Select Your Ride

1
2
3

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
  • BOYESEN Ignition Cover - Black - KX250 SC12B

    BOYESEN Ignition Cover - Black - KX250 SC12B

    BOYESEN

    $87.95
    Factory Ignition Cover SC12B Professional-grade design enhances the look of your engine. Seals effectively to protect against dirt and water intrusion. Durable construction outlasts standard stock covers. Manufactured from premium...
    SC12B
    SKU:
    SC12B
    Availability:
    Ships Same Business Day
    Weight:
    0.69 LBS
    COLOR/FINISH:
    POWDER-COATED
    UNITS:
    EACH
    COLOR/FINISH:
    BLACK
    PRODUCT NAME:
    COVER
    RIDING STYLE:
    OFF-ROAD
    TYPE:
    IGNITION
    MATERIAL:
    ALUMINUM
    MODEL:
    FACTORY RACING
    $87.95
    Qty in Cart: 0
    Quantity:
    Price:
    $87.95
    Subtotal:
  • BOYESEN Ignition Cover - Black - KX125 SC-11AB

    BOYESEN Ignition Cover - Black - KX125 SC-11AB

    BOYESEN

    $87.95
    Factory Ignition Cover SC11AB Professional appearance enhances your engine's aesthetic. Seals effectively to protect the engine from dirt and water. Durable construction outlasts standard stock covers. Crafted from premium-grade aluminum...
    SC11AB
    SKU:
    SC11AB
    Availability:
    Ships Same Business Day
    Weight:
    0.64 LBS
    MATERIAL:
    ALUMINUM
    COLOR/FINISH:
    BLACK
    PRODUCT NAME:
    COVER
    COLOR/FINISH:
    POWDER-COATED
    MODEL:
    FACTORY RACING
    RIDING STYLE:
    OFF-ROAD
    TYPE:
    IGNITION
    UNITS:
    EACH
    $87.95
    Qty in Cart: 0
    Quantity:
    Price:
    $87.95
    Subtotal:
  • BOYESEN Ignition Cover - Black - CR500 SC03B

    BOYESEN Ignition Cover - Black - CR500 SC03B

    BOYESEN

    $87.95
    Factory Ignition Cover SC03B Professional appearance that enhances your engine's look. Seals effectively to protect the engine from dirt and water. Durable design outlasts standard stock covers. Crafted from premium-grade aluminum for...
    SC03B
    SKU:
    SC03B
    Availability:
    Ships Same Business Day
    Weight:
    0.69 LBS
    UNITS:
    EACH
    COLOR/FINISH:
    POWDER-COATED
    MATERIAL:
    ALUMINUM
    MODEL:
    FACTORY RACING
    COLOR/FINISH:
    BLACK
    PRODUCT NAME:
    COVER
    RIDING STYLE:
    OFF-ROAD
    TYPE:
    IGNITION
    $87.95
    Qty in Cart: 0
    Quantity:
    Price:
    $87.95
    Subtotal:
  • BOYESEN Ignition Cover - Black - CR250 SC02B

    BOYESEN Ignition Cover - Black - CR250 SC02B

    BOYESEN

    $87.95
    Factory Ignition Cover SC02B Professional appearance enhances your engine's look. Seals effectively to protect against dirt and water intrusion. Durable design outlasts standard stock covers. Crafted from premium aluminum for strength...
    SC02B
    SKU:
    SC02B
    Availability:
    Ships Same Business Day
    Weight:
    0.69 LBS
    MATERIAL:
    ALUMINUM
    COLOR/FINISH:
    BLACK
    PRODUCT NAME:
    COVER
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    EACH
    COLOR/FINISH:
    POWDER-COATED
    MODEL:
    FACTORY RACING
    TYPE:
    IGNITION
    $87.95
    Qty in Cart: 0
    Quantity:
    Price:
    $87.95
    Subtotal:
  • BOYESEN Ignition Cover - Black - CR125 SC01AB

    BOYESEN Ignition Cover - Black - CR125 SC01AB

    BOYESEN

    $87.95
    Factory Ignition Cover SC01AB Professional appearance enhances your bike's aesthetic. Seals effectively to protect the engine from dirt and moisture. Durable design outlasts standard ignition covers. Crafted from premium aluminum for...
    SC01AB
    SKU:
    SC01AB
    Availability:
    Ships Same Business Day
    Weight:
    0.63 LBS
    COLOR/FINISH:
    POWDER-COATED
    MODEL:
    FACTORY RACING
    PRODUCT NAME:
    COVER
    COLOR/FINISH:
    BLACK
    RIDING STYLE:
    OFF-ROAD
    TYPE:
    IGNITION
    UNITS:
    EACH
    MATERIAL:
    ALUMINUM
    $87.95
    Qty in Cart: 0
    Quantity:
    Price:
    $87.95
    Subtotal:
  • BOYESEN Clutch Cover - Black - YZ250 CC32AB

