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Dirt Bike Engine

Dirt Bike Engine

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
  • MOOSE RACING Motor Gasket Kit with Seal - TTR125 811640

    MOOSE RACING Motor Gasket Kit with Seal - TTR125 811640

    MOOSE RACING

    $88.62
    A complete engine and transmission rebuild demands precision gaskets and seals that won't compromise your investment or performance. MOOSE Racing delivers OEM-equivalent fitment at a fraction of the...
    09340490
    SKU:
    09340490
    Availability:
    Ships Same Business Day
    Weight:
    0.20 LBS
    $88.62
    Qty in Cart: 0
    Quantity:
    Price:
    $88.62
    Subtotal:
  • MOOSE RACING Top End Gasket Kit - YZ125 810641

    MOOSE RACING Top End Gasket Kit - YZ125 810641

    MOOSE RACING

    $28.10
    A top-end rebuild demands precision gaskets and seals that won't compromise your engine's integrity or your wallet. The MOOSE RACING Top End Gasket Kit gives you OEM-quality components at a fraction...
    09340491
    SKU:
    09340491
    Availability:
    Ships Same Business Day
    Weight:
    0.07 LBS
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    KIT
    TYPE:
    TOP END
    PRODUCT NAME:
    GASKET
    $28.10
    Qty in Cart: 0
    Quantity:
    Price:
    $28.10
    Subtotal:
  • MOOSE RACING Slave Cylinder Rebuild Kit 18-6012

    MOOSE RACING Slave Cylinder Rebuild Kit 18-6012

    MOOSE RACING

    $73.95
    A leaking slave cylinder doesn't just waste hydraulic fluid—it compromises clutch engagement and leaves you stranded. This MOOSE RACING rebuild kit gives you everything needed to restore a sealing...
    09500897
    SKU:
    09500897
    Availability:
    Ships Same Business Day
    Weight:
    0.12 LBS
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    KIT
    RIDING STYLE:
    STREET
    PRODUCT NAME:
    REBUILD KIT
    TYPE:
    SLAVE CYLINDER
    $73.95
    Qty in Cart: 0
    Quantity:
    Price:
    $73.95
    Subtotal:
  • MOOSE RACING Slave Cylinder Rebuild Kit 18-6013

    MOOSE RACING Slave Cylinder Rebuild Kit 18-6013

    MOOSE RACING

    $72.95
    A leaking slave cylinder compromises brake feel and can leave you stranded on track or trail. This MOOSE RACING rebuild kit gives you everything needed to restore a worn slave cylinder to like-new...
    09500898
    SKU:
    09500898
    Availability:
    Ships Same Business Day
    Weight:
    0.15 LBS
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    KIT
    PRODUCT NAME:
    REBUILD KIT
    TYPE:
    SLAVE CYLINDER
    RIDING STYLE:
    STREET
    $72.95
    Qty in Cart: 0
    Quantity:
    Price:
    $72.95
    Subtotal:
  • MOOSE RACING Slave Cylinder Rebuild Kit - KTM 18-6004

    MOOSE RACING Slave Cylinder Rebuild Kit - KTM 18-6004

    MOOSE RACING

    $44.95
    A leaking slave cylinder compromises clutch control and can strand you trackside or on the trail. This MOOSE RACING rebuild kit restores your hydraulic seal integrity with OEM-quality components,...
    09500763
    SKU:
    09500763
    Availability:
    Ships Same Business Day
    Weight:
    0.10 LBS
    TYPE:
    SLAVE CYLINDER
    RIDING STYLE:
    OFF-ROAD
    PRODUCT NAME:
    REBUILD KIT
    UNITS:
    KIT
    $44.95
    Qty in Cart: 0
    Quantity:
    Price:
    $44.95
    Subtotal:
  • MOOSE RACING Slave Cylinder Rebuild Kit 18-6006

