A starter relay solenoid is the heavy-duty switch that lets the small current from your start button control the very large current the starter motor needs. When the coil inside the solenoid is energised it closes a pair of high-current contacts and the battery is connected straight to the starter. Those contacts take a hard life, and once they pit or burn the machine will click without cranking, or crank far more slowly than it should.
This is RMSTATOR part RM09015, a brand new starter relay solenoid switch built as a direct replacement for the original unit. RMSTATOR state that the quality exceeds the OEM equipment and that all units are tested before shipment. It is a four-terminal design with a single plug in a 46 mm x 33 mm x 51 mm body, and it covers a wide spread of KTM two-stroke and four-stroke enduro and motocross machines as well as Yamaha YZF sports models.
Key Features
- Brand new unit - not remanufactured and not a repaired core
- Direct replacement to the original unit
- Quality exceeds the OEM equipment, according to RMSTATOR
- Every unit tested prior to shipment
- Four terminals with a single plug
- Compact 46 mm x 33 mm x 51 mm body
- Cross references thirteen KTM and Yamaha OEM part numbers
Technical Specs
| Specification |
Detail |
| Part number |
RM09015 |
| Component |
Starter relay solenoid |
| Height |
51 mm |
| Length |
46 mm |
| Width |
33 mm |
| Number of terminals |
4 |
| Number of plugs |
1 |
| Condition |
New, tested before shipment |
Vehicle Fitment Guide
Years shown are the overall coverage span for this part. Please confirm against the OEM part number on your original unit before ordering.
| Make & Model |
Years |
| KTM 250 / 300 XC-W |
1995-2025 |
| KTM 250 / 300 XC-F |
1995-2025 |
| KTM 250 / 300 SX-F |
1995-2025 |
| Yamaha YZF R6 |
1995-2025 |
| Yamaha YZF 600 |
1995-2025 |
OEM Part Number Cross Reference
Aftermarket replacement. OEM part numbers are listed for reference only.
| Part Number |
Manufacturer / Brand |
| 58211058000 |
KTM |
| 5VN-81940-00-00 |
Yamaha |
| 5LW-81940-02-00 |
Yamaha |
| 4FU-81940-00-00 |
Yamaha |
| 4FU-81940-01-00 |
Yamaha |
| 4FU-81940-02-00 |
Yamaha |
| 4JG-81940-00-00 |
Yamaha |
| 4JG-81940-10-00 |
Yamaha |
| 4JG-81940-12-00 |
Yamaha |
| 4DN-81940-00-00 |
Yamaha |
| 4DN-81940-10-00 |
Yamaha |
| 4DN-81940-11-00 |
Yamaha |
| 4DN-81940-12-00 |
Yamaha |
Frequently Asked Questions
Does this solenoid need any modification to fit?
No. RM09015 is a direct replacement to the original unit, with the same four-terminal layout and single plug, so it fits the original mounting and wiring.
What is included?
A single starter relay solenoid unit, tested before shipment. No additional components or accessories are listed by RMSTATOR for this part number.
How do I know my old solenoid has failed?
The usual sign is a single click, or a rapid chatter, from the solenoid when you press the start button while the lights stay bright. A solenoid with worn contacts may also crank the engine slowly, or start reliably only when everything is cold. Check the battery, its terminals and the earth strap before condemning the solenoid.
My bike is a KTM but my old solenoid carries a Yamaha number - is that normal?
Yes. The same solenoid design is shared across several manufacturers, which is why the cross reference above lists the KTM number 58211058000 alongside a long run of Yamaha 81940 numbers. Match the number on your original unit to the table rather than going by the badge on the tank.
Dispatched from the UK · 12-month warranty · Fitment support from our technical team
