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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 Valve and Spring Kit M30-32785

    MOOSE RACING Valve and Spring Kit M30-32785

    MOOSE RACING

    $217.95
    If you're running high-mileage on your current valve train, stainless steel upgrades deliver measurable gains in durability and flow—extending component life by up to 4x compared to OEM titanium parts. The MOOSE RACING M30-32785 kit replaces your intake...
    09263195
    SKU:
    09263195
    Availability:
    Ships Same Business Day
    Weight:
    0.45 LBS
    APPLICATION:
    EXHAUST
    MATERIAL:
    STAINLESS STEEL
    PRODUCT NAME:
    VALVE
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    KIT
    Qty in Cart: 0
    Quantity:
    Price:
    $217.95
    Subtotal:
  • MOOSE RACING Intake Valve Kit M96-96540

    MOOSE RACING Intake Valve Kit M96-96540

    MOOSE RACING

    $217.95
    If you're running high-mileage or competitive applications, OEM titanium intake valves will eventually limit your engine's reliability and flow potential. The MOOSE RACING Black Diamond stainless steel conversion kit replaces worn valve train components...
    09263196
    SKU:
    09263196
    Availability:
    Ships Same Business Day
    Weight:
    0.60 LBS
    MATERIAL:
    STAINLESS STEEL
    PRODUCT NAME:
    VALVE
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    KIT
    APPLICATION:
    INTAKE
    Qty in Cart: 0
    Quantity:
    Price:
    $217.95
    Subtotal:
  • MOOSE RACING Intake Valve Kit M40-41450

    MOOSE RACING Intake Valve Kit M40-41450

    MOOSE RACING

    $217.95
    OEM intake valves wear out, and replacement cycles eat into your bottom line. The MOOSE RACING Intake Valve Kit M40-41450 extends valve train life by up to 4x compared to stock titanium components while simultaneously improving flow characteristics and...
    09263198
    SKU:
    09263198
    Availability:
    Ships Same Business Day
    Weight:
    0.50 LBS
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    KIT
    MATERIAL:
    STAINLESS STEEL
    PRODUCT NAME:
    VALVE
    APPLICATION:
    INTAKE
    $217.95
    Qty in Cart: 0
    Quantity:
    Price:
    $217.95
    Subtotal:
  • MOOSE RACING Valve and Spring Kit M40-41455

    MOOSE RACING Valve and Spring Kit M40-41455

    MOOSE RACING

    $196.95
    If you're running high-mileage track sessions or pushing your engine to the limit, OEM titanium intake valves will eventually cost you reliability and performance. The MOOSE RACING Valve and Spring Kit replaces those wear-prone components with stainless...
    09263199
    SKU:
    09263199
    Availability:
    Ships Same Business Day
    Weight:
    0.35 LBS
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    KIT
    APPLICATION:
    EXHAUST
    MATERIAL:
    STAINLESS STEEL
    PRODUCT NAME:
    VALVE
    $196.95
    Qty in Cart: 0
    Quantity:
    Price:
    $196.95
    Subtotal:
  • MOOSE RACING Valve Seal Kit M40-41460

    MOOSE RACING Valve Seal Kit M40-41460

    MOOSE RACING

    $15.95
    Valve seal degradation is a common culprit behind oil consumption, blow-by, and performance loss—especially under high-heat or high-boost conditions. The MOOSE RACING Valve Seal Kit M40-41460 replaces worn OEM seals with precision-engineered components...
    09263202
    SKU:
    09263202
    Availability:
    Ships Same Business Day
    Weight:
    0.05 LBS
    PRODUCT NAME:
    SEAL KIT
    TYPE:
    VALVE STEM
    UNITS:
    KIT
    APPLICATION:
    EXHAUST
    BASE COLOR:
    RED
    MATERIAL:
    VITON
    RIDING STYLE:
    OFF-ROAD
    APPLICATION:
    INTAKE
    COLOR/FINISH:
    RED
    $15.95
    Qty in Cart: 0
    Quantity:
    Price:
    $15.95
    Subtotal:
  • MOOSE RACING Intake Valve Kit M30-33680

