A brand new aftermarket voltage regulator rectifier for the 1982-1983 Kawasaki GPz550 and KZ 550, supplied as a direct replacement for the original unit. It rectifies alternator output to DC and holds charging voltage steady, curing the flat batteries, dimming lights and erratic charging readings that appear once the factory regulator breaks down.
Installation is plug-and-play and direct fit with no assembly required. The unit carries 6 wires across 2 plugs and mounts on 55 mm centres, matching the original layout. A higher grade of electrical components is used than in the original equipment, so regulation stays within specification rather than drifting as the unit heats up in traffic. All products shipped are tested.
Key Features
- Direct replacement to your original unit
- Plug-and-play, direct fit, easy installation
- No assembly required
- Higher grade of electrical components, exceeding OEM equipment quality
- Compact 85 x 61 x 25 mm case with 55 mm mounting centres
- All products shipped are tested
Technical Specs
| Specification |
Detail |
| Width |
85 mm |
| Length |
61 mm |
| Height |
25 mm |
| Fixation holes (centre to centre) |
55 mm |
| Wire length |
145 mm |
| Number of plugs |
2 |
| Number of pins |
6 |
| Number of wires |
6 |
| 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 to 85 degrees Celsius |
Vehicle Fitment Guide
| Make & Model |
Years |
| Kawasaki GPz550 |
1982-1983 |
| Kawasaki KZ 550 |
1982-1983 |
OEM Part Number Cross Reference
Aftermarket replacement. OEM part numbers are listed for reference only.
| Part Number |
Manufacturer / Brand |
| 21066-1025 |
Kawasaki |
Frequently Asked Questions
Does this unit need modification to fit?
No. It is plug-and-play and direct fit with no assembly required, using 2 plugs, 6 pins and 55 mm mounting centres to match the original unit.
What is included?
The voltage regulator rectifier unit with its 145 mm leads and connectors, ready to plug in.
How can I tell whether my old regulator has failed?
Charge the battery fully, then measure across the terminals with the engine running. A healthy system reads around 14.5 V plus or minus 0.5 V. A reading stuck at resting battery voltage, or one climbing past 15 V, usually means the regulator rectifier has failed.
Does the same unit cover the KZ 550 as well as the GPz550?
Yes. This regulator covers both the GPz550 and the KZ 550 for the 1982 and 1983 model years. Check the OEM number 21066-1025 on your original part before ordering.
Dispatched from the UK · 12-month warranty · Fitment support from our technical team
