Compufire 40A 3 Phase Charging System - 40 AMP Vented Rotor `1981-1999 BT — Harley-Davidson (1981-1999)

Compufire 40A 3-phase charging system with vented rotor for 1981–1999 Harley-Davidson Big Twin models. Produces 25 amps at idle and peaks at 40 amps above 2,800 rpm, with a vented rotor design that dissipates heat and keeps the stator running cooler for sustained high output.

Features

• 25 AMP output at idle, 40 AMP above 2800 rpm
• Vented rotor for improved heat dissipation
• High-output voltage regulator at 14.25 V from idle
• Fits Softail, Dyna, and FLT with OEM primary due to narrow rotor and stator profile
• Made in the USA

Specifications

• Brand: Compufire
• Manufacturer Part #: 55560
• UPC: 694342548056
• Length: 9 in
• Width: 8 in
• Height: 8 in
• Weight: 11 lbs

Fitment

Fits Harley-Davidson Softail, Dyna, and FLT models from 1981 to 1999 equipped with OEM primary. The narrow rotor and stator profile are designed for direct compatibility with stock primary cases.

Frequently Asked Questions

What amp output does this system produce?

25 amps at idle and 40 amps above 2,800 rpm. This higher output keeps your battery charged during highway riding and accessories use.

Will this fit my 2000+ Harley Big Twin?

No — this system is designed for 1981-1999 models. Newer Big Twins require updated charging systems.

Can I use this with an aftermarket primary?

This system is designed for OEM primary cases due to the narrow rotor and stator profile. Verify fitment before ordering if you have a non-stock primary.

How does the vented rotor help performance?

The vented rotor design dissipates heat more efficiently, keeping the stator cooler and allowing the system to maintain maximum output for longer periods.