    BOYESEN Clutch Cover - Black - YZ250 CC32AB

    BOYESEN

    $95.95
    Set your ride apart from the rest with the ultimate look in race performance, Lightweight factory clutch covers provide years of outstanding protection, Individually surfaced for a perfect, leak-free fit, Super-tough, powder-coated finish resists...
    CC32AB
    SKU:
    CC32AB
    Availability:
    Ships Same Business Day
    Weight:
    1.13 LBS
    COLOR/FINISH:
    BLACK
    COLOR/FINISH:
    POWDER-COATED
    MODEL:
    FACTORY RACING
    PRODUCT NAME:
    COVER
    UNITS:
    EACH
    TYPE:
    CLUTCH
    RIDING STYLE:
    OFF-ROAD
    $95.95
    Qty in Cart: 0
    Quantity:
    Price:
    $95.95
    Subtotal:
  • BOYESEN Clutch Cover - Black - RM250 CC22B

    BOYESEN Clutch Cover - Black - RM250 CC22B

    BOYESEN

    $95.95
    Set your ride apart from the rest with the ultimate look in race performance, Lightweight factory clutch covers provide years of outstanding protection, Individually surfaced for a perfect, leak-free fit, Super-tough, powder-coated finish resists...
    CC22B
    SKU:
    CC22B
    Availability:
    Ships Same Business Day
    Weight:
    1.13 LBS
    TYPE:
    CLUTCH
    COLOR/FINISH:
    BLACK
    PRODUCT NAME:
    COVER
    UNITS:
    EACH
    COLOR/FINISH:
    POWDER-COATED
    MODEL:
    FACTORY RACING
    RIDING STYLE:
    OFF-ROAD
    $95.95
    Qty in Cart: 0
    Quantity:
    Price:
    $95.95
    Subtotal:
  • BOYESEN Clutch Cover - Black - RM125 CC21AB

    BOYESEN Clutch Cover - Black - RM125 CC21AB

    BOYESEN

    $95.95
    Set your ride apart from the rest with the ultimate look in race performance, Lightweight factory clutch covers provide years of outstanding protection, Individually surfaced for a perfect, leak-free fit, Super-tough, powder-coated finish resists...
    CC21AB
    SKU:
    CC21AB
    Availability:
    Ships Same Business Day
    Weight:
    1.06 LBS
    COLOR/FINISH:
    POWDER-COATED
    MODEL:
    FACTORY RACING
    COLOR/FINISH:
    BLACK
    RIDING STYLE:
    OFF-ROAD
    TYPE:
    CLUTCH
    PRODUCT NAME:
    COVER
    UNITS:
    EACH
    $95.95
    Qty in Cart: 0
    Quantity:
    Price:
    $95.95
    Subtotal:
  • BOYESEN Clutch Cover - Black - KX250 CC12B

    BOYESEN Clutch Cover - Black - KX250 CC12B

    BOYESEN

    $95.95
    Set your ride apart from the rest with the ultimate look in race performance, Lightweight factory clutch covers provide years of outstanding protection, Individually surfaced for a perfect, leak-free fit, Super-tough, powder-coated finish resists...
    CC12B
    SKU:
    CC12B
    Availability:
    Ships Same Business Day
    Weight:
    1.13 LBS
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    EACH
    COLOR/FINISH:
    BLACK
    COLOR/FINISH:
    POWDER-COATED
    MODEL:
    FACTORY RACING
    TYPE:
    CLUTCH
    PRODUCT NAME:
    COVER
    $95.95
    Qty in Cart: 0
    Quantity:
    Price:
    $95.95
    Subtotal:
  • BOYESEN Clutch Cover - KX250 CC-12AB

    BOYESEN Clutch Cover - KX250 CC-12AB

    BOYESEN

    $95.95
    Set your ride apart from the rest with the ultimate look in race performance, Lightweight factory clutch covers provide years of outstanding protection, Individually surfaced for a perfect, leak-free fit, Super-tough, powder-coated finish resists...
    CC12AB
    SKU:
    CC12AB
    Availability:
    Ships Same Business Day
    Weight:
    1.00 LBS
    COLOR/FINISH:
    POWDER-COATED
    TYPE:
    CLUTCH
    COLOR/FINISH:
    BLACK
    PRODUCT NAME:
    COVER
    MODEL:
    FACTORY RACING
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    EACH
    $95.95
    Qty in Cart: 0
    Quantity:
    Price:
    $95.95
    Subtotal:
  • BOYESEN Clutch Cover - Black - KX125 CC-11AB

