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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JE PISTONS Piston Kit - 14.5:1 - Kawasaki 391920
JE PISTONS
$316.99If you're running a high-compression build or pushing your Kawasaki engine into professional competition territory, you need pistons engineered for the abuse. JE's 14.5:1 compression kit delivers the...09106680- SKU:
- 09106680
- Availability:
- Ships Same Business Day
- Weight:
- 0.78 LBS
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- RIDING STYLE:
- OFF-ROAD
- COMPRESSION RATIO IMPERIAL:
- 14.5:1
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
$316.99 -
On Sale
ATHENA Piston Kit with Gaskets - 95.97 mm - KX450F P5F0960072007A
ATHENA
MSRP: $263.07Now: $237.00Was: $263.07Stock pistons wear, lose compression, and rob you of the responsiveness your KX450F demands on technical terrain. This ATHENA piston kit restores full performance potential while engineering in...09031750- SKU:
- 09031750
- Availability:
- Ships Same Business Day
- Weight:
- 1.55 LBS
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE SIZE METRIC:
- 95.97 MM
- DISPLACEMENT:
- 450 CC
- TYPE:
- TOP END
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- MODEL:
- A
- PRODUCT NAME:
- PISTON KIT
MSRP: $263.07Now: $237.00Was: $263.07Qty in Cart: 0Quantity:Price:MSRP: $263.07Now: $237.00Was: $263.07Subtotal: -
On Sale
ATHENA Piston Kit with Gaskets - 95.95 mm - CRF450R P5F0960322006A
ATHENA
MSRP: $259.07Now: $233.00Was: $259.07A worn or stock piston limits your CRF450R's combustion efficiency and reliability—especially under sustained high-RPM riding or aggressive trail conditions. The ATHENA Piston Kit delivers...09031744- SKU:
- 09031744
- Availability:
- Ships Same Business Day
- Weight:
- 1.53 LBS
- BORE SIZE METRIC:
- 95.95 MM
- DISPLACEMENT:
- 450 CC
- PRODUCT NAME:
- PISTON KIT
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- PISTON MATERIAL:
- FORGED
- UNITS:
- KIT
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- A
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
MSRP: $259.07Now: $233.00Was: $259.07 -
On Sale
ATHENA Piston Kit with Gaskets - 95.96 mm - CRF450R P5F0960322006B
ATHENA
MSRP: $259.07Now: $233.00Was: $259.07A worn or damaged piston directly compromises your CRF450R's compression, power delivery, and engine longevity. The ATHENA Piston Kit delivers OE-equivalent reliability with superior wear resistance...09031745- SKU:
- 09031745
- Availability:
- Ships Same Business Day
- Weight:
- 1.55 LBS
- BORE SIZE METRIC:
- 95.96 MM
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- MODEL:
- B
- PRODUCT NAME:
- PISTON KIT
- DISPLACEMENT:
- 450 CC
- TYPE:
- TOP END
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
MSRP: $259.07Now: $233.00Was: $259.07Qty in Cart: 0Quantity:Price:MSRP: $259.07Now: $233.00Was: $259.07Subtotal: -
On Sale
ATHENA Piston Kit with Gaskets - 95.95 mm - CRF450R P5F0960320006A
ATHENA
MSRP: $261.07Now: $235.00Was: $261.07When your CRF450R's piston shows wear, combustion efficiency drops and power delivery suffers—this ATHENA piston kit restores that performance with precision-engineered components built to OEM...09031746- SKU:
- 09031746
- Availability:
- Ships Same Business Day
- Weight:
- 1.53 LBS
- BORE SIZE METRIC:
- 95.95 MM
- PRODUCT NAME:
- PISTON KIT
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- MODEL:
- A
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- DISPLACEMENT:
- 450 CC
- TYPE:
- TOP END
MSRP: $261.07Now: $235.00Was: $261.07 -
