FATJOHNSON 3085639 Cdi Module Atv 886852637829 499CC

( Brand: Fatjohnson ), ( Manufacturer Part Number: 3085639 ), ( Placement On Vehicle: Rear ), ( Fits: For Polaris Atv Sportsman 500 6x6 ), ( Type: Cdi Module Box ), ( UPC: 886852637829 )

Review FATJOHNSON Cdi Module Polaris 499cc Atv New fits SPORTSMAN 500 1996–2000

The **Fat Johnson 886852637829 CDI Module** is a high-performance ignition upgrade designed specifically for the **Polaris Sportsman 500/499cc ATV models from 1996 through 2000**, ensuring a dramatic improvement in throttle response, power delivery, and overall engine efficiency. This aftermarket component replaces the stock CDI (Capacitor Discharge Ignition) unit, which is responsible for generating the precise electrical spark needed to ignite the air-fuel mixture in the engine s combustion chamber. Engineered with advanced circuitry and a robust construction, the Fat Johnson module delivers a stronger, more consistent spark, reducing misfires, improving cold-start reliability, and enhancing acceleration especially under heavy loads or during aggressive riding conditions. The upgraded module also helps mitigate issues common in older Polaris engines, such as inconsistent spark timing, which can lead to rough idling, hesitation, or even engine stalling. Whether you re tackling rough terrain, towing heavy loads, or simply seeking a more responsive ride, this CDI module provides a noticeable boost in performance while maintaining compatibility with the stock wiring harness, making installation straightforward for even DIY enthusiasts. Built to withstand the demands of off-road use, the Fat Johnson module is a durable, long-lasting solution that complements other performance upgrades, such as high-performance air filters, exhaust systems, or carburetor kits, to further optimize your Sportsman s power output. Ideal for riders who demand reliability and performance from their ATV, this module is a proven upgrade that bridges the gap between stock limitations and high-end aftermarket tuning.

### **Pros and Cons of Buying a Fat Johnson 886852637829 CDI Module for a Polaris Sportsman 500/499cc (1996 2000)**

1. **Compatibility** The Fat Johnson CDI module is designed specifically for Polaris Sportsman models from the late 1990s, ensuring a proper fit without major modifications.

2. **Reliability** Fat Johnson is a well-known brand in the ATV and motorcycle ignition system market, offering durable and high-quality components that reduce the risk of electrical failures.

3. **Improved Ignition Performance** Many owners report better spark consistency, smoother starts, and reduced misfires compared to the stock CDI, which can degrade over time.

4. **Ease of Installation** The module is designed for straightforward replacement, requiring minimal wiring adjustments and no major mechanical changes.

5. **Cost-Effective Upgrade** Compared to full engine rebuilds or new ignition coils, this is a relatively inexpensive way to restore or enhance ignition performance.

6. **Aftermarket Support** Fat Johnson parts are widely available through ATV specialty shops, online retailers, and eBay, making replacements easy to source.

7. **Potential Longevity Boost** A failing CDI can damage other components (like spark plugs or coils) over time. Replacing it early may prevent further wear on the engine.

1. **Cost** While not extremely expensive, a new CDI module (around $50 $100 depending on source) is still an additional expense if the original is still functional but failing intermittently.

2. **Mixed Owner Experiences** Some users report no noticeable improvement, especially if the issue stems from other parts (e.g., spark plugs, wires, or fuel system problems).

3. **Potential for Counterfeit Parts** Purchasing from untrusted sellers (e.g., eBay without seller ratings or Amazon third-party vendors) could result in knockoffs that fail prematurely.

4. **Wiring Concerns** If the original wiring harness is damaged or corroded, simply replacing the CDI may not solve the problem additional diagnostics may be needed.

5. **Limited Warranty** Unless purchased from an authorized dealer, warranties may be minimal or nonexistent, leaving you responsible for failures.

6. **Not a Cure-All** If the engine has other issues (e.g., carburetor problems, low compression, or a failing alternator), replacing the CDI alone won t fix those problems.

