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!
- Product
- Qty in Cart
- Quantity
- Price
- Subtotal
-
On Sale
ATHENA Top End Gasket Kit - Yamaha P400485600053
ATHENA
MSRP: $96.95Now: $87.00Was: $96.95Engine performance hinges on precision gasket sealing, and the ATHENA Top End Gasket Kit delivers the reliability competitive riders demand when refreshing their powerplant before race season or mid-event maintenance. This kit eliminates guesswork by...09342580- SKU:
- 09342580
- Availability:
- Ships Same Business Day
- Weight:
- 0.22 LBS
- UNITS:
- KIT
- TYPE:
- TOP END
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- ATV
MSRP: $96.95Now: $87.00Was: $96.95Qty in Cart: 0Quantity:Price:MSRP: $96.95Now: $87.00Was: $96.95Subtotal: -
On Sale
ATHENA Top End Gasket Kit - Kawasaki P400250600047
ATHENA
MSRP: $86.95Now: $78.00Was: $86.95Engine freshening before a race requires precision components that won't compromise reliability when it matters most. The ATHENA Top End Gasket Kit delivers OEM-quality sealing for pro, semi-pro, and amateur applications—giving you the flexibility to run...09342577- SKU:
- 09342577
- Availability:
- Ships Same Business Day
- Weight:
- 0.19 LBS
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- TOP END
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $86.95Now: $78.00Was: $86.95 -
On Sale
ATHENA Top End Gasket Kit - Honda P400210600064
ATHENA
MSRP: $86.95Now: $78.00Was: $86.95Whether you're prepping for race day or executing a midseason engine refresh, the ATHENA Top End Gasket Kit delivers the precision sealing your engine demands. This kit gives you flexibility—run stock compression with pump gas for reliability, or step up...09342574- SKU:
- 09342574
- Availability:
- Ships Same Business Day
- Weight:
- 0.24 LBS
- TYPE:
- TOP END
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
MSRP: $86.95Now: $78.00Was: $86.95Qty in Cart: 0Quantity:Price:MSRP: $86.95Now: $78.00Was: $86.95Subtotal: -
On Sale
ATHENA Top End Gasket Kit - Honda P400210600239
ATHENA
MSRP: $102.95Now: $93.00Was: $102.95Whether you're prepping for race day or executing a midseason engine refresh, the ATHENA Top End Gasket Kit ensures a proper seal on your Honda's critical combustion chamber surfaces. This kit gives you the flexibility to run standard fuel with stock...09342573- SKU:
- 09342573
- Availability:
- Ships Same Business Day
- Weight:
- 0.23 LBS
- TYPE:
- TOP END
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
MSRP: $102.95Now: $93.00Was: $102.95 -
On Sale
ATHENA Gasket Kit - YZ450F P400485160025
ATHENA
MSRP: $98.95Now: $89.00Was: $98.95The ATHENA Gasket Kit delivers the reliability and thermal management your YZ450F demands when you're pushing peak performance. Built with precision-engineered components and premium coatings, this kit ensures proper cylinder sealing and heat dissipation...09342555- SKU:
- 09342555
- Availability:
- Ships Same Business Day
- Weight:
- 0.22 LBS
- TYPE:
- TOP END
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE SIZE:
- 102,00 MM
- BORE SIZE METRIC:
- 102.00 MM
MSRP: $98.95Now: $89.00Was: $98.95Qty in Cart: 0Quantity:Price:MSRP: $98.95Now: $89.00Was: $98.95Subtotal: -
On Sale
ATHENA Complete Gasket Kit - Honda P400210850187
ATHENA
MSRP: $98.95Now: $89.00Was: $98.95A complete top-end rebuild demands gaskets that can handle extreme temperatures and maintain compression cycle after cycle. The ATHENA Complete Gasket Kit delivers the reliability you need with factory-quality construction across every critical seal...09342542- SKU:
- 09342542
- Availability:
- Ships Same Business Day
- Weight:
- 0.36 LBS
- ENGINE TYPE:
- -
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
MSRP: $98.95Now: $89.00Was: $98.95 -
On Sale
ATHENA Top End Gasket Kit - Honda P400210600245
ATHENA
