5/20/21:  Doing evaluation on the revised designs.  Dyno testing & some grass-runs scheduled with prototypes in process.  So far have had good results on the 77RV testing we’ve been running for our development.

We are planning to have a revised design PolarFireplug CDI available sometime this summer.






Contact us by E-mail (e-mail for quickest reply)

or by Phone: (810) 765-0820 (EST, limited phone availability) to confirm coil availability

Includes 2 New Coils (limited to coil stock availability)
Mounts in original factory location with original connectors
Includes a separate Kill-Switch wire for common 2-wire tether switch connection (ground the wire through tether or kill-sw to stop spark).


  • 1973~1975 TNT-F/A & 75 Everest
  • 1975 RV245
  • 1976 RV250 & RV340 (RV345)
  • 1977 RV340
  • 1978 RV/Sonic models that use PolarFire CDI

Please understand we will not use OLD / USED OEM-coils
since failure issues can occur beyond our control.

NOTE: HewTech Electronics LLC cannot warranty the individual coils used in the ROTAX FIREPLUG CDI. We purchase these parts from PARTS-UNLIMITED, and test them prior to installation. We have absolutely no control over their quality or workmanship to warranty them. PARTS-UNLIMITED does not offer ANY warranty on electrical parts, therefore HewTech Electronics LLC cannot extend our warranty to cover the external coils. If a coil is found to have failed, HewTech Electronics LLC will warranty the labor at no cost to replace a coil, however cost of the coil & shipping is the responsibility of the CDI owner, and not HewTech Electronics LLC.

Uses original Factory 3-wire AND any standard 2-wire kill-switch!

Contact us by e-mail or telephone for our shipping address (both listed below) if sending payment or new coils.

HewTech Electronics is offering A POLARFIRE Replacement FIREPLUG CDI for the 73~77 Ski-Doo & Moto-Ski’s ignitions (Replaces CDI 1-217-280-017 & 1-217-280-044) models only.

We built a prototype that included all the FIREPLUG CDI improvements we learned over the years and sent it out for dyno-testing and evaluation. Our efforts paid off. We now have a PolarFire replacement FIREPLUG CDI that follows the OEM timing exactly. We also match the OEM wiring connectors & mounting holes, so no timing adjustment, no wiring & no holes to drill. Just bolt on & GO with FIREPLUG reliability and performance!


Verify that the chassis to engine (bonding) wire is connected & in good condition. Without this wire connection, the FIREPLUG CDI may not spark or operate correctly.

NOTE: The stock CDI may operate without this bonding wire, since it uses the aluminum case as a common ground. The FIREPLUG CDI case is isolated and no current passes through it, therefore the wire to connect the Chassis to Engine is necessary.

The Brown wire (our Black wire) from the connector grounds to the engine crankcase. This wire often times breaks or corrodes over time. Verify your brown-wire does connect to engine ground coming from your engine, through the harness to the CDI.

Disconnect kill-switch harness, often times the kill switch & key-switch fail & short out the CDI box.

Verify Stator & Trigger resistance: ~315 ohm Stator (RED to Brown) & 55~60-ohm triggers (striped wires).

Additional information

Weight 2 lbs