    MOOSE RACING Intake Valve Kit M30-33680

    MOOSE RACING

    $217.95
    If you're running high-revving applications or extended racing seasons, OEM titanium intake valves will eventually fail you—often at the worst possible moment. The MOOSE RACING Stainless Steel Intake Valve Kit M30-33680 replaces that weak link with Black...
    09263303
    SKU:
    09263303
    Availability:
    Ships Same Business Day
    Weight:
    0.41 LBS
    APPLICATION:
    INTAKE
    PRODUCT NAME:
    VALVE KIT
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    KIT
    $217.95
    Qty in Cart: 0
    Quantity:
    Price:
    $217.95
    Subtotal:
  • MOOSE RACING Magnetic Drain Plug DP107-1

    MOOSE RACING Magnetic Drain Plug DP107-1

    MOOSE RACING

    $23.95
    Metal debris circulating through your engine oil accelerates wear on critical components—bearings, cylinder walls, and valve trains. The MOOSE RACING Magnetic Drain Plug DP107-1 captures ferrous particles before they cause damage, extending engine...
    09200045
    SKU:
    09200045
    Availability:
    Ships Same Business Day
    Weight:
    0.06 LBS
    RIDING STYLE:
    OFF-ROAD
    TYPE:
    DRAIN
    COLOR/FINISH:
    RED
    PRODUCT NAME:
    PLUG
    RIDING STYLE:
    STREET
    UNITS:
    EACH
    DIAMETER - THREAD SIZE METRIC:
    M12 X 1.50 X 22 MM
    FEATURES:
    MAGNETIC
    MATERIAL:
    7075 ALUMINUM
    Qty in Cart: 0
    Quantity:
    Price:
    $23.95
    Subtotal:
  • MOOSE RACING Magnetic Drain Plug DP108

    MOOSE RACING Magnetic Drain Plug DP108

    MOOSE RACING

    $23.95
    Engine wear accelerates when ferrous particles circulate through your oil system—particles that standard drain plugs simply miss. The MOOSE RACING Magnetic Drain Plug DP108 captures these metal filings before they cause scoring, bearing damage, and...
    09200046
    SKU:
    09200046
    Availability:
    Ships Same Business Day
    Weight:
    0.06 LBS
    FEATURES:
    MAGNETIC
    MATERIAL:
    7075 ALUMINUM
    DIAMETER - THREAD SIZE METRIC:
    M12 X 1.50 X 20 MM
    RIDING STYLE:
    OFF-ROAD
    COLOR/FINISH:
    ORANGE
    PRODUCT NAME:
    PLUG
    UNITS:
    EACH
    TYPE:
    DRAIN
    $23.95
    Qty in Cart: 0
    Quantity:
    Price:
    $23.95
    Subtotal:
  • MOOSE RACING Magnetic Drain Plug DP115

    MOOSE RACING Magnetic Drain Plug DP115

    MOOSE RACING

    $23.95
    Metal particles inevitably accumulate in your engine oil—especially under high-performance driving conditions. The MOOSE RACING Magnetic Drain Plug DP115 captures ferrous debris before it can cause wear on critical engine components, extending bearing...
    09200047
    SKU:
    09200047
    Availability:
    Ships Same Business Day
    Weight:
    0.06 LBS
    DIAMETER - THREAD SIZE METRIC:
    M16 X 1.50 X 12 MM
    MATERIAL:
    7075 ALUMINUM
    PRODUCT NAME:
    PLUG
    UNITS:
    EACH
    COLOR/FINISH:
    SILVER
    FEATURES:
    NON-MAGNETIC
    RIDING STYLE:
    OFF-ROAD
    TYPE:
    DRAIN
    $23.95
    Qty in Cart: 0
    Quantity:
    Price:
    $23.95
    Subtotal:
  • MOOSE RACING Magnetic Drain Plug DP120

    MOOSE RACING Magnetic Drain Plug DP120

    MOOSE RACING

    $23.95
    Metal particles inevitably circulate through your engine oil during normal operation—accelerating wear on critical components. The MOOSE RACING Magnetic Drain Plug DP120 captures ferrous debris before it causes damage, effectively extending engine...
    09200049
    SKU:
    09200049
    Availability:
    Ships Same Business Day
    Weight:
    0.06 LBS
    PRODUCT NAME:
    PLUG
    UNITS:
    EACH
    MATERIAL:
    7075 ALUMINUM
    FEATURES:
    MAGNETIC
    RIDING STYLE:
    OFF-ROAD
    TYPE:
    DRAIN
    COLOR/FINISH:
    RED
    DIAMETER - THREAD SIZE METRIC:
    M10 X 1.50 X 22 MM
    RIDING STYLE:
    ADVENTURE TOURING / DUAL-SPORT
    $23.95
    Qty in Cart: 0
    Quantity:
    Price:
    $23.95
    Subtotal:
  • MOOSE RACING Valve Shim - 10.0 x 2.95 - 5 pack MSE5PK1000295

