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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ATHENA Piston Kit S4F05400017C
ATHENA
$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...09103893- SKU:
- 09103893
- Availability:
- Ships Same Business Day
- Weight:
- 0.60 LBS
- BORE SIZE METRIC:
- 53.97 MM
- DISPLACEMENT:
- 124 CC
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- C
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- PISTON KIT
- COMPRESSION RATIO IMPERIAL:
- STOCK
- PISTON HEAD SHAPE:
- FLAT TOP
- UNITS:
- KIT
$130.95Qty in Cart: 0Quantity:Price:$130.95Subtotal: -
ATHENA Piston Kit S4F06640018C
ATHENA
$187.95Two-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...09103894- SKU:
- 09103894
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- DISPLACEMENT:
- 249 CC
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- BORE SIZE METRIC:
- 66.36 MM
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- PISTON HEAD SHAPE:
- DOMED
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- C
- COMPRESSION RATIO IMPERIAL:
- STOCK
- UNITS:
- KIT
$187.95Qty in Cart: 0Quantity:Price:$187.95Subtotal: -
ATHENA Piston Kit S4C04850003B
ATHENA
$119.95Two-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...09104655- SKU:
- 09104655
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 48.45 MM
- COMPRESSION RATIO IMPERIAL:
- STOCK
- PISTON HEAD SHAPE:
- DOMED
- UNITS:
- KIT
- DISPLACEMENT:
- 85 CC
- TYPE:
- B
- PRODUCT NAME:
- PISTON KIT
$119.95Qty in Cart: 0Quantity:Price:$119.95Subtotal: -
ATHENA Top End Gasket Kit P400250600015
ATHENA
$34.95Specifically 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...09340205- SKU:
- 09340205
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- MATERIAL:
- RUBBER
- UNITS:
- KIT
- TYPE:
- TOP END
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
$34.95 -
ATHENA Complete Gasket Kit - Suzuki P400510850035
ATHENA
$78.95Superior-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...09340208- SKU:
- 09340208
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
- ENGINE TYPE:
- 2-STROKE
$78.95Qty in Cart: 0Quantity:Price:$78.95Subtotal: -
ATHENA Gasket Kit - WR250R/X - 83 mm P400485160017
ATHENA
$99.95Kits 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 required09341846- SKU:
- 09341846
- Availability:
- Ships Same Business Day
- Weight:
- 0.22 LBS
- BORE SIZE METRIC:
- 83.00 MM
- DISPLACEMENT:
- 290 CC
- TYPE:
- TOP END
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- BORE SIZE:
- 83,00 MM
$99.95Qty in Cart: 0Quantity:Price:$99.95Subtotal: -
ATHENA Complete Gasket Kit - Husqvarna P400220850261
ATHENA
$256.95Superior-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...09342788- SKU:
- 09342788
- Availability:
- Ships Same Business Day
- Weight:
- 0.51 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
- ENGINE TYPE:
- -
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- GASKET KIT
$256.95Qty in Cart: 0Quantity:Price:$256.95Subtotal: -
ATHENA Complete Gasket Kit - KX250 P400250850021
ATHENA
$105.95Head gaskets feature rubber-coated spring steel construction, Soft steel base gaskets are rubber coated, Steel core materials feature high spring-back and superior tensile strength, Revolutionary transparent coating guarantees a perfect seal even at...09342790- SKU:
- 09342790
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
$105.95Qty in Cart: 0Quantity:Price:$105.95Subtotal: -
ATHENA Complete Gasket Kit - KTM P400270850049
ATHENA
$103.95Superior-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...09342791- SKU:
- 09342791
- Availability:
- Ships Same Business Day
- Weight:
- 0.17 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
- ENGINE TYPE:
- -
- PRODUCT NAME:
- GASKET KIT
$103.95 -
ATHENA Complete Gasket Kit - KTM P400270850028
ATHENA
$129.95Superior-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...09342792- SKU:
- 09342792
- Availability:
- Ships Same Business Day
- Weight:
- 0.37 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- RIDING STYLE:
- STREET
