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Start ShoppingAthena Big Bore Kit Crankshaft - High-Performance Engine Upgrade for Powersports Vehicles
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Description
Elevate your powersports engine's performance with Athena's Big Bore Kit Crankshaft, engineered to deliver unmatched power and reliability for off-road and on-road adventures. This high-performance upgrade is designed to maximize engine output while maintaining durability under extreme conditions.
Key Features
- Increased Displacement: Boosts engine power output for faster acceleration and higher top speeds.
- Reinforced Construction: Durable, precision-machined components withstand high RPMs and heavy use.
- Precision-Balanced Design: Ensures smooth operation and reduces vibration for enhanced rider comfort.
- Universal Compatibility: Fits most powersports engines for easy installation and broad application.
- Long-Lasting Performance: Built to endure harsh environments and prolonged use without degradation.
Why Choose This Product
Whether you're tackling rugged terrain or racing on the track, this Big Bore Kit Crankshaft delivers the power and reliability needed to push your machine's limits. Its advanced engineering ensures optimal performance while minimizing maintenance needs, making it a smart investment for serious riders. Upgrade to Athena's premium crankshaft solution and experience the difference in engine efficiency and overall vehicle performance.
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Elevate your powersports engine's performance with Athena's Big Bore Kit Crankshaft, engineered to deliver unmatched power and reliability for off-road and on-road adventures. This high-performance upgrade is designed to maximize engine output while maintaining durability under extreme conditions.
Key Features
- Increased Displacement: Boosts engine power output for faster acceleration and higher top speeds.
- Reinforced Construction: Durable, precision-machined components withstand high RPMs and heavy use.
- Precision-Balanced Design: Ensures smooth operation and reduces vibration for enhanced rider comfort.
- Universal Compatibility: Fits most powersports engines for easy installation and broad application.
- Long-Lasting Performance: Built to endure harsh environments and prolonged use without degradation.
Why Choose This Product
Whether you're tackling rugged terrain or racing on the track, this Big Bore Kit Crankshaft delivers the power and reliability needed to push your machine's limits. Its advanced engineering ensures optimal performance while minimizing maintenance needs, making it a smart investment for serious riders. Upgrade to Athena's premium crankshaft solution and experience the difference in engine efficiency and overall vehicle performance.
| SKU | GM5DA48C27 |
|---|---|
| MPN | S410130320005 |
| Brand | Athena |
| Category | Engine |
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Featured Review
| Make | Model | Years |
|---|---|---|
| Honda | CRF450R | 2019-2025 |
| Honda | CRF450RX | 2019-2025 |
| Honda | CRF450RL | 2020-2025 |
Frequently Asked Questions
Yes, complete kit includes 98mm forged piston, Nikasil cylinder, crankshaft, bearings, gaskets, O-rings, and circlips.
Yes, significant fueling changes required. EFI bikes need ECU flash; carb bikes need rejetting. Athena recommends their Power Up Kit.
Direct bolt-on for specified models. No case splitting required.
Typically 6-10 hp increase with proper tuning. Torque gains more noticeable across RPM range.
2-year unlimited hour warranty on cylinder and piston when installed by Athena dealer.
Installation Guide
Difficulty
Hard
Est. Time
8 hr 0 min
Tools Required
- Engine stand
- Piston ring compressor
- Torque wrench
- Micrometer
- Crankcase splitter
- Heat gun
- Engine oil
- Athena gasket kit
Pro Tips
- Always replace main bearings with Athena kit
- Use moly paste on piston skirt
- Professional head check recommended
- 30-minute break-in at varied RPM
Common Mistakes to Avoid
- Incorrect piston orientation
- Insufficient cylinder honing
- Overheating bearings during install
- Not breaking in properly
Comparison vs Stock/OEM
Increases displacement from 449cc to 465cc (+3.6%) with forged components vs cast OEM parts
Improvements
- Higher compression (12.7:1 vs 12.2:1)
- 6-10 hp gains with tuning
- Forged crank withstands higher RPM
- Nikasil cylinder better heat dissipation
Considerations
- Requires professional tuning
- More expensive than stock replacement
- Professional installation strongly recommended
Durability & Warranty
Expected Lifespan
200+ hours racing with proper maintenance
Warranty
2 years cylinder/piston (unlimited hours if dealer installed), 1 year crankshaft
Maintenance
Check piston clearance every 50 hours, replace piston at 100 hours racing, use quality semi-synthetic oil
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