Thumbnail Filmstrip of Relay - Points Magneto RPM Rev Limiter Relay Images
This device is intended to do the "heavy lifting" when grounding a points-style magneto for the purposes of limiting engine speed.
In addition to this relay, you'll need an RPM activated switch to activate it and an engine speed signal from a crank trigger pickup. This high-voltage/high-current relay can handle grounding BIG mags when you need it to. Heavy sprung silver contacts ensure reliability and long life. Each of these units is bench tested in-house before it leaves. See the basic schematic in picture #2.
The pigtail included will help you plug into a standard molex plug used on all crank trigger pickups. The green wire is ground from the pickup and the violet wire is the signal. Use this to connect the pickup to your RPM activated switch.
If your magneto is an internal coil (OAC) Vertex, you can use this too! The positive wire would go to the primary side terminal on the mag. Instead of attaching the black wire to the negative coil terminal as shown, just attach it to engine ground.