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
ATHENA Piston Kit S4C05000002A
ATHENA
MSRP: $100.95Now: $91.00Was: $100.95Includes rings, clips and pin, Easy-to-follow step-by-step installation instructions09101328- SKU:
- 09101328
- Availability:
- Ships Same Business Day
- Weight:
- 0.29 LBS
- PISTON DIAMETER METRIC:
- 49.95 MM
- PRODUCT NAME:
- PISTON
- COMPRESSION RATIO IMPERIAL:
- 15.0:1
- ENGINE TYPE:
- 2-STROKE
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- BIG BORE
- PISTON SIZE METRIC:
- STANDARD SIZE A
MSRP: $100.95Now: $91.00Was: $100.95 -
On Sale
ATHENA Piston Kit S4F08200005A
ATHENA
MSRP: $277.95Now: $250.00Was: $277.95Includes rings, clips and pin, Easy-to-follow step-by-step installation instructions09103414- SKU:
- 09103414
- Availability:
- Ships Same Business Day
- Weight:
- 0.74 LBS
- PISTON SIZE METRIC:
- STANDARD SIZE A
- ENGINE TYPE:
- 4-STROKE
- PISTON DIAMETER METRIC:
- 81.95 MM
- PRODUCT NAME:
- PISTON
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- COMPRESSION RATIO IMPERIAL:
- 16.0:1
- RIDING STYLE:
- STREET
- STYLE:
- BIG BORE
MSRP: $277.95Now: $250.00Was: $277.95Qty in Cart: 0Quantity:Price:MSRP: $277.95Now: $250.00Was: $277.95Subtotal: -
On Sale
ATHENA Piston Kit S4F05400017A
ATHENA
MSRP: $130.95Now: $118.00Was: $130.95Two-stroke pistons are made from 4032 silicium, Four-stroke pistons are made from 2618 silicium - the same material used to produce Formula 1 pistons, Both include 3% copper in materials for better heat resistance, All pistons are forged using a...09103891- SKU:
- 09103891
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- DISPLACEMENT:
- 124 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- A
- BORE SIZE METRIC:
- 53.95 MM
- PISTON HEAD SHAPE:
- FLAT TOP
- COMPRESSION RATIO IMPERIAL:
- STOCK
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
MSRP: $130.95Now: $118.00Was: $130.95Qty in Cart: 0Quantity:Price:MSRP: $130.95Now: $118.00Was: $130.95Subtotal: -
On Sale
ATHENA Complete Gasket Kit - Kawasaki P400250850030
ATHENA
MSRP: $70.95Now: $64.00Was: $70.95Superior-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...09341520- SKU:
- 09341520
- Availability:
- Ships Same Business Day
- Weight:
- 0.21 LBS
- PRODUCT NAME:
- GASKET KIT
- ENGINE TYPE:
- -
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
MSRP: $70.95Now: $64.00Was: $70.95 -
On Sale
ATHENA Gasket Kit - KX65 - 50 mm P400250160007
ATHENA
MSRP: $46.95Now: $42.00Was: $46.95Kits include aluminum cylinder with nickel-carbide coating designed with larger water jackets, Forged piston with molybdenum coating, Special gasket kit, Easy-to-follow step-by-step installation instructions, All are bolt-on; no machining required09341533- SKU:
- 09341533
- Availability:
- Ships Same Business Day
- Weight:
- 0.07 LBS
- BORE SIZE METRIC:
- 50.00 MM
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE:
- 50,00 MM
- PRODUCT NAME:
- GASKET KIT
- UNITS:
- KIT
- TYPE:
- TOP END
MSRP: $46.95Now: $42.00Was: $46.95 -
On Sale
ATHENA Gasket Kit - RMZ450 - 100 mm P400510160006
ATHENA
MSRP: $105.95Now: $95.00Was: $105.95Kits include aluminum cylinder with nickel-carbide coating designed with larger water jackets, Forged piston with molybdenum coating, Special gasket kit, Easy-to-follow step-by-step installation instructions, All are bolt-on; no machining required09341538- SKU:
- 09341538
- Availability:
- Ships Same Business Day
- Weight:
- 0.17 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 100.00 MM
- UNITS:
- KIT
- BORE SIZE:
- 100,00 MM
- TYPE:
- TOP END
MSRP: $105.95Now: $95.00Was: $105.95Qty in Cart: 0Quantity:Price:MSRP: $105.95Now: $95.00Was: $105.95Subtotal: -
On Sale
ATHENA Complete Gasket Kit - Kawasaki P400250850011
ATHENA
MSRP: $58.95Now: $53.00Was: $58.95Superior-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...09340204- SKU:
- 09340204
