Dirt Bike Engine Gaskets and Kits
Dirt Bike Engine Gaskets & Top-End Kits for Yamaha, Honda XR650L & CRF at JJ Motorsports
Refresh your dirt bike's top end with premium engine gaskets and complete kits from JJ Motorsports, precision-manufactured for leak-free sealing, optimal compression, and reliable performance in motocross, enduro, and trail riding. Our selection includes full gasket sets, top-end rebuild kits, O-rings, and head/base gaskets designed for perfect fitment, heat resistance, and easy installation without machining. Compatible with popular models like Yamaha YZ/WR, Honda XR650L, CRF, and more, these high-quality components from trusted brands ensure smoother operation, reduced oil consumption, and extended engine life under dusty, high-RPM conditions. From Moose Racing's comprehensive off-road sets to ProX and Athena's OEM-spec top-end kits, get everything needed for a professional rebuild—head gaskets, valve seals, base gaskets, and more—to restore power and prevent blow-by on every ride.
Shop brands like Moose Racing, ProX, and Athena for race-proven quality. Explore related categories such as dirt bike piston and ring kits for full rebuilds or dirt bike engine for cylinders and valves.
Top Dirt Bike Engine Gaskets & Kits
- Moose Offroad Complete Gasket Set Yamaha 8080037MSE – Full engine gasket kit for Yamaha models; includes all necessary seals, O-rings, and gaskets for complete top-to-bottom rebuild with OEM reliability.
- ProX Top End Gasket Set Honda XR650L 35.1623 – Precision top-end kit for Honda XR650L; features head, base, and valve stem seals for leak-free compression and easy installation.
- Athena Top End Gasket Kit Honda P400210600323 – High-performance top-end rebuild kit for Honda CRF models; includes multi-layer steel head gasket, O-rings, and seals for maximum sealing under extreme conditions.
Browse our in-stock inventory below with same-day shipping and expert support. Free shipping on orders over $99! Questions? Contact us for fitment advice!
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On Sale
COMETIC Top End Gasket Kit - 84 mm - Suzuki C3410-EST
COMETIC
MSRP: $69.95Now: $66.00Was: $69.95A compromised top-end gasket kit leads to compression loss, coolant seepage, and catastrophic engine failure. Cometic's EST gasket kit delivers the sealing integrity and thermal management your high-output engine demands, whether you're running naturally...09347837- SKU:
- 09347837
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $69.95Now: $66.00Was: $69.95 -
On Sale
COMETIC Top End Gasket Kit - 97 mm - Yamaha C3540-EST
COMETIC
MSRP: $68.95Now: $65.00Was: $68.95A top-end gasket kit failure can compromise your engine's seal integrity and cost you horsepower—especially in high-boost or naturally aspirated applications pushing cylinder pressures to the limit. Cometic's EST (Extreme Sealing Technology) design uses...09347839- SKU:
- 09347839
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $68.95Now: $65.00Was: $68.95 -
On Sale
COMETIC Top End Gasket Kit - 52.5 mm - Kawasaki C3542
COMETIC
MSRP: $31.95Now: $30.00Was: $31.95A compromised top-end seal means lost compression, oil weeping, and catastrophic engine failure—especially under high boost or sustained high RPM. The COMETIC C3542 gasket kit eliminates these risks with MLS (multi-layered steel) construction and EST...09347840- SKU:
- 09347840
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
MSRP: $31.95Now: $30.00Was: $31.95 -
On Sale
COMETIC Top End Gasket Kit - 88 mm - KTM C3605-EST
COMETIC
MSRP: $74.95Now: $70.00Was: $74.95A failing top-end gasket kit compromises cylinder pressure, reduces power output, and risks catastrophic engine damage. The COMETIC C3605-EST delivers the sealing reliability you need for high-horsepower 4-stroke engines, whether naturally aspirated or...09347843- SKU:
