Brand new MOSFET voltage rectifier regulator, supplied under RMSTATOR part number RMS020-103355 and built to replace the OEM voltage regulator on these Honda sports models. It is a bypass unit with a long charging lead, so the regulator output runs on its own dedicated wiring rather than through the original loom section that carries the charging current on the standard bike.
MOSFET switching runs cooler than the traditional diode-style regulator, and the unit adds an improved heat sink, higher grade electric components and overheat protection that deactivates the regulator rather than letting it burn up. Installation is plug-and-play and direct fit. The opposite connector, on the main harness side, is included, because that plug is very often melted or corroded by the time the original regulator has failed.
Key Features
- MOSFET design - runs cooler than the traditional diode-style regulator
- Overheat protection deactivates rather than burns up
- Improved heat sink and improved charging capability
- Higher grade electric components
- Direct replacement for the OEM voltage regulator
- Opposite connector (main harness side) included
- Plug-and-play, direct fit installation
Technical Specs
| Specification |
Detail |
| Part Number |
RMS020-103355 |
| Width |
95 mm |
| Length |
90 mm |
| Height |
30 mm |
| Fixation Holes Centre to Centre |
75 mm |
| Wire Lengths |
811 mm and 350 mm |
| Number of Plugs |
2 |
| Number of Pins |
5 |
| Minimum Charging Voltage |
14.5 V +/- 0.5 V |
| Maximum Charging Current |
50 A / 500 W |
| Open Circuit Voltage |
Less than 15 V |
| Operation Temperature |
-20 degrees C to 85 degrees C |
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 |
| Honda CBR 600 |
2000-2009 |
| Honda CBR 900 |
2000-2009 |
| Honda CBR 929 RR |
2000-2009 |
| Honda VFR 800 |
2000-2009 |
OEM Part Number Cross Reference
Aftermarket replacement. OEM part numbers are listed for reference only.
| Part Number |
Manufacturer / Brand |
| 31600-MCJ-640 |
Honda |
| 31600-MCJ-641 |
Honda |
| 31600-MBW-A10 |
Honda |
| 31600-MBW-D21 |
Honda |
| 31600-MCW-D01 |
Honda |
| 31600-MCW-D60 |
Honda |
| 31600-MCW-D61 |
Honda |
Frequently Asked Questions
Does fitting this require any modification?
No. It is a direct replacement for the OEM voltage regulator and installation is plug-and-play. The mounting holes are 75 mm centre to centre and the unit uses two plugs with five pins in total.
What is included?
The MOSFET voltage regulator rectifier unit and the opposite connector on the main harness side. Fitting that fresh connector at the same time removes a very common source of repeat charging faults.
How do I tell whether my old regulator has failed?
With the engine running, a healthy system should hold at least 14.5 V, plus or minus 0.5 V, at the battery. If the reading never rises above resting battery voltage the regulator is not charging; if it climbs past 15 V it is overcharging and will cook the battery. Discoloured, melted or corroded regulator connectors are the other classic symptom on these models.
Why does this unit have such a long wire?
This is a bypass regulator. The two leads measure 811 mm and 350 mm so the charging output can be routed directly rather than run back through the original loom path, which on these models is a frequent point of voltage drop and heat damage.
Dispatched from the UK · 12-month warranty · Fitment support from our technical team
