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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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 - 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 -
Cylinder Works Big Bore Cylinder Kit 295cc for Yamaha YZ250 1999-2023 21009-K01
CYLINDER WORKS
$1,255.75The 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
$1,255.75 -
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 -
ACERBIS X-Power Kit - Black - Husqvarna/KTM 2983230001
ACERBIS
$76.95Off-road riding exposes your engine to constant threats—mud, debris, sand, and extreme heat that can compromise critical components. The ACERBIS X-Power Kit delivers comprehensive protection for your...09402144- SKU:
- 09402144
- Availability:
- Ships Same Business Day
- Weight:
- 1.45 LBS
- MODEL:
- X-POWER
- COLOR/FINISH:
- BLACK
- MATERIAL:
- PLASTIC
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MATERIAL:
- STEEL
- PRODUCT NAME:
- X-POWER KIT
- TYPE:
- SIDE COVER
$76.95 -
ACERBIS X-Power Kit - Blue - Husqvarna/KTM 2983230003
ACERBIS
$76.95Off-road riding exposes your engine to constant abuse—flying rocks, mud, water, and extreme heat can damage critical components like your clutch cover, water pump, and ignition system. The ACERBIS...09402145- SKU:
- 09402145
- Availability:
- Ships Same Business Day
- Weight:
- 1.40 LBS
- COLOR/FINISH:
- BLUE
- MATERIAL:
- PLASTIC
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MODEL:
- X-POWER
- TYPE:
- SIDE COVER
- MATERIAL:
- STEEL
- PRODUCT NAME:
- X-POWER KIT
$76.95 -
ACERBIS X-Power Kit - Black - Honda CRF 2982510001
ACERBIS
$76.95Your crankcase and clutch housing face constant abuse from impact, abrasion, and debris—especially in off-road conditions. The ACERBIS X-Power Kit provides direct OEM-fitment protection engineered to...09402146- SKU:
- 09402146
- Availability:
- Ships Same Business Day
- Weight:
- 1.34 LBS
- MODEL:
- X-POWER
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- STREET
- UNITS:
- KIT
- MATERIAL:
- STEEL
- PRODUCT NAME:
- X-POWER KIT
- MATERIAL:
- NYLON
- TYPE:
- SIDE COVER
$76.95 -
ACERBIS X-Power Kit - Red - Honda CRF 2982510004
ACERBIS
$76.95Your crankcase and clutch housing face constant abuse from impacts, mud, sand, and debris—damage that translates to expensive repairs and downtime. The ACERBIS X-Power Kit provides OEM-fitted...09402147- SKU:
- 09402147
- Availability:
- Ships Same Business Day
- Weight:
- 1.40 LBS
- MATERIAL:
- STEEL
- PRODUCT NAME:
- X-POWER KIT
- UNITS:
- KIT
- COLOR/FINISH:
- RED
- RIDING STYLE:
- STREET
- MODEL:
- X-POWER
- MATERIAL:
- NYLON
- TYPE:
- SIDE COVER
$76.95 -
ACERBIS X-Power Kit - Orange - Husqvarna/KTM 2983235226
ACERBIS
$76.95Off-road riding exposes your engine to relentless punishment—mud, sand, rocks, and extreme heat all threaten critical components like your clutch cover, water pump, and ignition system. The ACERBIS...09402148- SKU:
- 09402148
- Availability:
- Ships Same Business Day
- Weight:
- 1.40 LBS
- COLOR/FINISH:
- ORANGE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MATERIAL:
- STEEL
- PRODUCT NAME:
- X-POWER KIT
- TYPE:
- SIDE COVER
- MATERIAL:
- PLASTIC
- MODEL:
- X-POWER
$76.95 -
ACERBIS X-Power Kit - Orange - Husqvarna/KTM 2981365226
ACERBIS
$76.95Dirt bikes experience relentless punishment from mud, sand, and debris—and your engine covers shouldn't be the weak link. The ACERBIS X-Power Kit delivers comprehensive protection for your clutch,...09402149- SKU:
- 09402149
- Availability:
- Ships Same Business Day
- Weight:
- 1.40 LBS
- MATERIAL:
- BRASS
- PRODUCT NAME:
- X-POWER KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COLOR/FINISH:
- ORANGE
- MODEL:
- X-POWER
- MATERIAL:
- NYLON
- TYPE:
- SIDE COVER
$76.95 -
ACERBIS X-Power Kit - Black - Husqvarna/KTM 2981360001
ACERBIS
$76.95If you're running a Husqvarna or KTM dirt bike, engine cover damage isn't just a cosmetic issue—it compromises protection for critical components like your clutch cover, water pump, and ignition...09402150- SKU:
- 09402150
- Availability:
- Ships Same Business Day
