This is a brand new aftermarket voltage regulator rectifier for the Yamaha WR 250 F and WR 450 F enduro four-strokes. It is a direct replacement for the original Yamaha unit and needs no modification to fit: the body measures 72 mm long by 52 mm wide by 20 mm deep, the two mounting holes are 60 mm apart centre to centre, and the part carries two plugs with four pins and four wires on a 480 mm lead, matching the factory arrangement.
RMSTATOR supply the opposite connector - the main harness side half of the plug - along with the regulator. On these models the harness connector is very often melted, corroded or otherwise degraded by the time the regulator itself fails, and a poor connection there generates the heat that destroys the next unit too. Fitting both halves together clears the fault properly. The regulator uses a higher grade of electrical components than the original equipment, to a standard the manufacturer states exceeds OEM, and every unit is tested before it leaves the factory.
Key Features
- Brand new aftermarket unit, not a rebuilt core
- Direct replacement for Yamaha 5TJ-81960 series regulators
- Matching main harness side connector supplied in the box
- Plug-and-play - two plugs, four pins, four wires, 480 mm lead
- Higher grade electrical components than the original equipment
- Regulated output of 14.5 V +/- 0.5 V
- Rated to 50 A / 500 W maximum charging current
- Every unit individually tested before dispatch
Technical Specs
| Specification |
Detail |
| Part number |
RMS020-107253 |
| Width |
52 mm |
| Length |
72 mm |
| Height |
20 mm |
| Wire length |
480 mm |
| Fixation hole spacing (centre to centre) |
60 mm |
| Number of plugs |
2 |
| Number of pins |
4 |
| Number of wires |
4 |
| Minimum charging voltage |
14.5 V +/- 0.5 V |
| Maximum charging current |
50 A / 500 W |
| Open circuit voltage |
Less than 15 V |
| Operating temperature |
-20°C to 85°C |
Vehicle Fitment Guide
| Make & Model |
Years |
| Yamaha WR 250 F |
2003-2006 |
| Yamaha WR 450 F |
2004-2006 |
OEM Part Number Cross Reference
Aftermarket replacement. OEM part numbers are listed for reference only.
| Part Number |
Manufacturer / Brand |
| 5TJ-81960-00-00 |
Yamaha |
| 5TJ-81960-01-00 |
Yamaha |
| 5TJ-81960-02-00 |
Yamaha |
| 5TJ-81960-80-00 |
Yamaha |
| RMS020-107253 |
RMSTATOR |
Frequently Asked Questions
Does it fit without modification?
Yes. This is a direct fit, plug-and-play replacement. The two plugs, the four wires on a 480 mm lead and the 60 mm mounting hole spacing all match the original Yamaha unit, so nothing needs cutting, splicing or assembling.
What is supplied with it?
The voltage regulator itself and the opposite connector, which is the main harness side half of the plug. RMSTATOR include it because these connectors are commonly melted, corroded or defective on machines of this age.
How do I confirm the old regulator has failed?
Measure the voltage across the battery terminals with the engine running and compare it against the regulated 14.5 V +/- 0.5 V figure in the specification table. No rise above resting battery voltage points to a unit that has stopped charging; a reading above 15 V points to one that has stopped regulating. Flat or swollen batteries, repeatedly blown bulbs and a discoloured connector are the usual accompanying symptoms.
Which Yamaha part numbers does this supersede?
It covers the 5TJ-81960 family: 5TJ-81960-00-00, 5TJ-81960-01-00, 5TJ-81960-02-00 and 5TJ-81960-80-00. Check the number moulded or stamped on your original unit against this list before ordering.
Dispatched from the UK · 12-month warranty · Fitment support from our technical team
