This is a complete charging system upgrade kit for the Aprilia RSV4 and Tuono V4, built to address the known stator, flywheel and voltage regulator failures on these models. The original flywheels were fitted with excessively strong magnets, which drove the stator output higher than the bike actually needs. The extra output turns into heat, and that heat is what eventually burns out the stator windings.
The kit solves the problem at its source rather than simply replacing the burnt part. A Kokusan recall-type flywheel with lower strength magnets brings the charging output back down to a level matched to the motorcycle's electrical demand, so the triple-tested heavy-duty stator supplied alongside it runs cooler and lasts. A voltage regulator rectifier, a crankcase cover gasket and the correct 36 mm flywheel puller are included, so the whole job can be done in one go without hunting for extra parts.
Key Features
- Complete charging system upgrade - flywheel, stator, regulator, gasket and puller in one kit
- Heavy-duty Kokusan recall-type OEM flywheel with lower strength magnets
- Reduced stator output and reduced heat generation for long term reliability
- Triple-tested heavy-duty stator
- Voltage regulator rectifier rated to 50 A / 500 W
- Crankcase cover gasket included
- 36 mm x 1.5 right hand flywheel puller included
- Regulator operating temperature range -20 C to 85 C
Technical Specs
| Specification |
Detail |
| Stator interior diameter |
43 mm |
| Stator exterior diameter |
105 mm |
| Stator thickness |
13.8 mm |
| Stator wire length (stator to grommet) |
125 mm |
| Stator wire length (grommet to plug) |
320 mm |
| Stator wires / plugs / pins |
3 wires, 1 plug, 3 pins |
| Stator resistance yellow to yellow |
0.3 ohms +/-20% |
| Flywheel exterior diameter |
121 mm (second diameter 119 mm) |
| Flywheel interior diameter |
107 mm |
| Flywheel centre housing diameters |
19.2 mm interior, 34 mm exterior |
| Flywheel thickness |
35.3 mm exterior, 30.65 mm interior |
| Regulator size (W x L x H) |
80 mm x 110 mm x 28 mm |
| Regulator fixation holes |
80 mm centre to centre |
| Regulator wire lengths |
150 mm and 400 mm |
| Regulator wires / plugs / pins |
7 wires, 2 plugs, 7 pins |
| Minimum charging voltage |
14.5 V +/-0.5 V |
| Maximum charging current |
50 A / 500 W |
| Open circuit voltage |
15 V |
| Regulator operating temperature |
-20 C to 85 C |
| Puller thread |
36 mm x 1.5 right hand male |
| Puller dimensions |
60 mm long, 47 mm exterior diameter, 20 mm interior diameter, 37 mm centre housing |
Vehicle Fitment Guide
| Make & Model |
Years |
| Aprilia RSV4 |
2009-2020 |
| Aprilia Tuono V4 |
2011-2020 |
OEM Part Number Cross Reference
Aftermarket replacement. OEM part numbers are listed for reference only.
| Part Number |
Manufacturer / Brand |
| 2D000049 |
Aprilia - stator and flywheel |
| 1A010574 |
Aprilia - stator and flywheel |
| 897479 |
Aprilia - stator |
| B043488 |
Aprilia - voltage regulator |
| 020913Y |
Aprilia - flywheel puller |
| RMS050-103753 |
RMSTATOR - crankcase cover gasket |
Frequently Asked Questions
Does this kit fit without modification?
Yes. Every part in the kit is dimensioned to replace the original units on the listed Aprilia RSV4 and Tuono V4 models, so no cutting, drilling or rewiring is required. Please confirm the OEM part numbers on your original stator, flywheel and regulator against the cross reference table before ordering.
What is included in the kit?
A heavy-duty Kokusan recall-type OEM flywheel, a triple-tested heavy-duty stator, a voltage regulator rectifier, a crankcase cover gasket and a flywheel puller.
How do I know my charging system has failed?
Typical signs are a battery that will not hold charge, dimming lights at higher revs, a charging voltage that stays below 14.5 V at the battery terminals, or a stator that reads well away from 0.3 ohms +/-20% yellow to yellow. Discoloured or blackened stator windings and a flywheel with flaking epoxy around the magnets are visual confirmation.
Why does the replacement flywheel use weaker magnets?
The original Aprilia flywheels used excessively strong magnets. That produced far more charging output than the motorcycle needs, and the surplus energy is dissipated as heat inside the stator until the windings burn out. The Kokusan flywheel supplied here uses lower strength magnets so the output is matched to the bike's electrical demand and the stator runs cooler.
Dispatched from the UK · 12-month warranty · Fitment support from our technical team
