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Start ShoppingCOMETIC MLS Big Twin Base Gasket - High-Performance Sealing for Harley-Davidson Engines
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Description
Upgrade your Harley-Davidson engine's reliability with COMETIC's premium MLS base gasket. Engineered for Big Twin/Twin Cam models, this gasket ensures optimal sealing, durability, and long-term performance for riders who demand excellence.
Key Features
- Multi-Layer Steel (MLS) Construction: Superior sealing properties and resistance to heat, oil, and compression for extended service life.
- 0.040" Thickness: Precision-engineered for perfect fit and even pressure distribution across the cylinder base.
- Harley-Davidson Compatibility: Specifically designed for Big Twin/Twin Cam cylinder heads to ensure flawless installation and performance.
- Lightweight Design: Only 0.2 lbs, reducing engine strain while maintaining structural integrity.
Why Choose This Product
COMETIC's MLS gasket delivers unmatched durability and sealing reliability for high-performance engines. Its precise dimensions and premium materials prevent leaks, reduce maintenance, and enhance engine efficiency. Perfect for riders seeking dependable performance without compromising on quality or compatibility with classic Harley-Davidson models.
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Upgrade your Harley-Davidson engine's reliability with COMETIC's premium MLS base gasket. Engineered for Big Twin/Twin Cam models, this gasket ensures optimal sealing, durability, and long-term performance for riders who demand excellence.
Key Features
- Multi-Layer Steel (MLS) Construction: Superior sealing properties and resistance to heat, oil, and compression for extended service life.
- 0.040" Thickness: Precision-engineered for perfect fit and even pressure distribution across the cylinder base.
- Harley-Davidson Compatibility: Specifically designed for Big Twin/Twin Cam cylinder heads to ensure flawless installation and performance.
- Lightweight Design: Only 0.2 lbs, reducing engine strain while maintaining structural integrity.
Why Choose This Product
COMETIC's MLS gasket delivers unmatched durability and sealing reliability for high-performance engines. Its precise dimensions and premium materials prevent leaks, reduce maintenance, and enhance engine efficiency. Perfect for riders seeking dependable performance without compromising on quality or compatibility with classic Harley-Davidson models.| SKU | GM875E2A61 |
|---|---|
| MPN | C9438 |
| UPC/GTIN | 191070024741 |
| Brand | Cometic |
| Category | Gaskets/Seals |
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Featured Review
| Make | Model | Years |
|---|---|---|
| Harley-Davidson | Evo Big Twin | 1986-2017 |
| Harley-Davidson | Twin Cam | 1999-2017 |
Frequently Asked Questions
Yes, C9438 fits all Evo Big Twin and Twin Cam models from 1986-2017 including Softail.
0.040" thickness - matches most stock specs but confirm with your service manual for exact clearance.
Yes, compatible with most big bore kits up to 124" when using Cometic head gaskets.
No, MLS gaskets are designed for dry installation - no RTV or sealant needed.
Installation Guide
Difficulty
Medium
Est. Time
1 hr 0 min
Tools Required
- torque wrench
- socket set
- gasket scraper
- engine oil
- assembly lube
Pro Tips
- Clean cylinder base and case with brake cleaner
- Use torque specs from service manual (typically 15-20 ft-lbs)
- Apply thin layer of assembly lube to cylinder studs
Common Mistakes to Avoid
- Not cleaning mating surfaces thoroughly
- Incorrect torque sequence
- Over-torquing bolts
Comparison vs Stock/OEM
Multi-layer steel vs single-layer composite - superior sealing under high pressure
Improvements
- Better heat resistance
- Improved sealing for high compression
- Longer lifespan under performance conditions
Considerations
- Requires precise torque - not as forgiving as stock composite
Durability & Warranty
Expected Lifespan
Engine life (100,000+ miles typical with proper install)
Warranty
1 year manufacturer defect warranty
Maintenance
Inspect during top-end service; no specific maintenance required
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