---

### **Conclusion**

The **Fat Johnson 886852637829 CDI module is a solid upgrade for a Polaris Sportsman 500/499cc from 1996 2000**, particularly if you re experiencing intermittent misfires, hard starts, or electrical ignition failures. It s a **low-risk, high-reward** fix for ignition-related issues, with minimal installation effort. However, it s not a universal solution if the problem persists after replacement, further diagnostics (e.g., checking spark plugs, wires, or fuel delivery) are warranted.

If your current CDI is **consistently failing** or showing signs of wear (e.g., weak spark, erratic performance), replacing it with a Fat Johnson module is a **strong recommendation**. If the issue is **intermittent or minor**, testing the original CDI with a multimeter or consulting a mechanic first may save unnecessary costs.

---

1. **Verify the Problem** Before purchasing, confirm that the CDI is indeed the culprit (e.g., test with a known-good module or check for voltage output).

2. **Buy from a Trusted Source** Purchase directly from **Fat Johnson s official website, reputable ATV parts dealers, or well-reviewed online retailers** to avoid counterfeit parts.

3. **Inspect Wiring & Connections** Ensure the wiring harness and terminals are clean and free of corrosion before installing the new module.

4. **Consider a Full Ignition System Check** If issues persist after replacement, evaluate other components (spark plugs, coil, wires, carburetor).

5. **Proceed with Installation** If confident in the diagnosis, the upgrade is straightforward and offers a good return on investment for improved reliability.

**Final Verdict:** *Worth the upgrade if ignition problems are confirmed, but not a magic fix for all engine issues.*

Details:

3085639 3084691 CDI BOX. Any direct return of purchased items will not be processed. Polaris Sportsman 335 Carb 1999 - 2000. CDI MODULE BOX For POLARIS ATV SPORTSMAN 500 6X6 RSE DUSE 495853 3086982 3085564.

Polaris Sportsman 400 4x4 Carb 2001 -2002.

specifications electricacompone:

• for models: 500, Sportsman
• for makes: Polaris
• for years: 1996-2000
• brand: Fatjohnson
• mpn: 3085639
• placement on vehicle: Rear
• fits: For Polaris Atv Sportsman 500 6x6
• type: Cdi Module Box
• upc: 886852637829

offer electricacompone:

• best offers: True
• availability: In Stock
• options: Ship-to-home
• started: June 5, 2026
• sold: 0

general electricacompone:

• condition: New
• ATV, Side-by-Side UTV Parts Accessories > Electrical Ignition Components > Other Electrical Ignition Components

seller electricacompone:

• rating: 97.8%
• # reviews: 3290
• city: Hebron, Kentucky

shipping electricacompone:

• class: Standard
• type: Fixed
• cost: $0.00
• transit: 5-11 Days
• service: Standard

returns electricacompone:

• time: 30 Days
• policy: Returns Accepted
• paid by: Seller

payments electricacompone:

• other
• wallet: Google-pay
• credit card: Visa

Fatjohnson 3085639 Is Similar To:

• Fatjohnson 686558921853 Speed Sensor Fits For Polaris Rzr Ranger 500 570 800 900 1000 Xp Etx Ev Turbo (49% similar) 2015 -2016 ranger etc. For ranger etc 2015 -2016 Eva 2015 -2017. 3234299 3234508 speed sensor: 1 high-quality aftermarket. 2012 -2017 Zr 570 all...(November 14th, 2025)
• Fatjohnson 641376582501 Ignition Switch With 2 Keys For 2011-2017 Polaris Sportsman 500 570 700 800 850 (52.5% similar) 2008 sportsman 6X6. 2008 sportsman touring 500 efi. 2008 sportsman 500 ho efi. Any direct return of purchased items will not be processed. 2008 sportsman 800 ho efi...(April 2nd, 2026)
• Fatjohnson 641376587094 Starter Solenoid Relay For Suzuki Katana Gsx 600 F 750 1988-1997 31800-33400 (47.2% similar) Any direct return of purchased items will not be processed. For Suzuki LS650 solenoid relay. For Suzuki motorcycle. Please compare the part number with your original one before purchasing. Relay fit Suzuki LS650 1995 -2017 1986 - 1988 LS650F 1988 -1990 LS650P 1986 -90. 1 x starter solenoid ...(April 25th, 2026)