    MOOSE RACING Slave Cylinder Rebuild Kit 18-6006

    MOOSE RACING

    $44.95
    A leaking slave cylinder compromises brake feel, reduces pedal responsiveness, and puts your safety at risk—whether you're on the track or the street. The MOOSE RACING Slave Cylinder Rebuild Kit...
    09500765
    SKU:
    09500765
    Availability:
    Ships Same Business Day
    Weight:
    0.06 LBS
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    KIT
    PRODUCT NAME:
    REBUILD KIT
    TYPE:
    SLAVE CYLINDER
    $44.95
    Qty in Cart: 0
    Quantity:
    Price:
    $44.95
    Subtotal:
  • MOOSE RACING Slave Cylinder Rebuild Kit - KTM 18-6008

    MOOSE RACING Slave Cylinder Rebuild Kit - KTM 18-6008

    MOOSE RACING

    $44.95
    A leaking slave cylinder compromises braking feel, reduces stopping power, and can leave you stranded on track or trail. This complete MOOSE RACING rebuild kit restores your hydraulic system to OEM...
    09500767
    SKU:
    09500767
    Availability:
    Ships Same Business Day
    Weight:
    0.16 LBS
    PRODUCT NAME:
    REBUILD KIT
    TYPE:
    SLAVE CYLINDER
    UNITS:
    KIT
    RIDING STYLE:
    OFF-ROAD
    $44.95
    Qty in Cart: 0
    Quantity:
    Price:
    $44.95
    Subtotal:
  • MOOSE RACING Slave Cylinder Rebuild Kit 18-6009

    MOOSE RACING Slave Cylinder Rebuild Kit 18-6009

    MOOSE RACING

    $44.95
    A leaking slave cylinder compromises brake feel and can leave you stranded. This complete rebuild kit from MOOSE RACING provides all the OEM-specification seals and components needed to restore your...
    09500768
    SKU:
    09500768
    Availability:
    Ships Same Business Day
    Weight:
    0.06 LBS
    TYPE:
    SLAVE CYLINDER
    PRODUCT NAME:
    REBUILD KIT
    RIDING STYLE:
    ADVENTURE TOURING / DUAL-SPORT
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    KIT
    $44.95
    Qty in Cart: 0
    Quantity:
    Price:
    $44.95
    Subtotal:
  • WSM Rotary Valve Gear 010-450

    WSM Rotary Valve Gear 010-450

    WSM

    $45.26
    If your Sea-Doo's rotary valve isn't operating at peak efficiency, power delivery and throttle response suffer—and so does your watercraft's overall performance. The WSM Rotary Valve Gear 010-450 is...
    010450
    SKU:
    010450
    Availability:
    Ships Same Business Day
    Weight:
    0.10 LBS
    UNITS:
    EACH
    PRODUCT NAME:
    GEAR
    RIDING STYLE:
    WATERCRAFT
    TYPE:
    ROTARY VALVE
    $45.26
    Qty in Cart: 0
    Quantity:
    Price:
    $45.26
    Subtotal:
  • WSM Rotary Valve Shaft 010-455

    WSM Rotary Valve Shaft 010-455

    WSM

    $86.94
    The WSM Rotary Valve Shaft 010-455 is essential for maintaining precise intake timing and fuel delivery in your Sea-Doo engine. A worn or damaged rotary valve shaft compromises performance and can...
    010455
    SKU:
    010455
    Availability:
    Ships Same Business Day
    Weight:
    0.40 LBS
    MATERIAL:
    STEEL
    PRODUCT NAME:
    SHAFT
    RIDING STYLE:
    WATERCRAFT
    TYPE:
    ROTARY VALVE
    UNITS:
    EACH
    $86.94
    Qty in Cart: 0
    Quantity:
    Price:
    $86.94
    Subtotal:
  • WSM Top-End Rebuild Kit - Original Series - Standard 010-802-10