On Sale
ATHENA Piston Kit with Gaskets - 95.96 mm - CRF450R P5F0960320006B
ATHENA
MSRP: $261.07Now: $235.00Was: $261.07A worn or damaged piston directly compromises combustion efficiency, power output, and engine longevity—especially in high-demand off-road riding. The ATHENA 95.96 mm Piston Kit restores your CRF450R...09031747- SKU:
- 09031747
- Availability:
- Ships Same Business Day
- Weight:
- 1.50 LBS
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- PISTON MATERIAL:
- FORGED
- BORE SIZE METRIC:
- 95.96 MM
- DISPLACEMENT:
- 450 CC
- MODEL:
- B
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
MSRP: $261.07Now: $235.00Was: $261.07 -
On Sale
ATHENA Piston Kit with Gaskets - 95.97 mm - KX450F P5F0960068007A
ATHENA
MSRP: $265.02Now: $239.00Was: $265.02When you're pushing a KX450F to its limits, a worn or stock piston becomes your bottleneck—restricting flow, sapping power, and threatening reliability under sustained load. The ATHENA Piston Kit...09031752- SKU:
- 09031752
- Availability:
- Ships Same Business Day
- Weight:
- 1.50 LBS
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- A
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- DISPLACEMENT:
- 450 CC
- PRODUCT NAME:
- PISTON KIT
- BORE SIZE METRIC:
- 95.97 MM
- TYPE:
- TOP END
MSRP: $265.02Now: $239.00Was: $265.02 -
On Sale
ATHENA Piston Kit with Gaskets - 95.98 mm - KX450F P5F0960068007B
ATHENA
MSRP: $289.95Now: $239.00Was: $289.95A worn or damaged piston directly kills your engine's compression, throttle response, and overall reliability—especially critical in high-demand 4-stroke off-road applications. The ATHENA Piston Kit...09031753- SKU:
- 09031753
- Availability:
- Ships Same Business Day
- Weight:
- 1.51 LBS
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- DISPLACEMENT:
- 450 CC
- TYPE:
- TOP END
- MODEL:
- B
- PRODUCT NAME:
- PISTON KIT
- BORE SIZE METRIC:
- 95.98 MM
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
MSRP: $289.95Now: $239.00Was: $289.95 -
On Sale
ATHENA Piston Kit with Gaskets - 95.95 mm - KX450F P5F0960066002A
ATHENA
MSRP: $273.07Now: $246.00Was: $273.07When your KX450F is pushing peak RPMs on the track or trail, a worn piston compromises compression, power delivery, and engine longevity. The ATHENA Piston Kit delivers OE-equivalent reliability with...09031754- SKU:
- 09031754
- Availability:
- Ships Same Business Day
- Weight:
- 1.60 LBS
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- MODEL:
- A
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- BORE SIZE METRIC:
- 95.95 MM
- PRODUCT NAME:
- PISTON KIT
- DISPLACEMENT:
- 450 CC
- TYPE:
- TOP END
MSRP: $273.07Now: $246.00Was: $273.07 -
On Sale
ATHENA Piston Kit with Gaskets - 94.95 mm - SXF450 P5F0950081002A
ATHENA
MSRP: $269.95Now: $252.00Was: $269.95When you're pushing your SXF450 to its limits, your piston needs to deliver reliability under extreme heat and pressure. The ATHENA Piston Kit combines OE-equivalent durability with enhanced material...09031756- SKU:
- 09031756
- Availability:
- Ships Same Business Day
- Weight:
- 1.54 LBS
- BORE SIZE METRIC:
- 94.95 MM
- TYPE:
- TOP END
- UNITS:
- KIT
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- A
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- COMPRESSION RATIO IMPERIAL:
- 12.8:1
- PISTON MATERIAL:
- FORGED
- DISPLACEMENT:
- 449 CC
- RIDING STYLE:
- OFF-ROAD
MSRP: $269.95Now: $252.00Was: $269.95 -
On Sale
ATHENA Piston Kit with Gaskets - 94.96 mm - SXF450 P5F0950081001B
ATHENA