    BOYESEN Clutch Cover - Black - KX125 CC-11AB

    BOYESEN

    $95.95
    Set your ride apart from the rest with the ultimate look in race performance, Lightweight factory clutch covers provide years of outstanding protection, Individually surfaced for a perfect, leak-free fit, Super-tough, powder-coated finish resists...
    CC11AB
    SKU:
    CC11AB
    Availability:
    Ships Same Business Day
    Weight:
    0.75 LBS
    RIDING STYLE:
    OFF-ROAD
    MODEL:
    FACTORY RACING
    UNITS:
    EACH
    COLOR/FINISH:
    BLACK
    COLOR/FINISH:
    POWDER-COATED
    TYPE:
    CLUTCH
    PRODUCT NAME:
    COVER
    $95.95
    Qty in Cart: 0
    Quantity:
    Price:
    $95.95
    Subtotal:
  • BOYESEN Clutch Cover - Black - CR250 CC02B

    BOYESEN Clutch Cover - Black - CR250 CC02B

    BOYESEN

    $95.95
    Set your ride apart from the rest with the ultimate look in race performance, Lightweight factory clutch covers provide years of outstanding protection, Individually surfaced for a perfect, leak-free fit, Super-tough, powder-coated finish resists...
    CC02B
    SKU:
    CC02B
    Availability:
    Ships Same Business Day
    Weight:
    1.06 LBS
    UNITS:
    EACH
    RIDING STYLE:
    OFF-ROAD
    COLOR/FINISH:
    BLACK
    COLOR/FINISH:
    POWDER-COATED
    MODEL:
    FACTORY RACING
    TYPE:
    CLUTCH
    PRODUCT NAME:
    COVER
    $95.95
    Qty in Cart: 0
    Quantity:
    Price:
    $95.95
    Subtotal:
  • BOYESEN Clutch Cover - Black - CR250 CC-02AB

    BOYESEN Clutch Cover - Black - CR250 CC-02AB

    BOYESEN

    $95.95
    Set your ride apart from the rest with the ultimate look in race performance, Lightweight factory clutch covers provide years of outstanding protection, Individually surfaced for a perfect, leak-free fit, Super-tough, powder-coated finish resists...
    CC02AB
    SKU:
    CC02AB
    Availability:
    Ships Same Business Day
    Weight:
    0.85 LBS
    UNITS:
    EACH
    PRODUCT NAME:
    COVER
    COLOR/FINISH:
    BLACK
    COLOR/FINISH:
    POWDER-COATED
    MODEL:
    FACTORY RACING
    RIDING STYLE:
    OFF-ROAD
    TYPE:
    CLUTCH
    $95.95
    Qty in Cart: 0
    Quantity:
    Price:
    $95.95
    Subtotal:
  • BOYESEN Clutch Cover - Black - CR125 CC01B

    BOYESEN Clutch Cover - Black - CR125 CC01B

    BOYESEN

    $95.95
    Set your ride apart from the rest with the ultimate look in race performance, Lightweight factory clutch covers provide years of outstanding protection, Individually surfaced for a perfect, leak-free fit, Super-tough, powder-coated finish resists...
    CC01B
    SKU:
    CC01B
    Availability:
    Ships Same Business Day
    Weight:
    0.94 LBS
    MODEL:
    FACTORY RACING
    TYPE:
    CLUTCH
    COLOR/FINISH:
    BLACK
    PRODUCT NAME:
    COVER
    COLOR/FINISH:
    POWDER-COATED
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    EACH
    $95.95
    Qty in Cart: 0
    Quantity:
    Price:
    $95.95
    Subtotal:
  • BOYESEN Clutch Cover - Black - CR125 CC01AB

    BOYESEN Clutch Cover - Black - CR125 CC01AB

    BOYESEN

    $95.95
    Set your ride apart from the rest with the ultimate look in race performance, Lightweight factory clutch covers provide years of outstanding protection, Individually surfaced for a perfect, leak-free fit, Super-tough, powder-coated finish resists...
    CC01AB
    SKU:
    CC01AB
    Availability:
    Ships Same Business Day
    Weight:
    0.13 LBS
    PRODUCT NAME:
    COVER
    UNITS:
    EACH
    COLOR/FINISH:
    BLACK
    COLOR/FINISH:
    POWDER-COATED
    MODEL:
    FACTORY RACING
    RIDING STYLE:
    OFF-ROAD
    TYPE:
    CLUTCH
    $95.95
    Qty in Cart: 0
    Quantity:
    Price:
    $95.95
    Subtotal:
  • BOYESEN Impeller Pump CRF450 WPI-06