    WSM Top-End Rebuild Kit - Original Series - Standard 010-802-10

    WSM

    $247.87
    A top-end rebuild is essential maintenance for any high-performance engine, and the WSM Original Series kit delivers OEM-quality components at a fraction of full-engine rebuild costs. This...
    01080210
    SKU:
    01080210
    Availability:
    Ships Same Business Day
    Weight:
    2.60 LBS
    BORE - OVERSIZE METRIC:
    STANDARD
    PRODUCT NAME:
    REBUILD KIT
    UNITS:
    EACH
    BORE SIZE METRIC:
    77.00 MM
    MODEL:
    ORIGINAL SERIES
    TYPE:
    TOP END
    BORE - OVERSIZE:
    STANDARD
    RIDING STYLE:
    WATERCRAFT
    PISTON MATERIAL:
    ALUMINUM
    $247.87
    Qty in Cart: 0
    Quantity:
    Price:
    $247.87
    Subtotal:
  • WSM Top-End Rebuild Kit - Original Series - .50 mm 010-802-12

    WSM Top-End Rebuild Kit - Original Series - .50 mm 010-802-12

    WSM

    $247.87
    A top-end rebuild is fundamental to restoring your engine's compression, reliability, and power output—and the WSM Original Series kit gives you everything needed in one complete package. Whether...
    01080212
    SKU:
    01080212
    Availability:
    Ships Same Business Day
    Weight:
    2.85 LBS
    BORE SIZE METRIC:
    77.50 MM
    PRODUCT NAME:
    REBUILD KIT
    BORE - OVERSIZE:
    +0,50 MM
    BORE - OVERSIZE METRIC:
    +0.50 MM
    MODEL:
    ORIGINAL SERIES
    PISTON MATERIAL:
    ALUMINUM
    RIDING STYLE:
    WATERCRAFT
    TYPE:
    TOP END
    UNITS:
    EACH
    Qty in Cart: 0
    Quantity:
    Price:
    $247.87
    Subtotal:
  • WSM Piston Kit - Kawasaki - Standard 010-810K

    WSM Piston Kit - Kawasaki - Standard 010-810K

    WSM

    $82.17
    Your piston kit is the foundation of reliable power output and engine longevity. OEM-equivalent construction combined with advanced thermal management means you're getting professional-grade...
    010810
    SKU:
    010810
    Availability:
    Ships Same Business Day
    Weight:
    0.81 LBS
    BORE - OVERSIZE:
    STANDARD
    BORE - OVERSIZE METRIC:
    STANDARD
    MODEL:
    ORIGINAL
    PRODUCT NAME:
    PISTON KIT
    UNITS:
    KIT
    RIDING STYLE:
    WATERCRAFT
    BORE SIZE METRIC:
    76.00 MM
    PISTON MATERIAL:
    ALUMINUM
    Qty in Cart: 0
    Quantity:
    Price:
    $82.17
    Subtotal:
  • WSM Piston Kit - Kawasaki - +.25 mm 010-810-04K

    WSM Piston Kit - Kawasaki - +.25 mm 010-810-04K

    WSM

    $86.28
    When you're pushing your Kawasaki to the limit, stock pistons become your performance ceiling. The WSM Piston Kit delivers OEM-matching quality with critical upgrades—MOS2-coated skirts that actively...
    01081004
    SKU:
    01081004
    Availability:
    Ships Same Business Day
    Weight:
    0.81 LBS
    BORE - OVERSIZE:
    +0,25 MM
    BORE - OVERSIZE METRIC:
    +0.25 MM
    BORE SIZE METRIC:
    76.00 MM
    MODEL:
    ORIGINAL
    PRODUCT NAME:
    PISTON KIT
    PISTON MATERIAL:
    ALUMINUM
    RIDING STYLE:
    WATERCRAFT
    UNITS:
    KIT
    $86.28
    Qty in Cart: 0
    Quantity:
    Price:
    $86.28
    Subtotal:
  • WSM Piston Kit - Kawasaki 650 - +.5 mm 010-810-05K

