Yamaha YZF-R1 Starter Solenoid Relay 12V 2-Fuse
Replacement starter solenoid / starter relay for Yamaha YZF-R1 applications using the compatible Yamaha two-fuse relay pattern. The relay acts as the high-current electrical switch between the battery and starter motor when the starter button is pressed.
Components Identified From the Product Photos
- Black moulded starter-solenoid / relay body
- Two heavy-current brass threaded terminal studs for battery and starter-motor cables
- Brass terminal nuts for the high-current cable connections
- Two blade-fuse positions under translucent protective fuse covers
- Low-current control connector / terminal section between the main connections
- Insulated base/body designed to locate in the motorcycle or ATV relay mounting area
Key Specification
- Electrical system: 12V
- Relay type: High-current starter solenoid / electromagnetic starter switch
- Fuse arrangement: Twin 30A fuse positions on the common 4SV/4YR-pattern equivalent family
- Main connections: Two threaded high-current studs
- Condition: New aftermarket replacement
A comparable 4SV/4YR-family replacement is specified at 12V and 150A with 30A fuses. This is cross-reference specification data for the equivalent relay family rather than an individual factory test certificate for the supplied unbranded item.
Yamaha OE & Aftermarket Cross-References
- Yamaha 4YR-81940-00-00
- Yamaha 4YR-81940-01-00
- Yamaha 4YR-81940-02-00
- Yamaha 4DN-81940-00-00
- Yamaha 4DN-81940-12-00
- Yamaha 5JW-81940-00-00
- Yamaha 5JW-81940-02-00
- Yamaha 1D0-81940-00-00 / 01-00 / 02-00 (selected R1 years)
- Yamaha 5SL-81940-10-00 / 11-00 / 12-00 (R6 family)
- NICHE 519-CSS2239L
- Wemoto AI5484
Primary reference family for this listing: 4YR-81940-00-00.
The supplied product is unbranded aftermarket, not a genuine Yamaha, RM Stator, NICHE, Wemoto or DB Electrical relay. All OE and manufacturer numbers are supplied only to help identify the correct interchange family.
Listed Application
Yamaha YZF-R1
The YZF-R1 used several Yamaha starter-relay suffixes over its model run. This listing is for bikes whose original relay matches the pictured two-fuse 4YR/5JW/1D0 cross-reference family.
Compatibility Check Before Ordering
- Compare the complete relay shape with the product photographs
- Confirm the relay has the same two heavy-current threaded studs and terminal orientation
- Compare the fuse arrangement and fuse-cover positions
- Compare the low-current control connector, pin arrangement and keying
- Check how the original relay locates in its rubber holder or mounting area
- Compare the Yamaha OE number on the original relay with the cross-reference family above where possible
Yamaha used several starter-relay part-number suffixes across different years and markets. Matching the original part number and physical connector/fuse layout is more reliable than ordering by model name alone.
Electrical Safety & Installation
Disconnect the battery before replacing a starter relay. Transfer the battery and starter-motor cables one at a time so they remain on the correct terminals, tighten the terminal nuts securely without over-stressing the relay body, and confirm the fuse rating matches the motorcycle or ATV specification. A faulty battery, starter motor, cable or charging system can damage a replacement relay or cause repeated fuse failure.
What Is Included
One starter solenoid / relay assembly with terminal nuts, fuse positions and covers as shown in the product photographs. Battery cables, starter motor, mounting rubber, wiring loom and additional vehicle-side hardware are not included unless visibly shown.
Delivery & Returns
- Free UK delivery with an estimated 2–3 working-day service
- 30-day returns, subject to the item being returned in its original condition