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 - 44.46 mm - Kawasaki P4C0445008001B
ATHENA
MSRP: $115.95Now: $104.00Was: $115.95If you're running a 2-stroke off-road machine, piston wear directly impacts compression, power delivery, and engine longevity. The ATHENA Piston Kit delivers OE-equivalent reliability while improving...09031783- SKU:
- 09031783
- Availability:
- Ships Same Business Day
- Weight:
- 0.77 LBS
MSRP: $115.95Now: $104.00Was: $115.95Qty in Cart: 0Quantity:Price:MSRP: $115.95Now: $104.00Was: $115.95Subtotal: -
On Sale
ATHENA Piston Kit with Gaskets - 53.96 mm - Yamaha P4C0540118014B
ATHENA
MSRP: $153.95Now: $131.00Was: $153.95When you're pushing a 2-stroke off-road engine to its limits, piston reliability becomes non-negotiable. The ATHENA Piston Kit delivers OE-level dependability with measurably improved durability and...09031787- SKU:
- 09031787
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
MSRP: $153.95Now: $131.00Was: $153.95 -
On Sale
PROX Cam Chain - T106ER - 110 Links - Gas Gas | Husqvarna | KTM 31.6356
PROX
MSRP: $88.95Now: $72.00Was: $88.95A worn or failing cam chain compromises valve timing precision and can lead to catastrophic engine damage if it breaks during operation. The PROX T106ER delivers OEM-equivalent reliability with...09251201- SKU:
- 09251201
- Availability:
- Ships Same Business Day
- Weight:
- 0.54 LBS
MSRP: $88.95Now: $72.00Was: $88.95 -
On Sale
PROX Cam Chain - 98XRH2010 - 114 Links - Yamaha 31.2414
PROX
MSRP: $77.95Now: $64.00Was: $77.95A worn or damaged cam chain compromises valve timing precision and can lead to catastrophic engine failure. The PROX 98XRH2010 delivers OEM-spec reliability with enhanced durability through advanced...09250825- SKU:
- 09250825
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
MSRP: $77.95Now: $64.00Was: $77.95 -
VERTEX Engine Rebuild Kit - Husqvarna | KTM WR00071
VERTEX
$1,225.95A complete engine rebuild demands precision components working in harmony—this kit eliminates guesswork by bundling all critical internal parts into one professionally-curated package. Whether you're...09031805- SKU:
- 09031805
- Availability:
- Ships Same Business Day
- Weight:
- 14.54 LBS
$1,225.95Qty in Cart: 0Quantity:Price:$1,225.95Subtotal: -
On Sale
BOLT Oil Change Hardware Kit - Honda OILCHG-CRF.2
BOLT
MSRP: $7.99Now: $7.19Was: $7.99Proper oil change intervals are non-negotiable for engine longevity, and using OEM-specification hardware ensures a reliable seal every time. This kit eliminates the hassle of sourcing individual...07120671- SKU:
- 07120671
- Availability:
- Ships Same Business Day
- Weight:
- 0.03 LBS
MSRP: $7.99Now: $7.19Was: $7.99 -
Hot Cams Manual Cam Chain Tensioner for KTM 250 SX-F 2005-2023 HC00146
HOT CAMS
$46.95A worn or improperly tensioned cam chain will cause timing drift, increased noise, and accelerated wear on your top-end—all of which compromise both performance and engine longevity. The Hot Cams...09251602- SKU:
- 09251602
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
$46.95 -
VERTEX Top End Piston Kit - 66.35 mm - Gas Gas | Husqvarna | KTM VTK23630B-3
VERTEX
$307.95When your top end starts showing signs of wear—whether it's lost compression, increased blow-by, or sluggish throttle response—a quality piston kit is essential to restore your bike's original...09106822- SKU:
- 09106822
- Availability:
- Ships Same Business Day
- Weight:
- 1.30 LBS
$307.95 -
On Sale
WOSSNER Piston Kit - 53.95 mm - Yamaha 8321DA
WOSSNER
MSRP: $132.00Now: $125.40Was: $132.00High-revving engines demand pistons engineered for precision and durability. WOSSNER's aerospace-grade forged construction delivers the strength needed for sustained performance while their permanent...09106837- SKU:
- 09106837
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
MSRP: $132.00Now: $125.40Was: $132.00Qty in Cart: 0Quantity:Price:MSRP: $132.00Now: $125.40Was: $132.00Subtotal: -
On Sale
Wossner Piston Kit 94.95 mm Husqvarna FC450 2023-2024 4097DA
WOSSNER
MSRP: $214.00Now: $203.30Was: $214.00When your FC450 demands peak performance, a worn or stock piston becomes your limiting factor. The Wossner 94.95 mm Piston Kit delivers the precision engineering and durability required to sustain...09106845- SKU:
- 09106845
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
MSRP: $214.00Now: $203.30Was: $214.00Qty in Cart: 0Quantity:Price:MSRP: $214.00Now: $203.30Was: $214.00Subtotal: -
VERTEX Top End Gasket Kit - Gas Gas/Husqvarna/KTM 810991
VERTEX
