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!
- Product
- Qty in Cart
- Quantity
- Price
- Subtotal
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COMETIC Top End Gasket Kit - Kawasaki C3803
COMETIC
$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
$84.95Qty in Cart: 0Quantity:Price:$84.95Subtotal: -
COMETIC Top End Gasket Kit - 96 mm - Kawasaki C3806
COMETIC
$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
$88.95 -
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 - 79 mm - Honda C3635
COMETIC
$67.95A quality top end gasket kit is critical for maintaining cylinder pressure and preventing catastrophic coolant or oil leaks—especially when running high-horsepower naturally aspirated or forced-induction builds. The COMETIC C3635 uses multi-layered steel...09347846- SKU:
- 09347846
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
$67.95Qty in Cart: 0Quantity:Price:$67.95Subtotal: -
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 - KTM/Husqvarna/Gas Gas C3811
COMETIC
$79.95A failed top end gasket can sideline your bike and compromise engine integrity—especially when you're pushing high horsepower through naturally aspirated or forced induction setups. This Cometic kit delivers the sealing reliability you need with MLS...09347803- SKU:
- 09347803
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
$79.95Qty in Cart: 0Quantity:Price:$79.95Subtotal: -
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 -
COMETIC Top End Gasket Kit - 79 mm - Kawasaki C3787
COMETIC
$84.95A failing head gasket will cost you power, reliability, and time on the track or in the shop. COMETIC's multi-layered steel design with Viton rubber coating distributes combustion pressure evenly across the sealing surface, reducing bore distortion and...09347856- SKU:
- 09347856
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
$84.95 -
COMETIC Top End Gasket Kit - 95 mm - KTM/Husqvarna/Gas Gas C3604-EST
COMETIC
$74.95A failing top end gasket compromises combustion sealing, kills power, and invites catastrophic engine damage. The COMETIC C3604-EST delivers OEM-spec sealing reliability with advanced multi-layer construction designed for high-output 4-stroke engines...09347807- SKU:
- 09347807
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
$74.95 -
COMETIC Top End Gasket Kit - 96 mm - Honda C3801
COMETIC
$85.95A failed head gasket means catastrophic engine damage and costly downtime. The COMETIC Top End Gasket Kit delivers the sealing integrity and thermal management your high-output engine demands, whether you're running naturally aspirated or forced...09347859- SKU:
- 09347859
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
$85.95 -
COMETIC Top End Gasket Kit - 88 mm - KTM/Husqvarna/Gas Gas C3810
COMETIC
$102.95A top end gasket kit failure can mean catastrophic engine damage and costly downtime. Cometic's multi-layered design with EST (Extreme Sealing Technology) delivers superior heat dissipation and bore consistency, eliminating hot spots that plague stock...09347862- SKU:
- 09347862
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
$102.95Qty in Cart: 0Quantity:Price:$102.95Subtotal: -
COMETIC Top End Gasket Kit - 97 mm - Yamaha C3813
COMETIC
$87.95A compromised top end gasket is one of the quickest ways to lose compression, power, and reliability. The COMETIC C3813 Top End Gasket Kit is engineered for high-output 4-stroke engines that demand precision sealing under extreme combustion pressures...09347863- SKU:
- 09347863
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
$87.95 -
COMETIC Top End Gasket Kit - KTM C3818
COMETIC
$47.95A quality top-end gasket kit is essential for maintaining cylinder pressure, preventing coolant leaks, and maximizing power output on high-performance 4-stroke engines. Cometic's EST (Extreme Sealing Technology) gaskets are engineered to handle the...09347864- SKU:
- 09347864
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
$47.95 -
COMETIC Top End Gasket Kit - 47 mm - Kawasaki/Suzuki C7682
COMETIC
$28.95A failing top-end gasket can compromise combustion chamber sealing, reduce ring seal efficiency, and lead to catastrophic engine failure. The COMETIC C7682 kit delivers OEM-spec sealing with multi-layer steel construction and Viton rubber coating,...09347866- SKU:
- 09347866
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
$28.95