MSRP: $279.95Now: $252.00Was: $279.95If you're rebuilding a top-end on your 4-stroke off-road machine, piston selection directly impacts reliability under load and throttle response across the RPM band. The ATHENA Piston Kit delivers...09031759- SKU:
- 09031759
- Availability:
- Ships Same Business Day
- Weight:
- 1.54 LBS
- BORE SIZE METRIC:
- 94.96 MM
- DISPLACEMENT:
- 450 CC
- MODEL:
- B
- PRODUCT NAME:
- PISTON KIT
- PISTON MATERIAL:
- FORGED
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 12.6:1
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- TYPE:
- TOP END
MSRP: $279.95Now: $252.00Was: $279.95Qty in Cart: 0Quantity:Price:MSRP: $279.95Now: $252.00Was: $279.95Subtotal: -
On Sale
ATHENA Piston Kit with Gaskets - 87.96 mm - SXF350 P5F0880090001B
ATHENA
MSRP: $257.02Now: $231.00Was: $257.02If you're running a KTM SXF350 at the edge of its limits, piston wear directly impacts combustion efficiency, power delivery, and engine longevity. The ATHENA Piston Kit delivers OE-equivalent...09031761- SKU:
- 09031761
- Availability:
- Ships Same Business Day
- Weight:
- 1.38 LBS
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- PISTON KIT
- BORE SIZE METRIC:
- 87.96 MM
- COMPRESSION RATIO IMPERIAL:
- 14.2:1
- DISPLACEMENT:
- 349 CC
- TYPE:
- TOP END
- MODEL:
- B
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $257.02Now: $231.00Was: $257.02Qty in Cart: 0Quantity:Price:MSRP: $257.02Now: $231.00Was: $257.02Subtotal: -
On Sale
ATHENA Piston Kit with Gaskets - 87.96 mm - SXF350 P5F0880079001B
ATHENA
MSRP: $311.02Now: $280.00Was: $311.02A worn or damaged piston directly compromises combustion efficiency, throttle response, and engine longevity—particularly critical in 4-stroke off-road applications where reliability matters. The...09031763- SKU:
- 09031763
- Availability:
- Ships Same Business Day
- Weight:
- 1.39 LBS
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- COMPRESSION RATIO IMPERIAL:
- 14.2:1
- DISPLACEMENT:
- 349 CC
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- BORE SIZE METRIC:
- 87.96 MM
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
- MODEL:
- B
MSRP: $311.02Now: $280.00Was: $311.02Qty in Cart: 0Quantity:Price:MSRP: $311.02Now: $280.00Was: $311.02Subtotal: -
On Sale
ATHENA Piston Kit with Gaskets - 95.96 mm - RMZ450 P5F0960061004B
ATHENA
MSRP: $283.95Now: $256.00Was: $283.95Whether you're rebuilding after a season of hard racing or upgrading to restore lost compression, the ATHENA Piston Kit delivers the reliability you need without compromise. This Japanese-engineered...09031765- SKU:
- 09031765
- Availability:
- Ships Same Business Day
- Weight:
- 1.50 LBS
- BORE SIZE METRIC:
- 95.96 MM
- DISPLACEMENT:
- 450 CC
- MODEL:
- B
- PRODUCT NAME:
- PISTON KIT
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- ENGINE TYPE:
- 4-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- TOP END
MSRP: $283.95Now: $256.00Was: $283.95Qty in Cart: 0Quantity:Price:MSRP: $283.95Now: $256.00Was: $283.95Subtotal: -
On Sale
ATHENA Piston Kit with Gaskets - 96.95 mm - YZ450F P5F0970213005A
ATHENA
MSRP: $249.95Now: $225.00Was: $249.95OEM reliability meets measurable performance gains. The ATHENA Piston Kit delivers the durability you need for sustained high-RPM operation while reducing friction losses that cost you power. If...09031766- SKU:
- 09031766
- Availability:
- Ships Same Business Day
- Weight:
- 1.54 LBS
- BORE SIZE METRIC:
- 96.95 MM
- PRODUCT NAME:
- PISTON KIT
- COMPRESSION RATIO IMPERIAL:
- 13.7:1
- TYPE:
- TOP END
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- A
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- DISPLACEMENT:
- 449 CC
- PISTON MATERIAL:
- FORGED
- UNITS:
- KIT
MSRP: $249.95Now: $225.00Was: $249.95Qty in Cart: 0Quantity:Price:MSRP: $249.95Now: $225.00Was: $249.95Subtotal: -
On Sale
ATHENA Piston Kit with Gaskets - 96.96 mm - YZ450F P5F0970213005B
ATHENA
MSRP: $249.95Now: $225.00Was: $249.95Factory pistons wear out—especially under aggressive riding conditions—and a worn piston compromises compression, power delivery, and fuel efficiency. The ATHENA Piston Kit gives your YZ450F a...09031767- SKU:
- 09031767
- Availability:
- Ships Same Business Day
- Weight:
- 1.51 LBS
- COMPRESSION RATIO IMPERIAL:
- 13.7:1
- MODEL:
- B
- DISPLACEMENT:
- 449 CC
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- BORE SIZE METRIC:
- 96.96 MM
- PRODUCT NAME:
- PISTON KIT
- TYPE:
- TOP END
MSRP: $249.95Now: $225.00Was: $249.95Qty in Cart: 0Quantity:Price:MSRP: $249.95Now: $225.00Was: $249.95Subtotal: -
On Sale
ATHENA Piston Kit with Gaskets - 96.95 mm - YZ450F P5F0970197004A
ATHENA
MSRP: $289.95Now: $218.00Was: $289.95When your YZ450F's piston is nearing the end of its service life, installing OEM-equivalent replacement parts is critical to maintaining reliability and power delivery. This ATHENA piston kit...09031768- SKU:
- 09031768
- Availability:
- Ships Same Business Day
- Weight:
- 1.55 LBS
- TYPE:
- TOP END
- BORE SIZE METRIC:
- 96.95 MM
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- A
- PRODUCT NAME:
- PISTON KIT
- COMPRESSION RATIO IMPERIAL:
- 12.8:1
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- DISPLACEMENT:
- 450 CC
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $289.95Now: $218.00Was: $289.95 -
Hinson Racing Clutch Cover KTM 250 SX 2018-2022 C700-1801
HINSON RACING
$169.99Stock clutch covers on your 2018-2022 KTM 250 SX will eventually crack, warp, or lose their hard-coat finish under the demands of racing. The Hinson Racing Clutch Cover C700-1801 replaces that...09402142- SKU:
- 09402142
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
- MATERIAL:
- T-6 ALUMINUM
- COLOR/FINISH:
- BLACK
- PRODUCT NAME:
- COVER
- RIDING STYLE:
- STREET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
- UNITS:
- EACH
$169.99Qty in Cart: 0Quantity:Price:$169.99Subtotal: -
Cylinder Works Big Bore Cylinder Kit 295cc for Yamaha YZ250 1999-2023 21009-K01
CYLINDER WORKS
$1,195.95The Cylinder Works Big Bore Kit transforms your YZ250 into a more potent machine by increasing displacement to 295cc—delivering measurable gains in mid-range and peak power without sacrificing the...09311163- SKU:
- 09311163
- Availability:
- Ships Same Business Day
- Weight:
- 8.71 LBS
- COLOR/FINISH:
- GRAY
- CYLINDER DIAMETER:
- 72,00 MM
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- CYLINDER DIAMETER METRIC:
- 72.00 MM
- DISPLACEMENT:
- 295 CC
- OVERBORE METRIC:
- +5.60 MM
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
$1,195.95 -
ACERBIS X-Power Kit - Black - Suzuki 2983330001
ACERBIS
$76.95Crankcase damage from crashes or overheating can sideline your bike and drain your wallet. The ACERBIS X-Power Kit provides comprehensive protection for both your clutch and ignition crankcases while...09402143- SKU:
- 09402143
- Availability:
- Ships Same Business Day
- Weight:
- 1.47 LBS
- COLOR/FINISH:
- BLACK
- MATERIAL:
- METAL
- MATERIAL:
- PLASTIC
- RIDING STYLE:
- STREET
- MODEL:
- X-POWER
- TYPE:
- SIDE COVER
- PRODUCT NAME:
- X-POWER KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$76.95
