crank issues, grinding noise, or failure to start even when the battery is charged.

This replacement starter motor features a 12V system, 9-tooth gear, and CW rotation based on supplied product data. Please compare your original starter motor’s OEM number, tooth count, rotation direction, mounting points, electrical terminal, body shape, gear position, and overall design before ordering.

Product Compatibility

Important Fitment Note:
This part is not selected by model name alone. Yamaha WR450F models may use different starter motor versions depending on year, market, engine version, gear count, rotation direction, mounting points, and electrical terminal style. Please confirm your original starter motor matches the listed OEM/reference number, 9-tooth gear, CW rotation, and overall shape before ordering.

Specifications

Key Features

• 9-tooth electric starter motor for select Yamaha WR450F off-road motorcycles
• Designed for matching 2003–2006 WR450F electric starting systems
• Replaces common Yamaha starter references 5TJ-81890-00, 5TJ-81890-10, 5TJ-81890-20, and 5TJ-81890-21
• 12V CW starter motor design for matching WR450F applications
• Helps restore electric start function when the original starter motor is weak, worn, noisy, or failed
• Gear-reduction starter design helps crank the high-compression 450cc engine more effectively
• Precision-built replacement style supports stable cranking performance
• Direct replacement style, but original gear count, rotation direction, terminal type, and mounting layout must be checked before installation

OEM Cross Reference

Please use the OEM/reference number together with physical fitment checks. If your original starter motor has a different gear tooth count, rotation direction, shaft style, mounting hole layout, electrical terminal, body shape, or mounting position, this part may not fit.