MSD ASY12728 Flying Magnet Crank Trigger Wheel Mopar B/RB-Series 7.3125 in. Red

The MSD ASY12728 is a Flying Magnet Crank Trigger Wheel designed for Mopar B and RB-Series engines with a 7.3125-inch harmonic balancer. This is the trigger wheel component sourced from MSD Kit #8636, machined from 6061-T6 billet aluminum and finished in MSD's signature red anodize for corrosion resistance and durability.

Stable ignition timing is critical in high-horsepower, high-cylinder-pressure applications. Unlike distributor-based systems that are subject to timing errors introduced by chain stretch, gear lash, and mechanical flex, a crank trigger reads directly from the crankshaft — the most stable rotating component in the engine — delivering a precise and repeatable trigger signal at every RPM.

MSD Flying Magnet Technology:

• Four rare-earth magnets are pressed and riveted directly into the trigger wheel — eliminating the steel studs used by traditional designs
• A stationary non-magnetic pickup is triggered only when a magnet passes — track debris, vibration, and stray bolts cannot cause false triggers
• Magnets are the sole trigger source, making this the most reliable and accurate crank trigger design available
• Trigger wheel is machined from 6061-T6 aluminum and red anodized for strength and durability at extreme RPM
• Designed for use with CNC-machined aluminum sensor brackets featuring long adjustment slots for precise timing adjustment (brackets sold separately or included in full kit)

Kit Contents (Wheel Only — from Kit #8636):

• Flying magnet trigger wheel (7.3125 in. balancer diameter)

Important Notes:

• This listing is for the trigger wheel only as sourced from MSD Kit #8636 — brackets, pickup, and hardware are not included
• Must be used with an MSD 6, 7, or 8-Series Ignition Control
• A locked-out distributor is required when using a crank trigger system
• Compatible with Mopar B and RB-Series big block engines with a 7.3125-inch harmonic balancer