    MOOSE RACING Valve Shim - 10.0 x 2.95 - 5 pack MSE5PK1000295

    MOOSE RACING

    $10.95
    Proper valve clearance is critical to engine performance and longevity—even slight deviations can cause compression loss, valve float, or premature wear. These MOOSE RACING valve shims give you precision control over your valve train geometry without the...
    09261852
    SKU:
    09261852
    Availability:
    Ships Same Business Day
    Weight:
    0.02 LBS
    MATERIAL:
    ROLLED
    VALVE SHIM THICKNESS METRIC:
    2.95 MM
    OUTSIDE DIAMETER METRIC:
    10.00 MM
    RIDING STYLE:
    UTV
    RIDING STYLE:
    WATERCRAFT
    TYPE:
    VALVE
    PRODUCT NAME:
    SHIM
    RIDING STYLE:
    ADVENTURE TOURING / DUAL-SPORT
    RIDING STYLE:
    SNOW
    RIDING STYLE:
    STREET
    UNITS:
    5 PACK
    MATERIAL:
    STEEL
    RIDING STYLE:
    ATV
    RIDING STYLE:
    OFF-ROAD
    $10.95
    Qty in Cart: 0
    Quantity:
    Price:
    $10.95
    Subtotal:
  • MOOSE RACING Valve Shim - 10.0 x 3.15 - 5 pack MSE5PK1000315

    MOOSE RACING Valve Shim - 10.0 x 3.15 - 5 pack MSE5PK1000315

    MOOSE RACING

    $10.95
    Valve shim maintenance demands precision—improper sizing compromises valve clearance and engine performance. These MOOSE RACING shims eliminate guesswork with laser-etched identification, ensuring you select the correct size every time during valve train...
    09261856
    SKU:
    09261856
    Availability:
    Ships Same Business Day
    Weight:
    0.01 LBS
    OUTSIDE DIAMETER METRIC:
    10.00 MM
    RIDING STYLE:
    ADVENTURE TOURING / DUAL-SPORT
    RIDING STYLE:
    ATV
    RIDING STYLE:
    STREET
    VALVE SHIM THICKNESS METRIC:
    3.15 MM
    MATERIAL:
    STEEL
    RIDING STYLE:
    OFF-ROAD
    RIDING STYLE:
    UTV
    MATERIAL:
    ROLLED
    PRODUCT NAME:
    SHIM
    RIDING STYLE:
    SNOW
    RIDING STYLE:
    WATERCRAFT
    TYPE:
    VALVE
    UNITS:
    5 PACK
    $10.95
    Qty in Cart: 0
    Quantity:
    Price:
    $10.95
    Subtotal:
  • MOOSE RACING Valve Shim - 7.48 x 1.25 - 5 pack MSE5PK748125

    MOOSE RACING Valve Shim - 7.48 x 1.25 - 5 pack MSE5PK748125

    MOOSE RACING

    $9.95
    Proper valve clearance is critical for engine performance, reliability, and longevity—and maintaining it requires the right shims on hand. The MOOSE RACING Valve Shim 5-pack gives you precision-engineered replacements ready for any valve train...
    09261859
    SKU:
    09261859
    Availability:
    Ships Same Business Day
    Weight:
    0.05 LBS
    RIDING STYLE:
    ATV
    TYPE:
    VALVE
    MATERIAL:
    ROLLED
    MATERIAL:
    STEEL
    RIDING STYLE:
    OFF-ROAD
    RIDING STYLE:
    SNOW
    VALVE SHIM THICKNESS METRIC:
    1.25 MM
    OUTSIDE DIAMETER METRIC:
    7.48 MM
    PRODUCT NAME:
    SHIM
    RIDING STYLE:
    ADVENTURE TOURING / DUAL-SPORT
    RIDING STYLE:
    STREET
    RIDING STYLE:
    UTV
    RIDING STYLE:
    WATERCRAFT
    UNITS:
    5 PACK
    $9.95
    Qty in Cart: 0
    Quantity:
    Price:
    $9.95
    Subtotal:
  • MOOSE RACING Valve Shim - 7.48 x 2.85 - 5 pack MSE5PK748285