- 09347843
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
MSRP: $74.95Now: $70.00Was: $74.95 -
On Sale
COMETIC Top End Gasket Kit - 96 mm - Honda C3621
COMETIC
MSRP: $85.95Now: $81.00Was: $85.95A failing top end gasket compromises combustion seal integrity, leading to lost compression, oil leakage, and costly engine damage. The COMETIC C3621 kit delivers the precision sealing your high-output engine demands, whether you're running naturally...09347844- SKU:
- 09347844
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $85.95Now: $81.00Was: $85.95 -
On Sale
COMETIC Top End Gasket Kit - 97 mm - Yamaha C3630
COMETIC
MSRP: $53.95Now: $51.00Was: $53.95A failing top end gasket can cost you races, reliability, and engine integrity. This Cometic gasket kit delivers the sealing performance required for high-output 4-stroke engines—whether naturally aspirated or boosted—using multi-layered steel...09347845- SKU:
- 09347845
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $53.95Now: $51.00Was: $53.95 -
On Sale
COMETIC Top End Gasket Kit - 77 mm - Yamaha C3695
COMETIC
MSRP: $79.95Now: $75.00Was: $79.95A failing head gasket doesn't just cost you power—it costs you reliability. The COMETIC Top End Gasket Kit ensures a proper seal under high combustion pressures, whether you're running naturally aspirated or forced induction. With multi-layered steel...09347847- SKU:
- 09347847
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $79.95Now: $75.00Was: $79.95 -
On Sale
COMETIC Top End Gasket Kit/O-Ring Cylinder Head Gasket - Yamaha C3731
COMETIC
MSRP: $39.95Now: $38.00Was: $39.95A top-end gasket kit is essential for any cylinder head removal or rebuild—whether you're performing routine maintenance or a complete engine overhaul. Using OEM-equivalent seals ensures proper compression, prevents oil and coolant leaks, and maintains...09347849- SKU:
- 09347849
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
MSRP: $39.95Now: $38.00Was: $39.95 -
On Sale
COMETIC Top End Gasket Kit - 82 mm - Honda C3735
COMETIC
MSRP: $67.95Now: $64.00Was: $67.95A top-end rebuild demands gasket integrity that matches your engine's output. Cometic's MLS head gaskets and EST technology eliminate hot spots and bore distortion, ensuring consistent sealing under high cylinder pressures—whether naturally aspirated or...09347851- SKU:
- 09347851
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
MSRP: $67.95Now: $64.00Was: $67.95 -
On Sale
COMETIC Top End Gasket Kit - KTM/Husqvarna C3808
COMETIC
MSRP: $92.95Now: $87.00Was: $92.95A failing head gasket means catastrophic engine damage and downtime you can't afford. The COMETIC C3808 top end gasket kit delivers the sealing integrity and thermal stability required to handle today's high-output 4-stroke engines—whether naturally...09347802- SKU:
- 09347802
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $92.95Now: $87.00Was: $92.95 -
On Sale
COMETIC Top End Gasket Kit - 90 mm - KTM C3779-EST
COMETIC
MSRP: $74.95Now: $70.00Was: $74.95A quality top end gasket kit is non-negotiable when you're rebuilding or maintaining a high-output 4-stroke engine. Cometic's EST technology delivers superior sealing integrity under extreme combustion pressures, preventing blow-by and power loss that...09347853- SKU:
- 09347853
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
MSRP: $74.95Now: $70.00Was: $74.95 -
On Sale
COMETIC Top End Gasket Kit - KTM/Husqvarna/Gas Gas C3623
COMETIC
MSRP: $46.95Now: $44.00Was: $46.95A top-end rebuild demands precision gasket sealing to contain combustion pressures and maintain ring seal—especially in high-output 4-stroke engines where even minor leakage degrades performance and reliability. The COMETIC C3623 kit delivers the exact...09347804- SKU:
- 09347804
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
MSRP: $46.95Now: $44.00Was: $46.95 -
On Sale
COMETIC Top End Gasket Kit - 79 mm - KTM/Husqvarna/Gas Gas C3595-EST
COMETIC
MSRP: $87.95Now: $83.00Was: $87.95A top-end gasket failure can sideline your bike mid-season, and inferior gaskets invite compression loss, oil leaks, and catastrophic engine damage. The COMETIC EST gasket kit eliminates guesswork with precision-engineered sealing surfaces and...09347806- SKU:
- 09347806
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
MSRP: $87.95Now: $83.00Was: $87.95 -
On Sale
COMETIC Top End Gasket Kit - 90 mm - KTM/Husqvarna/Gas Gas C3790
COMETIC
MSRP: $97.95Now: $92.00Was: $97.95A worn or failing top-end gasket kit compromises combustion sealing and invites coolant or oil leakage—both costly problems for high-performance engines. The COMETIC C3790 kit delivers the precision engineering needed to maintain peak cylinder pressure...09347857- SKU:
- 09347857
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $97.95Now: $92.00Was: $97.95 -
On Sale
COMETIC Top End Gasket Kit - Kawasaki C3803
COMETIC
MSRP: $84.95Now: $80.00Was: $84.95A failing top end gasket compromises cylinder pressure, bleeds horsepower, and risks catastrophic engine damage—especially in high-output 4-stroke engines running forced induction or extreme naturally aspirated configurations. The COMETIC C3803 Top End...09347860- SKU:
- 09347860
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $84.95Now: $80.00Was: $84.95 -
On Sale
COMETIC Top End Gasket Kit - 96 mm - Kawasaki C3806
COMETIC
MSRP: $88.95Now: $84.00Was: $88.95A quality gasket kit is non-negotiable for any top-end rebuild—it's the barrier between combustion pressures and coolant passages, and failure means catastrophic engine damage. The COMETIC C3806 uses multi-layered steel construction with Viton rubber...09347861- SKU:
- 09347861
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $88.95Now: $84.00Was: $88.95 -
On Sale
COMETIC Top End Gasket Kit - 48 mm - Kawasaki/Suzuki C7737
COMETIC
MSRP: $28.95Now: $27.00Was: $28.95A failing top end gasket compromises combustion chamber sealing, causing power loss, coolant leakage, and potential engine damage. The COMETIC C7737 kit delivers OEM-spec sealing with multi-layered steel construction and Viton rubber coating, engineered...09347867- SKU:
- 09347867
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
MSRP: $28.95Now: $27.00Was: $28.95 -
On Sale
COMETIC Top End Gasket Kit - 54.5 mm - Kawasaki C3543
COMETIC
MSRP: $31.95Now: $30.00Was: $31.95A quality top end gasket kit is critical to maintaining compression, preventing coolant and oil leaks, and ensuring reliable performance during high-output operation. The COMETIC C3543 is engineered specifically for Kawasaki applications with...09347841- SKU:
- 09347841
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
MSRP: $31.95Now: $30.00Was: $31.95 -
On Sale
COMETIC Top End Gasket Kit - 77 mm - Yamaha C3549-EST
COMETIC
MSRP: $74.95Now: $70.00Was: $74.95A failing top end gasket compromises compression, kills power, and leaves you stranded. Cometic's EST gasket kit seals high-output 4-stroke engines reliably, whether naturally aspirated or boosted, by distributing heat evenly across the sealing surface...09347842- SKU:
- 09347842
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $74.95Now: $70.00Was: $74.95 -
On Sale
COMETIC Top End Gasket Kit - 96 mm - Kawasaki C3696
COMETIC
MSRP: $85.95Now: $81.00Was: $85.95A failed head gasket means downtime and expensive engine damage—especially on high-output 4-stroke engines running elevated cylinder pressures. The COMETIC Top End Gasket Kit delivers the sealing integrity your engine demands, with multi-layered steel...09347848- SKU:
- 09347848
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
MSRP: $85.95Now: $81.00Was: $85.95