- ENGINE TYPE:
- -
- PRODUCT NAME:
- GASKET KIT
- UNITS:
- KIT
$129.95Qty in Cart: 0Quantity:Price:$129.95Subtotal: -
ATHENA Race Gasket Kit - CRF250R R2106-245
ATHENA
$55.95Specifically designed for the pro, semi-pro and amateur rider who freshens up their engine prior to a race or during mid-season, Kits include a top-of-the line MLSS head gasket and two or more premium-quality base gaskets of different thicknesses to...09342807- SKU:
- 09342807
- Availability:
- Ships Same Business Day
- Weight:
- 0.23 LBS
- MATERIAL:
- RUBBER
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MATERIAL:
- STEEL
- TYPE:
- TOP END
- PRODUCT NAME:
- GASKET KIT
- STYLE:
- RACE
$55.95Qty in Cart: 0Quantity:Price:$55.95Subtotal: -
ATHENA Complete Gasket Kit - KTM P400270900061
ATHENA
$176.95Superior-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...09343011- SKU:
- 09343011
- Availability:
- Ships Same Business Day
- Weight:
- 0.65 LBS
- UNITS:
- KIT
- ENGINE TYPE:
- -
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- STREET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
$176.95 -
ATHENA Top End Gasket Kit - Honda P400210600172
ATHENA
$113.95Specifically 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...09343023- SKU:
- 09343023
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- ATV
- TYPE:
- TOP END
- UNITS:
- KIT
$113.95Qty in Cart: 0Quantity:Price:$113.95Subtotal: -
ATHENA Top End Gasket Kit - Honda P400210600198
ATHENA
$78.95Specifically 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...09343024- SKU:
- 09343024
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- ATV
- TYPE:
- TOP END
$78.95Qty in Cart: 0Quantity:Price:$78.95Subtotal: -
ATHENA Top End Gasket Kit - Kawasaki P400250600029
ATHENA
$119.95Specifically 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...09343028- SKU:
- 09343028
- Availability:
- Ships Same Business Day
- Weight:
- 0.21 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- ATV
- TYPE:
- TOP END
- MATERIAL:
- SILICONE
- UNITS:
- KIT
$119.95Qty in Cart: 0Quantity:Price:$119.95Subtotal: -
ATHENA Top End Gasket Kit - Yamaha P400485600156
ATHENA
$131.95Specifically 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...09343034- SKU:
- 09343034
- Availability:
- Ships Same Business Day
- Weight:
- 0.24 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- ATV
- TYPE:
- TOP END
- UNITS:
- KIT
$131.95Qty in Cart: 0Quantity:Price:$131.95Subtotal: -
ATHENA Complete Gasket Kit - Yamaha P400485850078
ATHENA
$156.95Superior-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...09343045- SKU:
- 09343045
- Availability:
- Ships Same Business Day
- Weight:
- 0.49 LBS
- RIDING STYLE:
- ATV
- TYPE:
- COMPLETE
- ENGINE TYPE:
- -
- PRODUCT NAME:
- GASKET KIT
- UNITS:
- KIT
$156.95Qty in Cart: 0Quantity:Price:$156.95Subtotal: -
ATHENA Complete Gasket Kit P400270160067
ATHENA
$56.95Kits 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 required09343157- SKU:
- 09343157
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- BORE SIZE:
- 82,00 MM
- BORE SIZE METRIC:
- 82.00 MM
- DISPLACEMENT:
- 276 CC
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
$56.95Qty in Cart: 0Quantity:Price:$56.95Subtotal: -
ATHENA Top End Gasket Kit - Yamaha P400485600197
ATHENA
$57.95Specifically 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...09346215- SKU:
- 09346215
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- TYPE:
- TOP END
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$57.95Qty in Cart: 0Quantity:Price:$57.95Subtotal: -
ATHENA Complete Gasket Kit - Honda P400210900320
ATHENA
$209.95Head gaskets feature rubber-coated spring steel construction, Soft steel base gaskets are rubber coated, Steel core materials feature high spring-back and superior tensile strength, Revolutionary transparent coating guarantees a perfect seal even at...09346349- SKU:
- 09346349
- Availability:
- Ships Same Business Day
- Weight:
- 0.56 LBS
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- KIT
$209.95Qty in Cart: 0Quantity:Price:$209.95Subtotal:
