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
-
On Sale
HOT RODS Seal Output Shaft OSK0016
HOT RODS
MSRP: $35.95Now: $32.36Was: $35.95A quick solution to repairing a leaking countershaft seal in one complete kit, Includes Hot Rods countershaft seal, countershaft bushing, O-rings, and sprocket nut washer (where applicable), Kits do not include water pump bearing or transmission bearings.09350581- SKU:
- 09350581
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- SEAL
- APPLICATION:
- COUNTERSHAFT
- APPLICATION:
- TRANSMISSION
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $35.95Now: $32.36Was: $35.95 -
On Sale
ATHENA Water Pump Gasket Kit - KTM P400270475001
ATHENA
MSRP: $37.95Now: $34.00Was: $37.95Include water pump gasket, clutch cover gasket, water pump shaft oil seals and washers, Kit contents will vary slightly based on application, Kits do not contain replacement bearings09346063- SKU:
- 09346063
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- WATER PUMP
MSRP: $37.95Now: $34.00Was: $37.95 -
On Sale
ATHENA Water Pump Gasket Kit - Kawasaki P400250475012
ATHENA
MSRP: $68.95Now: $62.00Was: $68.95Include water pump gasket, clutch cover gasket, water pump shaft oil seals and washers, Kit contents will vary slightly based on application, Kits do not contain replacement bearings09346060- SKU:
- 09346060
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- WATER PUMP
MSRP: $68.95Now: $62.00Was: $68.95Qty in Cart: 0Quantity:Price:MSRP: $68.95Now: $62.00Was: $68.95Subtotal: -
On Sale
ATHENA Water Pump Gasket Kit - Kawasaki P400250475009
ATHENA
MSRP: $50.95Now: $46.00Was: $50.95Include water pump gasket, clutch cover gasket, water pump shaft oil seals and washers, Kit contents will vary slightly based on application, Kits do not contain replacement bearings09346057- SKU:
- 09346057
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- WATER PUMP
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
MSRP: $50.95Now: $46.00Was: $50.95Qty in Cart: 0Quantity:Price:MSRP: $50.95Now: $46.00Was: $50.95Subtotal: -
On Sale
ATHENA Water Pump Gasket Kit - Honda P400210475012
ATHENA
MSRP: $33.95Now: $31.00Was: $33.95Include water pump gasket, clutch cover gasket, water pump shaft oil seals and washers, Kit contents will vary slightly based on application, Kits do not contain replacement bearings09346048- SKU:
- 09346048
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- WATER PUMP
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
MSRP: $33.95Now: $31.00Was: $33.95 -
On Sale
Cylinder Works Big Bore Gasket Kit for Yamaha YZ250 1999-2020 21009-G01
CYLINDER WORKS
MSRP: $113.95Now: $102.56Was: $113.95Elevate your engine's performance with the CYLINDER WORKS Big Bore Gasket Kit 21009-G01. Designed for a seamless installation, this kit offers a high-quality upgrade that enhances longevity and reduces engine noise, all while maintaining a look that...09344757- SKU:
- 09344757
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
- STYLE:
- BIG BORE
- PRODUCT NAME:
- GASKET KIT
MSRP: $113.95Now: $102.56Was: $113.95Qty in Cart: 0Quantity:Price:MSRP: $113.95Now: $102.56Was: $113.95Subtotal: -
On Sale
COMETIC Bottom End Gasket Set - Yamaha C7507BE
COMETIC
MSRP: $90.95Now: $85.00Was: $90.95Bottom end gasket kits include correct oil seals, O-rings, drain plug washers and water pump cover gaskets as needed, Materials will vary depending on what is correct and engineered for specified application, Purchase a top and a bottom end gasket kit...09344304- SKU:
- 09344304
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- BOTTOM END
- MODEL:
- HI-PERFORMANCE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $90.95Now: $85.00Was: $90.95Qty in Cart: 0Quantity:Price:MSRP: $90.95Now: $85.00Was: $90.95Subtotal: -
On Sale
COMETIC Top End Gasket Set - Honda C7278
COMETIC
MSRP: $42.95Now: $40.00Was: $42.95Top end gasket kits include correct base, head gasket and cylinder O-rings as well as other top end specific O-rings or seals needed for R&R of top end, MLS head gaskets promote an even torque load across the gasket sealing surface, providing less bore...09344269- SKU:
- 09344269
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- BORE SIZE METRIC:
- 71.00 MM
- THICKNESS IMPERIAL:
- 0,012'
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- TOP END
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- THICKNESS METRIC:
- 0.31 MM
MSRP: $42.95Now: $40.00Was: $42.95Qty in Cart: 0Quantity:Price:MSRP: $42.95Now: $40.00Was: $42.95Subtotal: -
On Sale
HOT RODS Water Pump Repair Kit - Honda WPK0003
HOT RODS
MSRP: $63.95Now: $57.56Was: $63.95Kits include water pump cover gasket, water pump shaft bearing(s) and seal(s) to repair a leaking pump or failed bearing, Precision micro bearings provide OEM quality and durability, High-pressure/temperature mechanical and rubber seals, Does not include...09342915- SKU:
- 09342915
- Availability:
- Ships Same Business Day
- Weight:
- 0.12 LBS
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- WATER PUMP REPAIR
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
MSRP: $63.95Now: $57.56Was: $63.95 -
On Sale
ATHENA Top End Gasket Kit - Yamaha P400485600069
ATHENA
MSRP: $96.95Now: $87.00Was: $96.95Specifically designed for the pro, semi-pro and amateur rider who freshens up their engine prior to a race or during midseason. Gives the rider a choice of using standard gas with stock compression, or race gas with a higher compression. Kits do not...09342581- SKU:
- 09342581
- Availability:
- Ships Same Business Day
- Weight:
- 0.21 LBS
- TYPE:
- TOP END
- UNITS:
- KIT
- 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 Complete Gasket Kit - Honda P400210850202
ATHENA
MSRP: $164.95Now: $148.00Was: $164.95Superior-quality gasket sets from Athena, Head gaskets feature rubber-coated spring steel construction, Soft steel base gaskets are rubber coated, Steel core materials feature high springback and superior tensile strength, Revolutionary transparent...09342541- SKU:
- 09342541
- Availability:
- Ships Same Business Day
- Weight:
- 0.28 LBS
- PRODUCT NAME:
- GASKET KIT
- ENGINE TYPE:
- -
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
MSRP: $164.95Now: $148.00Was: $164.95Qty in Cart: 0Quantity:Price:MSRP: $164.95Now: $148.00Was: $164.95Subtotal: -
On Sale
ATHENA Top End Gasket Kit - Honda P400210600187
ATHENA
MSRP: $84.95Now: $76.00Was: $84.95Specifically designed for the pro, semi-pro and amateur rider who freshens up their engine prior to a race or during midseason. Gives the rider a choice of using standard gas with stock compression, or race gas with a higher compression. Kits do not...09342540- SKU:
- 09342540
- Availability:
- Ships Same Business Day
- Weight:
- 0.19 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- TOP END
MSRP: $84.95Now: $76.00Was: $84.95Qty in Cart: 0Quantity:Price:MSRP: $84.95Now: $76.00Was: $84.95Subtotal: -
On Sale
ATHENA Top End Gasket Kit - KTM P400270600056
ATHENA
MSRP: $96.95Now: $87.00Was: $96.95Specifically designed for the pro, semi-pro and amateur rider who freshens up their engine prior to a race or during midseason. Gives the rider a choice of using standard gas with stock compression, or race gas with a higher compression. Kits do not...09342539- SKU:
- 09342539
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
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 - Honda P400210600202
ATHENA
MSRP: $58.95Now: $53.00Was: $58.95Specifically designed for the pro, semi-pro and amateur rider who freshens up their engine prior to a race or during midseason. Gives the rider a choice of using standard gas with stock compression, or race gas with a higher compression. Kits do not...09342538- SKU:
- 09342538
- Availability:
- Ships Same Business Day
- Weight:
- 0.19 LBS
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- TOP END
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $58.95Now: $53.00Was: $58.95Qty in Cart: 0Quantity:Price:MSRP: $58.95Now: $53.00Was: $58.95Subtotal: -