    BOYESEN Impeller Pump CRF450 WPI-06

    BOYESEN

    $79.95
    Designed to increase water flow and reduce hydraulic friction for a cooler, more constant temperature, Less horsepower loss during the late stages of a race, Extend engine life, Impellers are designed to minimize cavitation
    09500026
    SKU:
    09500026
    Availability:
    Ships Same Business Day
    Weight:
    0.15 LBS
    UNITS:
    EACH
    MATERIAL:
    ALUMINUM
    PRODUCT NAME:
    IMPELLER
    MODEL:
    SUPERCOOLER
    RIDING STYLE:
    OFF-ROAD
    TYPE:
    WATER PUMP
    $79.95
    Qty in Cart: 0
    Quantity:
    Price:
    $79.95
    Subtotal:
  • BOYESEN Impeller Water Pump Cover - Black - YZ125 WPK-31AB

    BOYESEN Impeller Water Pump Cover - Black - YZ125 WPK-31AB

    BOYESEN

    $219.95
    Increased coolant flow at all rpm ranges, Patented Nautilus-style impeller for hydrodynamic efficiency
    09401471
    SKU:
    09401471
    Availability:
    Ships Same Business Day
    Weight:
    0.40 LBS
    PRODUCT NAME:
    IMPELLER
    TYPE:
    WATER PUMP
    UNITS:
    KIT
    COLOR/FINISH:
    BLACK
    RIDING STYLE:
    OFF-ROAD
    STYLE:
    NAUTILUS
    BASE COLOR:
    BLACK
    MATERIAL:
    ALUMINUM
    MODEL:
    SUPERCOOLER
    PRODUCT NAME:
    COVER
    $219.95
    Qty in Cart: 0
    Quantity:
    Price:
    $219.95
    Subtotal:
  • BOYESEN Clutch Cover - Gold - Kawasaki CC-18AM

    BOYESEN Clutch Cover - Gold - Kawasaki CC-18AM

    BOYESEN

    $95.95
    Set your ride apart from the rest with the ultimate look in race performance, Lightweight factory clutch covers provide years of outstanding protection, Individually surfaced for a perfect, leak-free fit, Super-tough, powder-coated finish resists...
    09401466
    SKU:
    09401466
    Availability:
    Ships Same Business Day
    Weight:
    0.90 LBS
    COLOR/FINISH:
    MAGNESIUM
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    EACH
    TYPE:
    CLUTCH
    COLOR/FINISH:
    POWDER-COATED
    MODEL:
    FACTORY RACING
    PRODUCT NAME:
    COVER
    $95.95
    Qty in Cart: 0
    Quantity:
    Price:
    $95.95
    Subtotal:
  • BOYESEN Clutch Cover - Black - Kawasaki CC-18AB

    BOYESEN Clutch Cover - Black - Kawasaki CC-18AB

    BOYESEN

    $95.95
    Set your ride apart from the rest with the ultimate look in race performance, Lightweight factory clutch covers provide years of outstanding protection, Individually surfaced for a perfect, leak-free fit, Super-tough, powder-coated finish resists...
    09401465
    SKU:
    09401465
    Availability:
    Ships Same Business Day
    Weight:
    0.85 LBS
    RIDING STYLE:
    OFF-ROAD
    COLOR/FINISH:
    POWDER-COATED
    MODEL:
    FACTORY RACING
    PRODUCT NAME:
    COVER
    TYPE:
    CLUTCH
    COLOR/FINISH:
    BLACK
    UNITS:
    EACH
    $95.95
    Qty in Cart: 0
    Quantity:
    Price:
    $95.95
    Subtotal:
  • BOYESEN Clutch Cover - Gold - KTM/Husqvarna CC-45AM

    BOYESEN Clutch Cover - Gold - KTM/Husqvarna CC-45AM

    BOYESEN

    $95.95
    Set your ride apart from the rest with the ultimate look in race performance, Lightweight factory clutch covers provide years of outstanding protection, Individually surfaced for a perfect, leak-free fit, Super-tough, powder-coated finish resists...
    09401462
    SKU:
    09401462
    Availability:
    Ships Same Business Day
    Weight:
    0.80 LBS
    UNITS:
    EACH
    COLOR/FINISH:
    MAGNESIUM
    COLOR/FINISH:
    POWDER-COATED
    MODEL:
    FACTORY RACING
    PRODUCT NAME:
    COVER
    RIDING STYLE:
    STREET
    RIDING STYLE:
    OFF-ROAD
    TYPE:
    CLUTCH
    $95.95
    Qty in Cart: 0
    Quantity:
    Price:
    $95.95
    Subtotal:
  • Total: items /

Adding your products to cart

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

SECURE & SAFE PAYMENT

EASY RETURNS

FAST DELIVERY

AUTHORIZED DEALER