This is a brand new starter relay solenoid switch, the heavy-duty relay that sits between the battery and the starter motor. When you press the start button the handlebar circuit energises the solenoid coil, which closes a set of high-current contacts and lets the full battery current reach the starter. It is the component that produces the single loud click when a starting circuit is healthy but the battery is flat, and the component that produces nothing at all when the solenoid contacts themselves have burned out.
The unit is rated at 150 A for 30 seconds and carries four terminals with a single plug for the low-current trigger wiring. It measures 50 mm long by 40 mm wide by 50 mm high. The manufacturer states that the quality exceeds the OEM equipment, and every unit is tested before it is shipped. The product photographs are accurate, so if you are in any doubt about which solenoid you have, compare the item shown against your original part before ordering.
Key Features
- Brand new starter relay solenoid switch, not a refurbished unit
- Rated at 150 A for 30 seconds
- Four terminals with a single plug for the trigger circuit
- Compact 50 mm x 40 mm x 50 mm body
- Quality stated to exceed the OEM equipment
- Every unit is tested before dispatch
- Covers Husqvarna, KTM and Yamaha applications with a shared OEM part number family
Technical Specs
| Specification |
Detail |
| Part number |
RMS090-106117 |
| Height |
50 mm |
| Length |
50 mm |
| Width |
40 mm |
| Number of terminals |
4 |
| Number of plugs |
1 |
| Rate |
150 A 30 S |
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 |
| Husqvarna FC 250 |
1998-2026 |
| Husqvarna FE 350 |
1998-2026 |
| KTM 690 Duke |
1998-2026 |
| KTM 890 Duke |
1998-2026 |
| Yamaha YZF R1 |
1998-2026 |
| Yamaha YZF R6 |
1998-2026 |
OEM Part Number Cross Reference
Aftermarket replacement. OEM part numbers are listed for reference only.
| Part Number |
Manufacturer / Brand |
| 4YR-81940-01-00 |
Yamaha |
| 4YR-81940-00-00 |
Yamaha |
| 4YR-81940-02-00 |
Yamaha |
| 5JW-81940-00-00 |
Yamaha |
| 5JW-81940-01-00 |
Yamaha |
| 5JW-81940-02-00 |
Yamaha |
| 2C0-81940-00-00 |
Yamaha |
| 76211058000 |
KTM / Husqvarna |
Frequently Asked Questions
Is this a direct replacement?
Yes. It replaces the original solenoid with the same four terminals and single trigger plug, so no modification is needed. Match your original against the OEM numbers listed above before ordering.
What is included?
You receive the starter relay solenoid switch itself, with four terminals and one plug.
How do I tell whether the old solenoid has failed?
With a charged battery, press the start button. A single sharp click and no cranking usually means the contacts inside the solenoid have burned and are no longer passing current. No click at all points to the trigger circuit or the coil. If the starter turns when you bridge the two heavy terminals with a suitable tool but not on the button, the solenoid is the fault.
What current can it carry?
It is rated at 150 A for 30 seconds, which is the short high-current burst a starter motor draws while cranking.
Dispatched from the UK · 12-month warranty · Fitment support from our technical team