$101.25A leaking or deteriorating top-end gasket can silently drain your engine's performance and lead to costly damage if left unchecked. This VERTEX gasket kit delivers OEM-quality sealing across all...09348014- SKU:
- 09348014
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
$101.25 -
BOYESEN Water Pump Kit - Magnesium - Gas Gas/Husqvarna/KTM WPK-42M
BOYESEN
$194.95A reliable water pump is critical to maintaining optimal engine temperatures under sustained high-RPM operation, and the BOYESEN Magnesium Water Pump Kit delivers OEM-quality cooling performance with...09320309- SKU:
- 09320309
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
$194.95Qty in Cart: 0Quantity:Price:$194.95Subtotal: -
On Sale
ATHENA Piston Kit with Gaskets - 95.98 mm - KX450F P5F0960072007B
ATHENA
MSRP: $263.07Now: $237.00Was: $263.07The ATHENA Piston Kit delivers the reliability you expect from OEM-quality engineering while pushing performance beyond stock limitations. Precision-engineered with high-silicon aluminum alloy and...09031751- SKU:
- 09031751
- Availability:
- Ships Same Business Day
- Weight:
- 1.53 LBS
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- TYPE:
- TOP END
- DISPLACEMENT:
- 450 CC
- MODEL:
- B
- PRODUCT NAME:
- PISTON KIT
- BORE SIZE METRIC:
- 95.98 MM
- PISTON MATERIAL:
- FORGED
- UNITS:
- 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 - 87.95 mm - SXF350 P5F0880090001A
ATHENA
MSRP: $257.02Now: $231.00Was: $257.02Factory piston kits wear out and lose efficiency—upgrade to the ATHENA 87.95 mm to restore top-end power and extend engine life. This precision-engineered piston kit is built for 4-stroke off-road...09031760- SKU:
- 09031760
- Availability:
- Ships Same Business Day
- Weight:
- 1.36 LBS
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- BORE SIZE METRIC:
- 87.95 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 14.2:1
- DISPLACEMENT:
- 349 CC
- TYPE:
- TOP END
- MODEL:
- A
- PRODUCT NAME:
- PISTON 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 - 96.96 mm - YZ450F P5F0970197004B
ATHENA
MSRP: $229.95Now: $207.00Was: $229.95When your YZ450F's piston reaches the end of its service life, settling for a standard replacement means accepting compromised ring sealing and unnecessary friction losses. The ATHENA Piston Kit...09031769- SKU:
- 09031769
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- TYPE:
- TOP END
- UNITS:
- KIT
- DISPLACEMENT:
- 450 CC
- MODEL:
- B
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 96.96 MM
- COMPRESSION RATIO IMPERIAL:
- 12.8:1
- PISTON MATERIAL:
- FORGED
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
MSRP: $229.95Now: $207.00Was: $229.95Qty in Cart: 0Quantity:Price:MSRP: $229.95Now: $207.00Was: $229.95Subtotal: -
MOOSE RACING Piston Kit MX1026
MOOSE RACING
$0.00If you're pushing your engine to the limit, a stock piston won't cut it—especially under sustained high RPM or forced induction. The MOOSE RACING Piston Kit MX1026 is engineered to handle extreme...9106488- SKU:
- 9106488
- Availability:
- Ships Same Business Day
- Weight:
- 18.40 LBS
$0.00Qty in Cart: 0Quantity:Price:$0.00Subtotal: -
MOOSE RACING Piston Kit MPX2082
MOOSE RACING
$0.00When you're pushing your engine to its limits, stock pistons simply won't cut it. The MOOSE RACING Piston Kit MPX2082 delivers race-proven durability and reduced friction through precision X-style...9106518- SKU:
- 9106518
- Availability:
- Ships Same Business Day
- Weight:
- 12.80 LBS
$0.00Qty in Cart: 0Quantity:Price:$0.00Subtotal: -
MOOSE RACING Piston Kit MPX2083A-P
MOOSE RACING
$0.00If you're pushing your engine to its limits, stock pistons won't cut it. The MOOSE RACING Piston Kit MPX2083A-P is engineered with X-style and fully-boxed race forgings that deliver the strength,...9106519- SKU:
- 9106519
- Availability:
- Ships Same Business Day
- Weight:
- 12.80 LBS
$0.00Qty in Cart: 0Quantity:Price:$0.00Subtotal: -
MOOSE RACING Piston Kit MPX2059
MOOSE RACING
$0.00Whether you're chasing lap records or rebuilding after a catastrophic failure, piston reliability is non-negotiable. The MOOSE RACING Piston Kit MPX2059 combines race-proven forging technology with...9106487- SKU:
- 9106487
- Availability:
- Ships Same Business Day
- Weight:
- 17.60 LBS
$0.00Qty in Cart: 0Quantity:Price:$0.00Subtotal: -
MOOSE RACING Piston Kit MP3031C
MOOSE RACING
$0.00High-RPM racing demands pistons engineered to handle extreme cylinder pressures without sacrificing reliability. The MOOSE RACING Piston Kit MP3031C delivers race-proven forging technology with...9106484- SKU:
- 9106484
- Availability:
- Ships Same Business Day
- Weight:
- 12.80 LBS
$0.00Qty in Cart: 0Quantity:Price:$0.00Subtotal:
