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
PROX Gasket Kit - Complete - Yamaha 34.2221
PROX
MSRP: $74.95Now: $64.00Was: $74.95A complete gasket kit is essential for any top-end rebuild or full engine overhaul—it ensures proper sealing across all critical engine surfaces and prevents oil leaks, compression loss, and...09345547- SKU:
- 09345547
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
MSRP: $74.95Now: $64.00Was: $74.95Qty in Cart: 0Quantity:Price:MSRP: $74.95Now: $64.00Was: $74.95Subtotal: -
VERTEX Piston Kit - 76.95 mm - Kawasaki KX250F 24165A
VERTEX
$124.95Your KX250F's engine demands a piston that can handle the heat of competitive riding while maintaining the reliability you need for consistent performance. The VERTEX 76.95 mm Piston Kit delivers...09104669- SKU:
- 09104669
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
$124.95Qty in Cart: 0Quantity:Price:$124.95Subtotal: -
On Sale
Wiseco Wrist Pin for Honda CRF125F 2014-2021 S538
WISECO
MSRP: $22.99Now: $20.00Was: $22.99The wrist pin is a critical load-bearing component that directly transfers combustion forces from the piston to the connecting rod. A failing or worn wrist pin compromises engine reliability, reduces...S538- SKU:
- S538
- Availability:
- Ships Same Business Day
- Weight:
- 0.04 LBS
MSRP: $22.99Now: $20.00Was: $22.99Qty in Cart: 0Quantity:Price:MSRP: $22.99Now: $20.00Was: $22.99Subtotal: -
On Sale
Wiseco Piston Kit 95.00 mm Yamaha YZ450F 2006-2009 4694M09500
WISECO
MSRP: $269.95Now: $229.00Was: $269.95If you're rebuilding your YZ450F or pushing higher RPMs on the track, a worn or damaged piston directly kills power and reliability. This Wiseco forged piston kit restores compression, improves...09102919- SKU:
- 09102919
- Availability:
- Ships Same Business Day
- Weight:
- 0.70 LBS
MSRP: $269.95Now: $229.00Was: $269.95Qty in Cart: 0Quantity:Price:MSRP: $269.95Now: $229.00Was: $269.95Subtotal: -
On Sale
Wiseco Engine Rebuild Kit 66.40mm Bore Yamaha YZ250 2003-2020 PWR134-100
WISECO
MSRP: $710.95Now: $557.00Was: $710.95A worn or damaged YZ250 engine demands a complete rebuild to restore competitive performance and reliability. This Wiseco kit eliminates the guesswork by bundling OEM-specification components in one...09031519- SKU:
- 09031519
- Availability:
- Ships Same Business Day
- Weight:
- 13.30 LBS
MSRP: $710.95Now: $557.00Was: $710.95Qty in Cart: 0Quantity:Price:MSRP: $710.95Now: $557.00Was: $710.95Subtotal: -
WORKS CONNECTION Radiator Drain Plug - Black - Honda/Kawasaki 24-632
WORKS CONNECTION
$23.95Stock plastic radiator drain plugs fail when you need them most—corroded, stripped, or cracked mid-season. The WORKS CONNECTION billet aluminum drain plug eliminates this weak point with a...09500984- SKU:
- 09500984
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
$23.95Qty in Cart: 0Quantity:Price:$23.95Subtotal: -
WORKS CONNECTION Radiator Drain Plug - Green - Honda/Kawasaki 24-633
WORKS CONNECTION
$23.95Stock plastic radiator drain plugs fail when you need them most—corroding, cracking, or stripping threads under thermal stress. The WORKS CONNECTION billet aluminum drain plug eliminates this weak...09500985- SKU:
- 09500985
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
$23.95Qty in Cart: 0Quantity:Price:$23.95Subtotal: -
On Sale
Wossner 90.00mm Piston Ring Set for 4-Stroke Engines 900XSY-3
WOSSNER
MSRP: $38.95Now: $37.00Was: $38.95Piston rings are the critical seal between your piston and cylinder wall—without proper sealing, you lose compression, power, and efficiency. This Wossner ring set restores that seal to OEM...09120683- SKU:
- 09120683
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
MSRP: $38.95Now: $37.00Was: $38.95Qty in Cart: 0Quantity:Price:MSRP: $38.95Now: $37.00Was: $38.95Subtotal: -
On Sale
KIBBLEWHITE Valve - Intake - Tensilite 40-41612T
KIBBLEWHITE
MSRP: $92.51Now: $83.26Was: $92.51If you're serious about maximizing valve life and performance on your engine build, OEM intake valves simply won't cut it. Kibblewhite's Black Diamond intake valves are purpose-built from premium...09263389- SKU:
- 09263389
- Availability:
- Ships Same Business Day
- Weight:
- 0.21 LBS
MSRP: $92.51Now: $83.26Was: $92.51Qty in Cart: 0Quantity:Price:MSRP: $92.51Now: $83.26Was: $92.51Subtotal: -
MOOSE OFFROAD Carburetor Mid Body Gasket Kit - Honda 26-10157
MOOSE OFFROAD
$24.95A leaking or worn carburetor mid-body gasket can cause fuel seepage, inconsistent jetting, and performance loss—problems that compromise both reliability and rideability. The MOOSE OFFROAD Carburetor...09351198- SKU:
