Tech Tip: Installing and Optimising Your Tri-Spark MOSFET Regulator

Upgrading to a MOSFET Voltage Regulator is one of the single best reliability mods you can perform on a classic motorcycle. Unlike older "shunt" style regulators that get incredibly hot, MOSFET technology runs cooler and provides a much more stable voltage output.

To help you get the most out of your upgrade, we’ve compiled the three most common questions our technical team receives during installation.

1. Polarity: Positive or Negative Earth?

One of the most frequent questions we get is: "Will this work with my bike's grounding setup?"

The Answer: Yes. The Tri-Spark MOSFET Regulator is designed for universal polarity. Whether your British classic is wired for positive earth or you have a custom negative earth conversion, this unit will function perfectly. You don’t need a specific model for either setup—one unit does it all.

2. Dealing with Two-Wire Stators

If you open your package and see three wires for the stator connection but your motorcycle only has two, don't worry—you haven't received the wrong part.

The Fix: When fitting the unit to a two-wire stator, simply leave the yellow wire disconnected. * The Process: We recommend trimming the wire back and sealing the end with heat-shrink tubing to keep the installation tidy and moisture-proof. The regulator is "smart" enough to manage the charging load through the remaining two wires without any impact on performance.

3. Wiring the Red and Black Leads

Wiring can be the most intimidating part of an upgrade. For the Tri-Spark Regulator, the mapping is straightforward, but it’s vital to get the connections solid.

The Mapping:

• Red Wire: Connect this directly to Earth (Chassis/Ground).

• Black Wire: Connect this to the Brown wire that was originally connected to your old rectifier.

Support Tip: For the best results, ensure the Red wire is connected to a clean, paint-free area of the frame. A "high-resistance" ground is the #1 cause of charging issues!

Need More Help?

If you’ve followed these steps and are still seeing low charging numbers on your voltmeter, check your stator output and battery health. Our team is always here to help you keep your classic on the road.