    WSM Piston Kit - Kawasaki 650 - +.5 mm 010-810-05K

    WSM

    $86.28
    If you're rebuilding or upgrading your Kawasaki 650, piston quality directly impacts combustion efficiency, heat management, and engine longevity. The WSM Piston Kit delivers OEM-equivalent...
    01081005
    SKU:
    01081005
    Availability:
    Ships Same Business Day
    Weight:
    0.81 LBS
    BORE - OVERSIZE METRIC:
    +0.50 MM
    RIDING STYLE:
    WATERCRAFT
    MODEL:
    ORIGINAL
    PISTON MATERIAL:
    ALUMINUM
    BORE SIZE METRIC:
    76.00 MM
    PRODUCT NAME:
    PISTON KIT
    BORE - OVERSIZE:
    +0,50 MM
    UNITS:
    KIT
    $86.28
    Qty in Cart: 0
    Quantity:
    Price:
    $86.28
    Subtotal:
  • WSM Top-End Rebuild Kit - Original Series - Standard 010-810-10

    WSM Top-End Rebuild Kit - Original Series - Standard 010-810-10

    WSM

    $252.25
    A top-end rebuild demands precision components that restore your engine to factory specifications or better. The WSM Top-End Rebuild Kit eliminates the guesswork of sourcing individual gaskets,...
    01081010
    SKU:
    01081010
    Availability:
    Ships Same Business Day
    Weight:
    2.55 LBS
    MODEL:
    ORIGINAL SERIES
    PISTON MATERIAL:
    ALUMINUM
    RIDING STYLE:
    WATERCRAFT
    BORE - OVERSIZE:
    STANDARD
    BORE - OVERSIZE METRIC:
    STANDARD
    BORE SIZE METRIC:
    76.00 MM
    PRODUCT NAME:
    REBUILD KIT
    TYPE:
    TOP END
    UNITS:
    EACH
    Qty in Cart: 0
    Quantity:
    Price:
    $252.25
    Subtotal:
  • WSM Top-End Rebuild Kit - Original Series - 1 mm 010-810-14

    WSM Top-End Rebuild Kit - Original Series - 1 mm 010-810-14

    WSM

    $252.25
    A complete top-end rebuild requires precision-matched components that work as an integrated system—not mismatched parts cobbled together. The WSM Original Series kit eliminates guesswork by pairing...
    01081014
    SKU:
    01081014
    Availability:
    Ships Same Business Day
    Weight:
    2.65 LBS
    TYPE:
    TOP END
    UNITS:
    EACH
    BORE - OVERSIZE:
    +1,00 MM
    BORE SIZE METRIC:
    77.00 MM
    BORE - OVERSIZE METRIC:
    +1.00 MM
    PISTON MATERIAL:
    ALUMINUM
    MODEL:
    ORIGINAL SERIES
    PRODUCT NAME:
    REBUILD KIT
    RIDING STYLE:
    WATERCRAFT
    Qty in Cart: 0
    Quantity:
    Price:
    $252.25
    Subtotal:
  • WSM Piston Kit - Kawasaki 550 - +.5 mm 010-812-05K

    WSM Piston Kit - Kawasaki 550 - +.5 mm 010-812-05K

    WSM

    $81.73
    If you're building or rebuilding a Kawasaki 550 engine, piston quality directly impacts reliability, power output, and engine longevity. WSM pistons are engineered to OEM or better standards with...
    01081205
    SKU:
    01081205
    Availability:
    Ships Same Business Day
    Weight:
    0.70 LBS
    PRODUCT NAME:
    PISTON KIT
    BORE - OVERSIZE:
    +0,50 MM
    BORE - OVERSIZE METRIC:
    +0.50 MM
    BORE SIZE METRIC:
    75.00 MM
    PISTON MATERIAL:
    ALUMINUM
    RIDING STYLE:
    WATERCRAFT
    UNITS:
    KIT
    MODEL:
    ORIGINAL
    Qty in Cart: 0
    Quantity:
    Price:
    $81.73
    Subtotal:
  • WSM Top-End Rebuild Kit - Original Series - Standard 010-812-10