On Sale
COMETIC Bottom End Gasket Set C3299
COMETIC
MSRP: $15.95Now: $15.00Was: $15.95Bottom end gasket kits include correct oil seals, O-rings, drain plug washers and water pump cover gaskets as needed, Materials will vary depending on what is correct and engineered for specified application, Purchase a top and a bottom end gasket kit...09342514- SKU:
- 09342514
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- GASKET KIT
- MODEL:
- HI-PERFORMANCE
- TYPE:
- BOTTOM END
- BORE SIZE METRIC:
- 55.00 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $15.95Now: $15.00Was: $15.95 -
On Sale
COMETIC Top End Gasket Set C3395-EST
COMETIC
MSRP: $68.95Now: $65.00Was: $68.95Top end gasket kits include correct base, head gasket and cylinder O-rings as well as other top end specific O-rings or seals needed for R&R of top end, MLS head gaskets promote an even torque load across the gasket sealing surface, providing less bore...09342451- SKU:
- 09342451
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- PRODUCT NAME:
- GASKET KIT
- BORE SIZE IMPERIAL:
- 3.819'
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- TOP END
MSRP: $68.95Now: $65.00Was: $68.95Qty in Cart: 0Quantity:Price:MSRP: $68.95Now: $65.00Was: $68.95Subtotal: -
On Sale
COMETIC Top End Gasket Set C7944-EST
COMETIC
MSRP: $84.95Now: $80.00Was: $84.95Top end gasket kits include correct base, head gasket and cylinder O-rings as well as other top end specific O-rings or seals needed for R&R of top end, MLS head gaskets promote an even torque load across the gasket sealing surface, providing less bore...09342426- SKU:
- 09342426
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- TOP END
- BORE SIZE METRIC:
- 95.00 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
MSRP: $84.95Now: $80.00Was: $84.95 -
On Sale
Cylinder Works Big Bore Gasket Kit for 2010-2017 Honda CRF250R 11007-G01
CYLINDER WORKS
MSRP: $75.95Now: $68.36Was: $75.95Elevate your engine's performance with the CYLINDER WORKS Big Bore Gasket Kit 11007-G01. Designed for seamless installation, this kit offers a perfect fit without the need for re-plating, ensuring your ride maintains its OEM appearance while enhancing...09342383- SKU:
- 09342383
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MATERIAL:
- NICKEL SILICON CARBIDE
- BORE SIZE METRIC:
- OVERSIZED (+3.00 MM)
- TYPE:
- TOP END
- PRODUCT NAME:
- GASKET KIT
- STYLE:
- BIG BORE
MSRP: $75.95Now: $68.36Was: $75.95Qty in Cart: 0Quantity:Price:MSRP: $75.95Now: $68.36Was: $75.95Subtotal: -
On Sale
Cylinder Works Big Bore Gasket Kit for 2009-2016 Kawasaki KX250F 31004-G01
CYLINDER WORKS
MSRP: $92.95Now: $83.66Was: $92.95Enhance your engine's performance with the CYLINDER WORKS Big Bore Gasket Kit 31004-G01. This comprehensive kit offers a direct bolt-on solution, providing a seamless upgrade without the need for re-plating. Crafted with precision, it includes...09341929- SKU:
- 09341929
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- BORE SIZE METRIC:
- OVERSIZED (+3.00 MM)
- MATERIAL:
- NICKEL SILICON CARBIDE
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- BIG BORE
- UNITS:
- KIT
- TYPE:
- TOP END
MSRP: $92.95Now: $83.66Was: $92.95Qty in Cart: 0Quantity:Price:MSRP: $92.95Now: $83.66Was: $92.95Subtotal: -
On Sale
ATHENA Complete Gasket Kit - KTM P400270850019
ATHENA
MSRP: $142.95Now: $129.00Was: $142.95Superior-quality gasket sets from Athena, Head gaskets feature rubber-coated spring steel construction, Soft steel base gaskets are rubber coated, Steel core materials feature high springback and superior tensile strength, Revolutionary transparent...09341819- SKU:
- 09341819
- Availability:
- Ships Same Business Day
- Weight:
- 0.49 LBS
- RIDING STYLE:
- STREET
- TYPE:
- COMPLETE
- UNITS:
- KIT
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- GASKET KIT
MSRP: $142.95Now: $129.00Was: $142.95Qty in Cart: 0Quantity:Price:MSRP: $142.95Now: $129.00Was: $142.95Subtotal:
