FIREPLUG CDI for 1972 Polaris ATX 335 and up to 1977 TX twins.
We originally designed this CDI for the 72-ATX, but found it also works as the replacement for the TX, up to 1977. We have more than a few running on 72-77 Polaris Twins since introduction
Replaces: CU11-KOKUSAN-DENKI CDI / Polaris # #3081305
Tested exclusively on multiple ATX335 (1972) sleds & some TX340 as well as the 73-TX400.
Compatible with factory mounting location & wiring harness for plug-in installation.
DESIGN BACKGROUND: After the release of the TXL CDI, there were a few calls for the 72-ATX CDI. Although a rare, we had calls for 3 the same week. With cooperation from the sled owners a replacement FIREPLUG CDI was developed. These early CDI’s were “STRAIGHT-TIMING”, or basically no ignition curve over the RPM range from the OEM. We soon found this CDI also replaces the Kokusan TX CDI up through 1977.
PERFORMANCE: The FIREPLUG CDI is a High-Performance replacement CDI for your Polaris sled. The FIREPLUG CDI provides a higher energy output, that outperforms the stock CDI in reliability and performance. This translates to quicker starting, better throttle response, stronger pull & cleaner burning. The FIREPLUG CDI connects directly to your factory harness.
The FIREPLUG CDI is manufactured using the best industrial-grade components available. The FIREPLUG is not a high-volume / mass-produced imported device. Every CDI unit is manufactured at HewTech Electronics in Michigan, tested and shipped directly to you. It doesn’t exist until after an order is received.
TIPS & SUGGESTIONS FOR PEAK PERFORMANCE USING THE FIREPLUG / POLARIS CDI IGNITION SYSTEM:
Polaris ignitions are notorious for weak spark energy. Typical low-energy issues will show up in missing at high-rpm missing, or not able to achieve the usual upper RPM. Try this:
USE B8ES or B9ES SPARK-PLUGS: Do not use the BR-type resistor plugs. The resistor limits energy to the gap. Doing away with NGK resistor caps and replacing with direct-contact (non-resistor) caps. We have some available upon request. Select copper-core wires (small-engine type, never automotive carbon-core type, as they have too high ohms/ft resistance for small engine ignition systems.
CLOSE THE PLUG GAPS: Ideally, you want as wide of gap as possible, without misfire. Typical for this ignition with race-fuel is 0.019″~0.020″ (~0.5mm) spark-plug gaps.
When extremely cold outside, try a blend of good grade of PREMIUM fuel (non ethanol, like SHELL ULTRA) with your race-fuel. Race-gas is very high octane. The higher the octane, the higher the flash-point. Lower temperatures also increase the flash-point. With the combination of race-fuel and cold temperatures, higher-compression engines requires additional energy to the plugs to fire the fuel. If the fuel takes longer to light up, this is just like retarding your ignition timing. Your engine will be hard starting in cold weather for this reason, since the cold / high-octane fuel is difficult to fire. A fuel-blend will keep things lighting up when they should & it’s like advancing the timing & letting the fuel fire under the cold conditions. Try it & check your jetting! Most engines will like the blend better if compression is not over 160 PSI.