    WSM Top-End Rebuild Kit - Original Series - Standard 010-812-10

    WSM

    $205.60
    A top-end rebuild is essential when your engine shows signs of wear—loss of compression, increased blow-by, or declining power output. The WSM Top-End Rebuild Kit delivers OEM-quality components...
    01081210
    SKU:
    01081210
    Availability:
    Ships Same Business Day
    Weight:
    2.45 LBS
    PISTON MATERIAL:
    ALUMINUM
    RIDING STYLE:
    WATERCRAFT
    BORE - OVERSIZE METRIC:
    STANDARD
    BORE - OVERSIZE:
    STANDARD
    BORE SIZE METRIC:
    75.00 MM
    UNITS:
    EACH
    MODEL:
    ORIGINAL SERIES
    PRODUCT NAME:
    REBUILD KIT
    TYPE:
    TOP END
    $205.60
    Qty in Cart: 0
    Quantity:
    Price:
    $205.60
    Subtotal:
  • WSM Top-End Rebuild Kit - Original Series - Standard 010-816-10

    WSM Top-End Rebuild Kit - Original Series - Standard 010-816-10

    WSM

    $223.48
    A top-end rebuild is essential when your engine shows signs of wear—loss of compression, increased blow-by, or declining power output. The WSM Top-End Rebuild Kit delivers OEM-quality components...
    01081610
    SKU:
    01081610
    Availability:
    Ships Same Business Day
    Weight:
    2.88 LBS
    BORE - OVERSIZE:
    STANDARD
    BORE - OVERSIZE METRIC:
    STANDARD
    PRODUCT NAME:
    REBUILD KIT
    MODEL:
    ORIGINAL SERIES
    PISTON MATERIAL:
    ALUMINUM
    RIDING STYLE:
    WATERCRAFT
    TYPE:
    TOP END
    UNITS:
    EACH
    BORE SIZE METRIC:
    78.00 MM
    $223.48
    Qty in Cart: 0
    Quantity:
    Price:
    $223.48
    Subtotal:
  • Total: items /

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Dirt Bike Engine Parts

Keep your dirt bike running smoothly and prolong the life of its engine with essential general maintenance. But when parts start to break down, don't let it stop you from getting out on the trails! JJ Motorsports has all that you need for minor jobs like oil changes or major overhauls such as a complete rebuild - carrying top aftermarket brands . Get back in gear faster by shopping our full line of high-quality dirt bike engine parts here today at JJ Motorsports!

 

At JJ Motorsports, we want to make sure you don't miss out on the ride! If your motor has blown or radiator smashed, our gearheads can help get you back in the seat. We carry piston kits from top brands like Wiseco and Wrench Rabbit engine kits so that riders have access to a wide range of parts for their dirt bike engine rebuilds. Plus – with gaskets at-the-ready when it comes time for any leakages - no need to worry about maintenance issues either; simply stay up on oil & filter changes and let us take care of everything else. Got queries? Just give one of our knowledgeable staff members a call at 1-231‐767‐5055 where they'll be more than happy provide advice, instructions and tailored answers catered just for YOU!

Big Power, Nice Sound!

Picked up a Pro Circuit pipe and silencer for my YZ125 it’s a game changer. The power feels way better and the sound is awesome.

Tyler D. - 06/12

Perfect Fit

First time ordering here and dang y’all knocked it outta the park! The wheels fit my Ranger UTV perfect, and I’ll definitely be back for more 5 stars all day!

Sarah L. - 08/24

Fast Shipping!!

Ordered on a Monday, and it was on my doorstep by Wednesday! Super impressed with how fast the shipping was.

Jason P. - 09/13

Helps keep cool, works great!

Bought the dual pass Allstar radiator for my build, and it’s been solid. Keeps the engine running cool even on the hottest days no complaints here!

Jake M. - 05/21

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