- 09351198
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
$24.95 -
MOOSE RACING Exhaust Valve M40-41660
MOOSE RACING
$196.95Stock exhaust valves wear out, compromise flow, and force costly rebuilds. The MOOSE RACING M40-41660 stainless steel exhaust valve extends valve train life up to 4x longer than OEM titanium while...09263372- SKU:
- 09263372
- Availability:
- Ships Same Business Day
- Weight:
- 0.42 LBS
$196.95 -
MOOSE RACING Intake Valve M30-34000
MOOSE RACING
$196.95Stock intake valves leave performance on the table—restricted flow, inconsistent sealing, and premature wear are common limitations in OEM designs. The MOOSE RACING M30-34000 Intake Valve addresses...09263373- SKU:
- 09263373
- Availability:
- Ships Same Business Day
- Weight:
- 0.51 LBS
$196.95Qty in Cart: 0Quantity:Price:$196.95Subtotal: -
On Sale
Wossner Crankshaft Assembly for KTM 85 SX 2014-2017 Husqvarna TC85 2014-2017 CS2065-1
WOSSNER
MSRP: $382.95Now: $324.90Was: $382.95A worn or damaged crankshaft directly impacts engine reliability, power delivery, and longevity—especially in high-RPM small-displacement engines like the KTM 85 SX and Husqvarna TC85. This complete...09210914- SKU:
- 09210914
- Availability:
- Ships Same Business Day
- Weight:
- 4.48 LBS
MSRP: $382.95Now: $324.90Was: $382.95Qty in Cart: 0Quantity:Price:MSRP: $382.95Now: $324.90Was: $382.95Subtotal: -
On Sale
Wossner Crankshaft Assembly Yamaha YZ85 2019-2025 CS2072
WOSSNER
MSRP: $262.00Now: $248.90Was: $262.00Your YZ85's crankshaft assembly is the heartbeat of engine performance—when it's worn or damaged, you lose power delivery, reliability, and overall rideability. The Wossner CS2072 restores your...09210917- SKU:
- 09210917
- Availability:
- Ships Same Business Day
- Weight:
- 4.06 LBS
MSRP: $262.00Now: $248.90Was: $262.00 -
On Sale
Wossner Crankshaft Assembly Yamaha YZ250F 2003-2013 CS4005
WOSSNER
MSRP: $404.00Now: $383.80Was: $404.00The crankshaft assembly is the heart of your YZ250F's engine—worn or damaged components here directly translate to lost power, increased friction, and premature failure. This Wossner assembly...09210919- SKU:
- 09210919
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
MSRP: $404.00Now: $383.80Was: $404.00Qty in Cart: 0Quantity:Price:MSRP: $404.00Now: $383.80Was: $404.00Subtotal: -
On Sale
VINTCO Connecting Rod Kit KR2003
VINTCO
MSRP: $170.95Now: $158.98Was: $170.95A connecting rod kit is the critical link between your crankshaft and pistons—and factory rods often represent the weakest point in a high-performance engine build. The VINTCO KR2003 delivers...09230635- SKU:
- 09230635
- Availability:
- Ships Same Business Day
- Weight:
- 0.71 LBS
MSRP: $170.95Now: $158.98Was: $170.95Qty in Cart: 0Quantity:Price:MSRP: $170.95Now: $158.98Was: $170.95Subtotal: -
On Sale
VINTCO Connecting Rod Kit KR2037
VINTCO
MSRP: $159.95Now: $148.75Was: $159.95A connecting rod kit is critical to engine reliability—it transfers combustion force from the piston to the crankshaft, so any weakness here compromises power delivery and engine longevity. The...09230637- SKU:
- 09230637
- Availability:
- Ships Same Business Day
- Weight:
- 0.71 LBS
MSRP: $159.95Now: $148.75Was: $159.95Qty in Cart: 0Quantity:Price:MSRP: $159.95Now: $148.75Was: $159.95Subtotal: -
On Sale
VINTCO Connecting Rod Kit KR2030
VINTCO
MSRP: $181.95Now: $169.21Was: $181.95A connecting rod failure can mean catastrophic engine damage and costly downtime. The VINTCO KR2030 delivers heavy-duty forged construction that handles the extreme pressures and reciprocating forces...09230662- SKU:
- 09230662
- Availability:
- Ships Same Business Day
- Weight:
- 1.06 LBS
MSRP: $181.95Now: $169.21Was: $181.95 -
On Sale
VINTCO Connecting Rod Kit KR2056
VINTCO
MSRP: $106.95Now: $99.46Was: $106.95A connecting rod kit is fundamental to engine reliability under high load and high RPM conditions. The VINTCO KR2056 delivers heavy-duty forged construction that meets or exceeds OEM specifications...09230665- SKU:
- 09230665
- Availability:
- Ships Same Business Day
- Weight:
- 1.01 LBS
MSRP: $106.95Now: $99.46Was: $106.95Qty in Cart: 0Quantity:Price:MSRP: $106.95Now: $99.46Was: $106.95Subtotal: -
On Sale
VINTCO Connecting Rod Kit KR2031
VINTCO
MSRP: $192.95Now: $179.44Was: $192.95A connecting rod failure mid-race can end your day—or worse, your engine. The VINTCO KR2031 is engineered to withstand extreme combustion pressures and sustained high RPM operation with forged...09230671- SKU:
- 09230671
- Availability:
- Ships Same Business Day
- Weight:
- 1.06 LBS
MSRP: $192.95Now: $179.44Was: $192.95