- Weight:
- 1.40 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MATERIAL:
- BRASS
- PRODUCT NAME:
- X-POWER KIT
- MATERIAL:
- NYLON
- MODEL:
- X-POWER
- TYPE:
- SIDE COVER
- COLOR/FINISH:
- BLACK
$76.95 -
ACERBIS X-Power Kit - Blue - Husqvarna/KTM 2981360003
ACERBIS
$76.95Dirt bike racing demands engine protection that actually performs under extreme conditions. The ACERBIS X-Power Kit shields your clutch cover, water pump, lower crankcase, and ignition system from...09402151- SKU:
- 09402151
- Availability:
- Ships Same Business Day
- Weight:
- 1.35 LBS
- MATERIAL:
- BRASS
- PRODUCT NAME:
- X-POWER KIT
- COLOR/FINISH:
- BLUE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MATERIAL:
- NYLON
- MODEL:
- X-POWER
- TYPE:
- SIDE COVER
$76.95 -
ACERBIS X-Power Kit - Orange - Husqvarna/KTM 2981475226
ACERBIS
$76.95Off-road riding subjects your engine to constant assault from mud, sand, and debris—a single uncovered section can lead to costly damage or catastrophic failure. The ACERBIS X-Power Kit provides...09402152- SKU:
- 09402152
- Availability:
- Ships Same Business Day
- Weight:
- 1.25 LBS
- COLOR/FINISH:
- ORANGE
- RIDING STYLE:
- STREET
- MATERIAL:
- BRASS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- X-POWER KIT
- TYPE:
- SIDE COVER
- MATERIAL:
- NYLON
- MODEL:
- X-POWER
$76.95 -
ACERBIS X-Power Kit - Black - Husqvarna/KTM 2981470001
ACERBIS
$76.95Off-road riding exposes your engine to constant punishment—mud, sand, rocks, and extreme temperatures degrade unprotected components quickly. The ACERBIS X-Power Kit shields your clutch cover, water...09402153- SKU:
- 09402153
- Availability:
- Ships Same Business Day
- Weight:
- 1.30 LBS
- MATERIAL:
- BRASS
- PRODUCT NAME:
- X-POWER KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- STREET
- MODEL:
- X-POWER
- MATERIAL:
- NYLON
- TYPE:
- SIDE COVER
$76.95 -
ACERBIS X-Power Kit - Blue - Husqvarna/KTM 2981470003
ACERBIS
$76.95If you're running a Husqvarna or KTM two-stroke, engine case protection isn't optional—it's essential. The ACERBIS X-Power Kit shields your clutch cover, water pump, lower crankcase, and ignition...09402154- SKU:
- 09402154
- Availability:
- Ships Same Business Day
- Weight:
- 0.65 LBS
- MODEL:
- X-POWER
- RIDING STYLE:
- STREET
- COLOR/FINISH:
- BLUE
- UNITS:
- KIT
- MATERIAL:
- BRASS
- PRODUCT NAME:
- X-POWER KIT
- RIDING STYLE:
- OFF-ROAD
- MATERIAL:
- NYLON
- TYPE:
- SIDE COVER
$76.95 -
ACERBIS X-Power Kit - Black - Yamaha YZ450F 2981870001
ACERBIS
$76.95Protect your YZ450F's most vulnerable components from the harsh realities of off-road riding. The ACERBIS X-Power Kit shields both your ignition and clutch crankcases from impacts, abrasion, and...09402156- SKU:
- 09402156
- Availability:
- Ships Same Business Day
- Weight:
- 1.40 LBS
- MATERIAL:
- NYLON
- MODEL:
- X-POWER
- COLOR/FINISH:
- BLACK
- MATERIAL:
- BRASS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- X-POWER KIT
- TYPE:
- SIDE COVER
$76.95 -
ACERBIS X-Power Kit - Blue - Yamaha YZ450F 2981870211
ACERBIS
$76.95Dirt bike racing demands protection against the constant barrage of mud, sand, and debris—especially on your YZ450F's vulnerable crankcase components. The ACERBIS X-Power Kit shields both your...09402157- SKU:
- 09402157
- Availability:
- Ships Same Business Day
- Weight:
- 1.46 LBS
- COLOR/FINISH:
- BLUE
- MODEL:
- X-POWER
- MATERIAL:
- NYLON
- TYPE:
- SIDE COVER
- MATERIAL:
- BRASS
- PRODUCT NAME:
- X-POWER KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$76.95 -
ACERBIS X-Power Kit - Black - Gas Gas/Husqvarna/KTM 2983260001
ACERBIS
$76.95When you're pushing your Gas Gas, Husqvarna, or KTM to its limits, unprotected engine covers become vulnerable to flying debris, mud, and impacts that can compromise critical components. The Acerbis...09402158- SKU:
- 09402158
- Availability:
- Ships Same Business Day
- Weight:
- 1.30 LBS
- TYPE:
- SIDE COVER
- MODEL:
- X-POWER
- RIDING STYLE:
- STREET
- COLOR/FINISH:
- BLACK
- MATERIAL:
- PLASTIC
- UNITS:
- KIT
- MATERIAL:
- STEEL
- PRODUCT NAME:
- X-POWER KIT
- RIDING STYLE:
- OFF-ROAD
$76.95