MSRP: $69.95Now: $63.00Was: $69.95Engine gasket integrity is critical to maintaining peak compression and preventing mid-race failures. The ATHENA Top End Gasket Kit gives you the flexibility to optimize your fuel strategy—run pump gas with stock compression or unleash higher compression...09342537- SKU:
- 09342537
- Availability:
- Ships Same Business Day
- Weight:
- 0.24 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- TOP END
MSRP: $69.95Now: $63.00Was: $69.95Qty in Cart: 0Quantity:Price:MSRP: $69.95Now: $63.00Was: $69.95Subtotal: -
On Sale
ATHENA Top End Gasket Kit - Suzuki P400510600098
ATHENA
MSRP: $73.95Now: $67.00Was: $73.95Engine freshening before race season requires precision-engineered gaskets that can handle varying fuel grades and compression ratios without compromise. The ATHENA Top End Gasket Kit gives you the flexibility to run either pump gas with stock...09342536- SKU:
- 09342536
- Availability:
- Ships Same Business Day
- Weight:
- 0.28 LBS
- MATERIAL:
- RUBBER
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
MSRP: $73.95Now: $67.00Was: $73.95 -
On Sale
ATHENA Top End Gasket Kit - Yamaha P400485600039
ATHENA
MSRP: $79.95Now: $72.00Was: $79.95When you're preparing for race day, a fresh top end is non-negotiable. The ATHENA Top End Gasket Kit gives you the flexibility to optimize your engine for either pump gas with stock compression or unleash higher compression with race fuel—letting you...09342534- SKU:
- 09342534
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- TOP END
MSRP: $79.95Now: $72.00Was: $79.95Qty in Cart: 0Quantity:Price:MSRP: $79.95Now: $72.00Was: $79.95Subtotal: -
On Sale
ATHENA Top End Gasket Kit - Kawasaki P400250600024
ATHENA
MSRP: $86.95Now: $78.00Was: $86.95A top-end gasket kit is essential maintenance for any engine rebuild or mid-season refresh, especially when you're preparing for race day. The ATHENA P400250600024 gives you the flexibility to run either standard fuel with stock compression or premium...09342533- SKU:
- 09342533
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- TYPE:
- TOP END
- MATERIAL:
- RUBBER
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
MSRP: $86.95Now: $78.00Was: $86.95 -
K&S TECHNOLOGIES Water Pump Repair Kit 75-6001
K&S TECHNOLOGIES
$20.95A failing water pump can quickly turn a race day into a costly disaster. This K&S Technologies repair kit gives you everything needed to restore your pump to factory specifications without replacing the entire assembly, saving time and money while...09342527- SKU:
- 09342527
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- TYPE:
- WATER PUMP REPAIR
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- GASKET KIT
$20.95Qty in Cart: 0Quantity:Price:$20.95Subtotal: -
COMETIC Top End Gasket Set C3174-EST
COMETIC
$91.95A failing head gasket will leave you stranded, and factory gaskets simply can't handle the pressures of high-output 4-stroke engines. The COMETIC C3174-EST Top End Gasket Set uses multi-layered steel construction with proprietary Viton rubber coating to...09342432- SKU:
- 09342432
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- TYPE:
- TOP END
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 77.00 MM
- PRODUCT NAME:
- GASKET KIT
$91.95Qty in Cart: 0Quantity:Price:$91.95Subtotal: -
COMETIC Top End Gasket Set C3268-EST
COMETIC
$84.95A failing head gasket can cost you an entire season. The COMETIC C3268-EST Top End Gasket Set uses multi-layered steel construction with Viton rubber coating to handle extreme cylinder pressures—whether you're running naturally aspirated or boosted power...09342420- SKU:
- 09342420
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- GASKET KIT
- BORE SIZE METRIC:
- 96.00 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- TOP END
$84.95Qty in Cart: 0Quantity:Price:$84.95Subtotal: -
