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The 300 Watt Ariel Square Four Alternator conversion

It’s an age old problem for the enthusiastic Ariel Square Four owner. The lights go on and the original dynamo struggles to keep the battery charged. As the battery discharges the ignition system struggles to generate a healthy spark and the engine starts to misfire.

Ariel Square Four 300 Alternator

Ariel Square Four 300 Alternator

Based on quality Nippon Denso internals this conversion replaces the original dynamo with no modifications to original engine casings. Fitting can be accomplished in a morning and the built in regulator and rectifier make wiring an easy task.

Proven worldwide to be ultra reliable and in the words of one discerning German customer “Plug & Play” This is the must have modification for the Ariel Square Four. It will transform the riding experience.

Lower kick in speeds mean the alternator will balance the charge of the ignition system and modern 12v headlamp bulb at around 25mph*

* Depends on exact primary and final drive gearing.

Full fitting kit and instructions supplied

More questions? The links below will let you download copies of the mechanical and electrical fitting instructions supplied with the units.

Ariel SQ4 alternator wiring instructions
Ariel SQ4 mechanical fitting instructions

Precision CNC components hand assembled and tested

The Ariel Square Four alternators are produced in small batches. The re-cycled components from the donor Nippon Denso alternators are cleaned and checked both mechanically and electrically.

All the components used in the conversion are precision items produced using CNC facilities. Final hand assembly and testing take place in our workshops.

A custom built test rig runs each alternator under load so that we can confirm correct output and regulation. Before dispatch each unit is allocated a serial number and details are recorded to ensure trace-ability in the event of future service being required.

Buying an Ariel Sq4 Alternator

To order an alternator please contact me directly via email: bennet@ironhorsespares.co.uk

The Ariel Square Four Alternators are exclusive and built to order and can use some donor components from your old dynamo to keep the price down. All alternators include the following:

  • Alternator 300 watt output with built in regulator and rectifier.

  • Complete fitting kit including electrical components required.

  • Detailed fitting and wiring instructions.

  • New dynamo gear (new matching distributor gears are also available)

A complete kit costs £635.00 however if you supply donor components as follows the price is reduced:

Supply your own drive gear housing:  £85 discount
Supply your own dynamo skew gear:  £45 discount