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!
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- Qty in Cart
- Quantity
- Price
- Subtotal
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On Sale
Wossner Piston Kit 89.42mm Honda CR500R 1985-2001 8229D050
WOSSNER
MSRP: $192.00Now: $182.40Was: $192.00Stock pistons limit your Honda CR500R's potential—they can't withstand the demands of aggressive riding or consistent high-RPM operation. The Wossner 89.42mm Piston Kit delivers the strength and...09106643- SKU:
- 09106643
- Availability:
- Ships Same Business Day
- Weight:
- 1.18 LBS
MSRP: $192.00Now: $182.40Was: $192.00 -
On Sale
Wossner Piston Kit 89.92mm Honda CR500R 1985-2001 8229D100
WOSSNER
MSRP: $192.00Now: $182.40Was: $192.00If you're running a Honda CR500R, your piston kit directly determines how much power you can reliably extract from your engine—and whether that power translates to consistent performance across the...09106644- SKU:
- 09106644
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
MSRP: $192.00Now: $182.40Was: $192.00Qty in Cart: 0Quantity:Price:MSRP: $192.00Now: $182.40Was: $192.00Subtotal: -
On Sale
Wossner Piston Kit 88.92mm Honda CR500R 1984-2001 8229DA
WOSSNER
MSRP: $192.00Now: $182.40Was: $192.00If you're running a Honda CR500R and want reliable power delivery without sacrificing durability, a quality piston kit is non-negotiable. This Wossner unit maintains consistent compression and...09106645- SKU:
- 09106645
- Availability:
- Ships Same Business Day
- Weight:
- 1.17 LBS
MSRP: $192.00Now: $182.40Was: $192.00 -
On Sale
Wossner Performance Connecting Rod Kit Yamaha YZ65 2018-2025 P2071-R
WOSSNER
MSRP: $242.00Now: $229.90Was: $242.00The connecting rod is the critical link between your piston and crankshaft—any weakness here directly compromises engine reliability and peak performance. Wossner's P2071-R kit delivers 8620 forged...09230684- SKU:
- 09230684
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
MSRP: $242.00Now: $229.90Was: $242.00 -
On Sale
Wossner Connecting Rod Kit Yamaha YZ250 2001-2023 P2072
WOSSNER
MSRP: $112.00Now: $106.40Was: $112.00The connecting rod is the critical link between your crankshaft and piston—any flex or failure here directly kills power delivery and risks catastrophic engine damage. Wossner's P2072 kit is...09230685- SKU:
- 09230685
- Availability:
- Ships Same Business Day
- Weight:
- 0.60 LBS
MSRP: $112.00Now: $106.40Was: $112.00 -
On Sale
Wossner Connecting Rod Kit Yamaha YZ85 2019-2025 P2072-R
WOSSNER
MSRP: $242.00Now: $229.90Was: $242.00A connecting rod is the critical link between your piston and crankshaft—it endures extreme pressure and temperature cycles on every stroke. This Wossner kit for the YZ85 uses 8620 forged alloy and...09230686- SKU:
- 09230686
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
MSRP: $242.00Now: $229.90Was: $242.00 -
On Sale
Wossner Connecting Rod Kit Beta RR 250 2013-2017 P2069
WOSSNER
MSRP: $122.00Now: $115.90Was: $122.00A connecting rod kit is critical to engine reliability, especially in high-RPM or competitive riding environments where stock components can fail under sustained stress. The Wossner P2069 is...09230687- SKU:
- 09230687
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
MSRP: $122.00Now: $115.90Was: $122.00 -
On Sale
Wossner Connecting Rod Kit Beta RR250 2018-2021 P2073
WOSSNER
MSRP: $122.00Now: $115.90Was: $122.00If you're running a Beta RR250 at the limits of its capability, your connecting rod is working as hard as your engine. This Wössner kit replaces wear-prone OEM components with forged 8620 alloy rods...09230688- SKU:
- 09230688
- Availability:
- Ships Same Business Day
- Weight:
- 1.06 LBS
MSRP: $122.00Now: $115.90Was: $122.00Qty in Cart: 0Quantity:Price:MSRP: $122.00Now: $115.90Was: $122.00Subtotal: -
On Sale
Wossner Piston Kit 53.96mm Yamaha YZ125 2022-2025 8321DB
WOSSNER
MSRP: $132.00Now: $125.40Was: $132.00A worn or damaged piston directly compromises combustion efficiency, throttle response, and engine longevity—especially critical in a high-revving two-stroke like the YZ125. The Wossner 8321DB...09106610- SKU:
- 09106610
- Availability:
- Ships Same Business Day
- Weight:
- 0.41 LBS
MSRP: $132.00Now: $125.40Was: $132.00 -
On Sale
Wossner Piston Kit 53.97mm Yamaha YZ125 2022-2024 8321DC
WOSSNER
MSRP: $132.00Now: $125.40Was: $132.00If you're running a YZ125 at the limit, piston wear becomes your enemy—compromising combustion efficiency, increasing blow-by, and shortening engine life. This Wossner kit replaces worn internals...09106611- SKU:
- 09106611
- Availability:
- Ships Same Business Day
- Weight:
- 0.42 LBS
