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Stator + Kokusan Flywheel + Puller Kit (RMS900-103880)

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  • Regular price $969.99
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Recall-Type Stator + Kokusan Flywheel Rotor + Gasket + Puller for Aprilia 2009–2020 RSV4 and 2011–2020 Tuono V4 – Replacement Part No. 2D000049 / 897479

Introducing the latest heavy-duty recall-type charging system upgrade kit for Aprilia 2009–2020 RSV4 and 2011–2020 Tuono V4 models.

Anyone who rides or repairs Aprilia motorcycles is probably familiar with the stator, flywheel and voltage regulator issues common to these models. Many of these bikes experience at least one stator failure during their lifetime. The main issue was the use of extremely strong magnets in the original flywheels, which produced very high stator output and excessive heat. This often resulted in burned or shorted stator windings and, in many cases, a failed voltage regulator.

The solution was a new Kokusan flywheel with lower-strength magnets, reducing stator output and heat generation. This produces charging system output better matched to the bike's electrical requirements and helps improve the long-term reliability of the stator and voltage regulator.

To prevent or correct these flywheel problems, the engineers at RMS Labs developed a complete, heavy-duty charging system replacement kit for Aprilia. Upgrade your charging system today.

Included in this Kit:

  • Heavy-duty Kokusan recall-type OEM flywheel
  • Triple-tested heavy-duty stator
  • Voltage regulator rectifier
  • Crankcase cover gasket
  • Flywheel puller

This kit allows you to upgrade the failure-prone charging system with a heavy-duty version using the latest technologies.

Features:

  • Kokusan upgrade/recall-type flywheel: Lower-strength magnets provide correct stator output, reduced heat generation and improved long-term reliability.
  • Built to OEM size: Designed for a precise fit and straightforward installation.
  • Improved epoxy: Uses high-temperature epoxy that is stronger than OEM epoxy, reducing the risk of magnet detachment.
  • High-grade steel capping: Helps prevent harsh additives in motor oil from degrading the epoxy securing the magnets. If a magnet comes loose, the sleeve is designed to prevent it from contacting the stator.
  • Precise balancing: Helps eliminate crankshaft vibrations for improved engine longevity.

Before Installing the New Stator:

  • Check the AC output of the stator.
  • Replace any burned or corroded connectors on the stator and regulator rectifier.
  • Check and repair any melted wiring.
  • Use high-temperature dielectric grease on all connectors.

The stator may use a different wire colour code from the original. All wires are installed in the correct order; do not change any wiring configurations. This stator is designed as a direct plug-in replacement and should be used as such.

When bolting the stator in place, always use locking compound. If the stator includes a pickup coil, ensure the air gap is correct during installation. We recommend setting it as close as possible, but no less than 0.010 inches.

Before Installing the New Voltage Regulator Rectifier:

  • Check the AC output of the stator.
  • Replace any burned or corroded connectors on the stator and regulator rectifier.
  • Check and repair any melted wiring.
  • Use high-temperature dielectric grease on all connectors.

Flywheel Installation:

Before attempting to start the Aprilia, adjusting the air gap is necessary. Rotate the flywheel until the raised node is aligned with the pickup/pulser coil. Adjust the gap as close as possible, but no less than 0.010 inches.

Flywheel Puller:

Removing a Powersport Vehicle's Flywheel / Rotor

How It Works

Flywheel pullers are versatile engine service tools and are essential in every toolbox. A wide selection of rotor and flywheel pullers is available to fit many motorcycles and ATVs. They are simple to use, typically consisting of an outer body that holds the flywheel and a screw that pushes against the crankshaft. Some designs are even simpler, using only a bolt that threads into the flywheel. A taper holds the flywheel or rotor and crankshaft together, while the fixing bolt secures the flywheel to the shaft through applied torque.

An Important Component to Use

Many flywheel or rotor pullers include a small cap. This is a crankshaft thread protector and should always be used when supplied. Fit the cap onto the end of the inner piece of the puller, which presses against the tip of the crankshaft. This protects the fine threads from being stripped or damaged during flywheel or rotor removal.

Actions to Avoid

Removing a flywheel or rotor is usually straightforward. However, corrosion, over-torquing the fixing bolt or repeated heat cycles can make removal difficult. Using a larger breaker bar or air impact tools to force the flywheel off can damage the flywheel, puller or crankshaft. Avoid these methods to prevent costly damage.

Tips for Releasing a Stuck Flywheel:

Torque Wrench

To check whether the flywheel is stuck, set the torque wrench to 50 ft-lbs and try to ease the flywheel off. If it is not stuck, you should be able to remove it with less torque. If it is stuck, do not apply more torque, as this could break the wrench.

Ball Peen Hammer

If 50 ft-lbs does not release the flywheel, use a 12 or 16 oz ball peen hammer. Strike the end of the flywheel puller with a medium blow. The impact may release the flywheel. Be prepared to catch it, as the shock can cause it to jump off. Always wear safety glasses.

Propane Torch

If the hammer does not work, heat may be used as a last resort. The heat should expand the flywheel without expanding the crankshaft as quickly, helping loosen the flywheel.

Important Safety Tips: To avoid setting fire to the garage, vehicle or yourself, take the following precautions before heating the flywheel:

  • Clean any oil or flammable liquids from the flywheel.
  • Ensure the work area is free of flammable liquids and is well ventilated.
  • Remove the gas tank and place it at a safe distance.

Focus the torch flame and heat only the centre of the flywheel. Some flywheels use adhesive or other compounds to secure the magnets in the rim, and concentrated heat can damage these materials. Be prepared to catch the flywheel if it comes off the crankshaft. Remember that it will be hot and take precautions to avoid burns.

With these tips and techniques, you can handle a stuck flywheel without damaging the puller or surrounding components.

Warning:

Risk of electric shock. Disconnect the battery before servicing.
Ensure proper installation by a qualified technician to avoid malfunction.

Stator Dimensions:

  • Interior diameter: 43 mm
  • Exterior diameter: 105 mm
  • Thickness: 13.8 mm
  • Length of wires from stator to grommet: 125 mm
  • Length of wires from grommet to plug: 320 mm

Stator Specifications:

  • Number of wires: 3
  • Number of plugs: 1
  • Number of pins: 3

Wire-to-Wire Resistance:

  • Alternator: Between each Yellow = 0.3 ohms ±20%

Flywheel Dimensions:

  • Exterior diameter: 121 mm
  • Interior diameter: 107 mm
  • Interior diameter of centre housing: 19 mm
  • Exterior diameter of centre housing: 34 mm
  • Exterior thickness: 35.3 mm
  • Interior thickness: 31.65 mm

Flywheel Puller Specifications:

  • Thread: 36 mm x 1.5 right-hand male
  • Length: 60 mm
  • Exterior diameter: 48 mm
  • Interior diameter: 35 mm
  • Exterior diameter of centre housing: 37 mm