COMETIC Top End Gasket Set C3267-EST
COMETIC
$91.95High-output 4-stroke engines demand gasket technology that can withstand extreme combustion pressures and heat cycles without compromising the seal. COMETIC's EST gasket set uses multi-layered steel construction with proprietary Viton rubber coating to...09342414- SKU:
- 09342414
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
- BORE SIZE METRIC:
- 78.00 MM
- TYPE:
- TOP END
$91.95Qty in Cart: 0Quantity:Price:$91.95Subtotal: -
COMETIC Top End Gasket Set C7924-EST
COMETIC
$98.95If you're running a high-output 4-stroke engine—whether naturally aspirated or boosted—a quality gasket set is non-negotiable for reliability and performance. The COMETIC C7924-EST combines multi-layered steel construction with EST (Extreme Sealing...09342410- SKU:
- 09342410
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- BORE SIZE METRIC:
- 87.00 MM
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- ATV
- TYPE:
- TOP END
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$98.95Qty in Cart: 0Quantity:Price:$98.95Subtotal: -
COMETIC Top End Gasket Set C3187-EST
COMETIC
$64.95A quality top-end gasket set is non-negotiable for any engine rebuild or refresh—poor sealing leads to compression loss, oil weeping, and catastrophic failure under boost or high RPM. The COMETIC C3187-EST uses multi-layered steel construction with Viton...09342405- SKU:
- 09342405
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- BORE SIZE METRIC:
- 66.00 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- TOP END
$64.95Qty in Cart: 0Quantity:Price:$64.95Subtotal: -
COMETIC Top End Gasket Set C3416
COMETIC
$44.95A failed head gasket can sideline your engine and drain your wallet fast. The COMETIC C3416 Top End Gasket Set uses multi-layered steel construction with Viton rubber coating to handle the extreme pressures of today's high-output 4-stroke engines—whether...09342395- SKU:
- 09342395
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- BORE SIZE METRIC:
- 45.00 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- TOP END
- PRODUCT NAME:
- GASKET KIT
$44.95 -
Cylinder Works Big Bore Gasket Kit Yamaha YFZ450 2004-2009 2012-2013 23001-G01
CYLINDER WORKS
$112.95When you're pushing your YFZ450 to its limits, stock cylinder components become your bottleneck. The Cylinder Works Big Bore Gasket Kit delivers measurable gains in displacement and power without requiring extensive machine work or re-plating—just bolt...09342387- SKU:
- 09342387
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- RIDING STYLE:
- UTV
- TYPE:
- TOP END
- PRODUCT NAME:
- GASKET KIT
- STYLE:
- BIG BORE
- UNITS:
- KIT
$112.95Qty in Cart: 0Quantity:Price:$112.95Subtotal: -
Cylinder Works Big Bore Gasket Kit 79mm Bore 2005-2012 KTM 250 SX-F 51002-G01
CYLINDER WORKS
$143.95If you're running a 2005-2012 KTM 250 SX-F and want measurable gains in displacement, durability, and reliability without extensive machine work, a big bore kit is the most direct path forward. This Cylinder Works system delivers a complete 79mm bore...09342370- SKU:
- 09342370
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- MATERIAL:
- NICKEL SILICON CARBIDE
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- BIG BORE
- UNITS:
- KIT
- TYPE:
- TOP END
$143.95 -
Cylinder Works Big Bore Gasket Kit KTM 350 SX-F 2011-2012 51001-G01
CYLINDER WORKS
$149.95If you're running a KTM 350 SX-F and looking to extract real performance gains, a big bore kit is one of the most effective bolt-on upgrades available. This Cylinder Works system delivers increased displacement and compression without requiring machine...09342369- SKU:
- 09342369
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MATERIAL:
- NICKEL SILICON CARBIDE
- STYLE:
- BIG BORE
- TYPE:
- TOP END
- PRODUCT NAME:
- GASKET KIT
$149.95