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
- ENGINE TYPE:
- -
- PRODUCT NAME:
- GASKET KIT
MSRP: $58.95Now: $53.00Was: $58.95 -
On Sale
ATHENA Top End Gasket Kit P400250600011
ATHENA
MSRP: $41.95Now: $38.00Was: $41.95Specifically 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...09340206- SKU:
- 09340206
- Availability:
- Ships Same Business Day
- Weight:
- 0.19 LBS
- TYPE:
- TOP END
- PRODUCT NAME:
- GASKET KIT
- UNITS:
- KIT
- MATERIAL:
- RUBBER
- RIDING STYLE:
- OFF-ROAD
MSRP: $41.95Now: $38.00Was: $41.95 -
On Sale
ATHENA Complete Gasket Kit - Suzuki P400510850034
ATHENA
MSRP: $42.95Now: $39.00Was: $42.95Superior-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...09340207- SKU:
- 09340207
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PRODUCT NAME:
- GASKET KIT
- ENGINE TYPE:
- -
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
MSRP: $42.95Now: $39.00Was: $42.95Qty in Cart: 0Quantity:Price:MSRP: $42.95Now: $39.00Was: $42.95Subtotal: -
On Sale
ATHENA Top End Gasket Kit P400510600034
ATHENA
MSRP: $21.95Now: $20.00Was: $21.95Specifically 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...09340210- SKU:
- 09340210
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- PRODUCT NAME:
- GASKET KIT
- ENGINE TYPE:
- 2-STROKE
- MATERIAL:
- RUBBER
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
MSRP: $21.95Now: $20.00Was: $21.95 -
On Sale
ATHENA Top End Gasket Kit P400510600035
ATHENA
MSRP: $42.95Now: $39.00Was: $42.95Specifically 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...09340211- SKU:
- 09340211
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- ENGINE TYPE:
- 2-STROKE
- MATERIAL:
- RUBBER
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- TOP END
MSRP: $42.95Now: $39.00Was: $42.95Qty in Cart: 0Quantity:Price:MSRP: $42.95Now: $39.00Was: $42.95Subtotal: -
On Sale
ATHENA Complete Gasket Kit - Yamaha P400485850053
ATHENA
MSRP: $163.95Now: $148.00Was: $163.95Superior-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...09340213- SKU:
- 09340213
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
MSRP: $163.95Now: $148.00Was: $163.95 -
On Sale
ATHENA Complete Gasket Kit - KTM P400270850003
ATHENA
MSRP: $28.95Now: $26.00Was: $28.95Superior-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...09340216- SKU:
- 09340216
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
- ENGINE TYPE:
- -
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
MSRP: $28.95Now: $26.00Was: $28.95 -
On Sale
ATHENA Cylinder Kit - CRF230F P400210100054
ATHENA
MSRP: $416.95Now: $375.00Was: $416.95Kits include aluminum cylinder with nickel-carbide coating designed with larger water jackets, Forged piston with molybdenum coating, Special gasket kit, Easy-to-follow step-by-step installation instructions, All are bolt-on; no machining required09310662- SKU:
- 09310662
- Availability:
- Ships Same Business Day
- Weight:
- 4.75 LBS
- STYLE:
- BIG BORE
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- ENGINE TYPE:
- 4-STROKE
- BORE SIZE METRIC:
- 67.00 MM
- MATERIAL:
- ALUMINUM
- DISPLACEMENT:
- 233 CC
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $416.95Now: $375.00Was: $416.95 -
On Sale
ATHENA Cylinder Kit - Suzuki RM-Z450 P400510100027
ATHENA
MSRP: $772.95Now: $696.00Was: $772.95Kits include aluminum cylinder with nickel-carbide coating designed with larger water jackets, Forged piston with molybdenum coating, Special gasket kit, Easy-to-follow step-by-step installation instructions, All are bolt-on; no machining required09310678- SKU:
- 09310678
- Availability:
- Ships Same Business Day
- Weight:
- 4.05 LBS
- DISPLACEMENT:
- 450 CC
- MATERIAL:
- ALUMINUM
- STYLE:
- STOCK BORE
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- ENGINE TYPE:
- 4-STROKE
- BORE SIZE METRIC:
- 96.00 MM
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
MSRP: $772.95Now: $696.00Was: $772.95 -
On Sale
ATHENA Cylinder Kit - Suzuki RM-Z450 P400510100028
ATHENA
MSRP: $1,151.95Now: $1,037.00Was: $1,151.95Kits include aluminum cylinder with nickel-carbide coating designed with larger water jackets, Forged piston with molybdenum coating, Special gasket kit, Easy-to-follow step-by-step installation instructions, All are bolt-on; no machining required09310679- SKU:
- 09310679
- Availability:
- Ships Same Business Day
- Weight:
- 3.80 LBS
- DISPLACEMENT:
- 490 CC
- MATERIAL:
- ALUMINUM
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- ENGINE TYPE:
- 4-STROKE
- BORE SIZE METRIC:
- 100.00 MM
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- BIG BORE
- UNITS:
- KIT
MSRP: $1,151.95Now: $1,037.00Was: $1,151.95Qty in Cart: 0Quantity:Price:MSRP: $1,151.95Now: $1,037.00Was: $1,151.95Subtotal: -
On Sale
ATHENA Cylinder Kit - Honda - Stock P400210100066
ATHENA
MSRP: $819.33Now: $696.00Was: $819.33Kits include aluminum cylinder with nickel-carbide coating designed with larger water jackets, Forged piston with molybdenum coating, Special gasket kit, Easy-to-follow step-by-step installation instructions, All are bolt-on; no machining required09310955- SKU:
- 09310955
- Availability:
- Ships Same Business Day
- Weight:
- 3.36 LBS
- DISPLACEMENT:
- 250 CC
- MATERIAL:
- ALUMINUM
- STYLE:
- STOCK BORE
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- ENGINE TYPE:
- 4-STROKE
- BORE SIZE METRIC:
- 79.00 MM
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $819.33Now: $696.00Was: $819.33Qty in Cart: 0Quantity:Price:MSRP: $819.33Now: $696.00Was: $819.33Subtotal: -
On Sale
ATHENA Cylinder Kit - Honda - Big Bore P400210100067
ATHENA
MSRP: $1,166.95Now: $1,050.00Was: $1,166.95Kits include aluminum cylinder with nickel-carbide coating designed with larger water jackets, Forged piston with molybdenum coating, Special gasket kit, Easy-to-follow step-by-step installation instructions, All are bolt-on; no machining required09310956- SKU:
- 09310956
- Availability:
- Ships Same Business Day
- Weight:
- 3.71 LBS
- DISPLACEMENT:
- 289 CC
- MATERIAL:
- ALUMINUM
- BORE SIZE METRIC:
- 82.00 MM
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- BIG BORE
- UNITS:
- KIT
- ENGINE TYPE:
- 4-STROKE
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
MSRP: $1,166.95Now: $1,050.00Was: $1,166.95 -
On Sale
ATHENA Cylinder Kit - Honda - Stock P400210100059
ATHENA
MSRP: $772.95Now: $696.00Was: $772.95Kits include aluminum cylinder with nickel-carbide coating designed with larger water jackets, Forged piston with molybdenum coating, Special gasket kit, Easy-to-follow step-by-step installation instructions, All are bolt-on; no machining required09310957- SKU:
- 09310957
- Availability:
- Ships Same Business Day
- Weight:
- 4.06 LBS
- PRODUCT NAME:
- CYLINDER KIT
- DISPLACEMENT:
- 450 CC
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- STOCK BORE
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- UNITS:
- KIT
- BORE SIZE METRIC:
- 96.00 MM
- ENGINE TYPE:
- 4-STROKE
- MATERIAL:
- ALUMINUM
MSRP: $772.95Now: $696.00Was: $772.95 -
On Sale
ATHENA Cylinder Kit - Kawasaki - Stock P400250100022
ATHENA
MSRP: $772.95Now: $696.00Was: $772.95Kits include aluminum cylinder with nickel-carbide coating designed with larger water jackets, Forged piston with molybdenum coating, Special gasket kit, Easy-to-follow step-by-step installation instructions, All are bolt-on; no machining required09310961- SKU:
- 09310961
- Availability:
- Ships Same Business Day
- Weight:
- 4.41 LBS
- ENGINE TYPE:
- 4-STROKE
- CYLINDER BORE COATING:
- NICKEL-CARBIDE
- BORE SIZE METRIC:
- 96.00 MM
- DISPLACEMENT:
- 450 CC
- MATERIAL:
- ALUMINUM
- STYLE:
- STOCK BORE
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $772.95Now: $696.00Was: $772.95Qty in Cart: 0Quantity:Price:MSRP: $772.95Now: $696.00Was: $772.95Subtotal:
