Dirt Bike Engine
Dirt Bike Engine Parts at JJ Motorsports
Discover a full range of dirt bike engine components for rebuilding or upgrading your performance from JJ Motorsports. From crankshafts to cylinder heads and piston kits, these precision-engineered components ensure reliable performance. For additional upgrades, check out our full selection of off-road dirt bike parts to keep your engine running at peak efficiency on the track or trails.
Shop trusted brands like Wiseco for forged piston kits and K&N for high-flow oil filters. Explore related categories such as Dirt Bike Air and Fuel for intake upgrades or Dirt Bike Exhaust for complete systems.
Browse our in-stock inventory below with same-day shipping and expert support. Questions? Contact us for fitment advice!
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- Qty in Cart
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- Price
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COMETIC Top End Gasket Kit - 82 mm - Suzuki C3409-EST
COMETIC
$69.95A top-end gasket failure can cost you a race and months of downtime. The COMETIC C3409-EST uses multi-layered steel construction with Viton rubber coating to handle the extreme pressures of modern 4-stroke engines, delivering reliable sealing on both...09347836- SKU:
- 09347836
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
$69.95 -
COMETIC Top End Gasket Kit - 84 mm - Suzuki C3410-EST
COMETIC
$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
$69.95 -
COMETIC Top End Gasket Kit - 97 mm - Yamaha C3540-EST
COMETIC
$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
$68.95 -
COMETIC Top End Gasket Kit - 88 mm - KTM C3605-EST
COMETIC
$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
$74.95 -
COMETIC Top End Gasket Kit - 96 mm - Honda C3621
COMETIC
$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
$85.95 -
COMETIC Top End Gasket Kit - 97 mm - Yamaha C3630
COMETIC
$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
$53.95 -
COMETIC Top End Gasket Kit - 82 mm - Honda C3735
COMETIC
$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
$67.95 -
COMETIC Top End Gasket Kit - KTM/Husqvarna C3808
COMETIC
$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
$92.95 -
COMETIC Top End Gasket Kit - 90 mm - KTM C3779-EST
COMETIC
$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
$74.95 -
COMETIC Top End Gasket Kit - KTM/Husqvarna/Gas Gas C3623
COMETIC
$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
$46.95 -
COMETIC Top End Gasket Kit - 90 mm - KTM/Husqvarna/Gas Gas C3790
COMETIC
$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
$97.95 -
COMETIC Top End Gasket Kit - 48 mm - Kawasaki/Suzuki C7737
COMETIC
$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
$28.95 -
COMETIC Top End Gasket Kit - 54.5 mm - Kawasaki C3543
COMETIC
$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
$31.95 -
COMETIC Top End Gasket Kit - 77 mm - Yamaha C3549-EST
COMETIC
$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
$74.95 -
COMETIC Top End Gasket Kit - 96 mm - Kawasaki C3696
COMETIC
$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
$85.95 -
COMETIC Top End Gasket Kit - 96 mm - Honda C3733
COMETIC
$85.95A failing top end gasket compromises combustion sealing and allows coolant or oil to escape—both catastrophic for engine reliability and performance. This COMETIC kit delivers OEM-correct fitment with multi-layer steel construction and Viton coating,...09347850- SKU:
- 09347850
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
$85.95 -
COMETIC Top End Gasket Kit - KTM/Husqvarna/Gas Gas C3636
COMETIC
$47.95A failed top-end gasket can cost you race time, engine damage, and thousands in repairs. The COMETIC C3636 kit delivers OEM-quality sealing with performance-grade materials engineered to handle the extreme pressures of modern 4-stroke engines. Whether...09347801- SKU:
- 09347801
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
$47.95 -
COMETIC Top End Gasket Kit - 80 mm - Yamaha C3766
COMETIC
$79.95A failing top-end gasket compromises combustion chamber sealing, killing power output and risking catastrophic engine damage. The COMETIC C3766 kit delivers the precision sealing your high-output engine demands, with multi-layered construction designed...09347852- SKU:
- 09347852
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
$79.95 -
COMETIC Top End Gasket Kit - 91 mm - KTM C3784-EST
COMETIC
$74.95A quality gasket kit is non-negotiable for any top-end rebuild—it's your seal against compression loss, coolant weeping, and catastrophic engine failure. The COMETIC C3784-EST delivers the sealing reliability you need with EST (Extreme Sealing...09347854- SKU:
- 09347854
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
$74.95 -
COMETIC Top End Gasket Kit - 97 mm - Yamaha C3786
COMETIC
$78.95A failing top end gasket will compromise combustion sealing and cost you power—or worse, create catastrophic engine damage. This Cometic kit delivers the complete solution with precision-engineered gaskets designed to handle high-horsepower 4-stroke...09347855- SKU:
- 09347855
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
$78.95