MSRP: $132.00Now: $125.40Was: $132.00Qty in Cart: 0Quantity:Price:MSRP: $132.00Now: $125.40Was: $132.00Subtotal: -
On Sale
Wossner 47.01 mm Cylinder for KTM 85 SX 2018-2024 WBC8147B
WOSSNER
MSRP: $452.00Now: $429.40Was: $452.00Stock 85cc cylinders wear quickly under racing conditions, limiting your power output and forcing costly rebuilds. The Wossner 47.01mm cylinder replaces that weakness with aerospace-grade...09311111- SKU:
- 09311111
- Availability:
- Ships Same Business Day
- Weight:
- 2.12 LBS
MSRP: $452.00Now: $429.40Was: $452.00Qty in Cart: 0Quantity:Price:MSRP: $452.00Now: $429.40Was: $452.00Subtotal: -
On Sale
Wossner Cylinder 47.00 mm KTM 85SX 2018-2025 WBC8147A
WOSSNER
MSRP: $452.00Now: $429.40Was: $452.00A worn or damaged cylinder directly impacts your 85's power delivery, throttle response, and fuel efficiency. The Wossner 47.00mm cylinder restores—or exceeds—OEM performance through precision...09311110- SKU:
- 09311110
- Availability:
- Ships Same Business Day
- Weight:
- 2.12 LBS
MSRP: $452.00Now: $429.40Was: $452.00Qty in Cart: 0Quantity:Price:MSRP: $452.00Now: $429.40Was: $452.00Subtotal: -
On Sale
ATHENA Piston Kit with Gaskets - 78.95 mm - CRF250R P5F0790323002A
ATHENA
MSRP: $269.95Now: $199.00Was: $269.95A worn or damaged piston directly undermines engine efficiency, power delivery, and reliability—especially critical in off-road riding where engine stress is constant. This ATHENA Piston Kit restores...09031736- SKU:
- 09031736
- Availability:
- Ships Same Business Day
- Weight:
- 1.20 LBS
MSRP: $269.95Now: $199.00Was: $269.95Qty in Cart: 0Quantity:Price:MSRP: $269.95Now: $199.00Was: $269.95Subtotal: -
On Sale
ATHENA Piston Kit with Gaskets - 78.96 mm - CRF250R P5F0790323002B
ATHENA
MSRP: $269.95Now: $199.00Was: $269.95A worn or damaged piston directly impacts your CRF250R's compression, power delivery, and engine longevity. This ATHENA piston kit restores OE-equivalent reliability while delivering the durability...09031738- SKU:
- 09031738
- Availability:
- Ships Same Business Day
- Weight:
- 1.21 LBS
MSRP: $269.95Now: $199.00Was: $269.95Qty in Cart: 0Quantity:Price:MSRP: $269.95Now: $199.00Was: $269.95Subtotal: -
On Sale
ATHENA Piston Kit with Gaskets - 77.96 mm - KX250F P5F0780071004A
ATHENA
MSRP: $289.95Now: $225.00Was: $289.95A worn or damaged piston directly impacts combustion efficiency, throttle response, and engine longevity—especially in high-demand off-road conditions. The ATHENA Piston Kit delivers OEM-exceeding...09031739- SKU:
- 09031739
- Availability:
- Ships Same Business Day
- Weight:
- 1.17 LBS
MSRP: $289.95Now: $225.00Was: $289.95 -
On Sale
ATHENA Piston Kit with Gaskets - 77.97 mm - KX250F P5F0780071004B
ATHENA
MSRP: $289.95Now: $225.00Was: $289.95When your stock piston starts showing wear, combustion efficiency drops and power delivery suffers. The ATHENA Piston Kit restores—and exceeds—OE performance with a high-silicon aluminum alloy...09031740- SKU:
- 09031740
- Availability:
- Ships Same Business Day
- Weight:
- 1.18 LBS
MSRP: $289.95Now: $225.00Was: $289.95 -
On Sale
ATHENA Piston Kit with Gaskets - 76.95 mm - RMZ250 P5F0770099004A
ATHENA
MSRP: $227.95Now: $205.00Was: $227.95A worn or stock piston kit limits your RMZ250's potential for sustained high-RPM performance and reliability. This ATHENA Piston Kit delivers the precision engineering and durable materials needed...09031741- SKU:
- 09031741
- Availability:
- Ships Same Business Day
- Weight:
- 1.09 LBS
MSRP: $227.95Now: $205.00Was: $227.95Qty in Cart: 0Quantity:Price:MSRP: $227.95Now: $205.00Was: $227.95Subtotal: -
ACERBIS X-Power Kit - Black - Honda 2983680001
ACERBIS
$76.95Off-road riding exposes your engine to relentless punishment—mud, debris, rocks, and extreme temperatures. The ACERBIS X-Power Kit shields your engine's most vulnerable components with purpose-built...09402161- SKU:
- 09402161
- Availability:
- Ships Same Business Day
- Weight:
- 2.15 LBS
$76.95 -
On Sale
PROX Crankshaft Oil Seal Set - Kawasaki 42.4351
PROX
MSRP: $25.95Now: $21.00Was: $25.95A failing crankshaft oil seal is a silent killer—it allows oil to seep past critical bearing surfaces, risking catastrophic engine damage and costly rebuilds. The PROX Crankshaft Oil Seal Set...09351278- SKU:
- 09351278
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
MSRP: $25.95Now: $21.00Was: $25.95 -
On Sale
PROX Crankshaft Oil Seal Set - Beta 42.7218
PROX
MSRP: $22.95Now: $17.00Was: $22.95Crankshaft oil seals are critical barriers against oil leakage and contamination—worn or failed seals compromise engine efficiency and can lead to costly damage. The PROX 42.7218 set delivers...09351279- SKU:
- 09351279
- Availability:
- Ships Same Business Day
- Weight:
- 0.04 LBS
MSRP: $22.95Now: $17.00Was: $22.95