    MOOSE RACING Valve Shim - 7.48 x 2.85 - 5 pack MSE5PK748285

    MOOSE RACING

    $9.95
    Valve train maintenance demands precision, and these MOOSE RACING shims deliver it. Forged from 4140 cold rolled steel—not sintered material—they maintain tight tolerances through repeated thermal cycles and adjustment procedures. The laser-etched sizing...
    09261891
    SKU:
    09261891
    Availability:
    Ships Same Business Day
    Weight:
    0.05 LBS
    OUTSIDE DIAMETER METRIC:
    7.48 MM
    PRODUCT NAME:
    SHIM
    RIDING STYLE:
    ADVENTURE TOURING / DUAL-SPORT
    RIDING STYLE:
    SNOW
    RIDING STYLE:
    STREET
    UNITS:
    5 PACK
    MATERIAL:
    ROLLED
    RIDING STYLE:
    UTV
    RIDING STYLE:
    WATERCRAFT
    TYPE:
    VALVE
    MATERIAL:
    STEEL
    RIDING STYLE:
    ATV
    RIDING STYLE:
    OFF-ROAD
    VALVE SHIM THICKNESS METRIC:
    2.85 MM
    Qty in Cart: 0
    Quantity:
    Price:
    $9.95
    Subtotal:
  • MOOSE RACING Valve Shim - 7.48 x 2.90 - 5 pack MSE5PK748290

    MOOSE RACING Valve Shim - 7.48 x 2.90 - 5 pack MSE5PK748290

    MOOSE RACING

    $9.95
    Valve shim maintenance demands precision components you can trust, and this 5-pack delivers exactly that. Forged from 4140 cold-rolled steel—not sintered—these shims resist deformation under valve spring pressure while maintaining accurate clearance...
    09261892
    SKU:
    09261892
    Availability:
    Ships Same Business Day
    Weight:
    0.05 LBS
    OUTSIDE DIAMETER METRIC:
    7.48 MM
    PRODUCT NAME:
    SHIM
    RIDING STYLE:
    ADVENTURE TOURING / DUAL-SPORT
    RIDING STYLE:
    SNOW
    RIDING STYLE:
    STREET
    UNITS:
    5 PACK
    VALVE SHIM THICKNESS METRIC:
    2.90 MM
    MATERIAL:
    ROLLED
    MATERIAL:
    STEEL
    RIDING STYLE:
    ATV
    RIDING STYLE:
    OFF-ROAD
    RIDING STYLE:
    UTV
    RIDING STYLE:
    WATERCRAFT
    TYPE:
    VALVE
    Qty in Cart: 0
    Quantity:
    Price:
    $9.95
    Subtotal:
  • MOOSE RACING Valve Shim - 7.48 x 3.00 - 5 pack MSE5PK748300

    MOOSE RACING Valve Shim - 7.48 x 3.00 - 5 pack MSE5PK748300

    MOOSE RACING

    $9.95
    Proper valve clearance is critical to engine performance and longevity—too tight and you'll lose power, too loose and you risk valve float and catastrophic damage. MOOSE RACING valve shims give you precise adjustment capability without guesswork, and...
    09261894
    SKU:
    09261894
    Availability:
    Ships Same Business Day
    Weight:
    0.05 LBS
    VALVE SHIM THICKNESS METRIC:
    3.00 MM
    MATERIAL:
    ROLLED
    MATERIAL:
    STEEL
    RIDING STYLE:
    OFF-ROAD
    OUTSIDE DIAMETER METRIC:
    7.48 MM
    RIDING STYLE:
    ADVENTURE TOURING / DUAL-SPORT
    RIDING STYLE:
    ATV
    RIDING STYLE:
    STREET
    PRODUCT NAME:
    SHIM
    RIDING STYLE:
    SNOW
    RIDING STYLE:
    UTV
    RIDING STYLE:
    WATERCRAFT
    TYPE:
    VALVE
    UNITS:
    5 PACK
    $9.95
    Qty in Cart: 0
    Quantity:
    Price:
    $9.95
    Subtotal:
  • MOOSE RACING Valve Shim - 7.48 x 3.05 - 5 pack MSE5PK748305

    MOOSE RACING Valve Shim - 7.48 x 3.05 - 5 pack MSE5PK748305

    MOOSE RACING

    $9.95
    Maintaining precise valve clearances is non-negotiable for engine longevity and consistent performance across heat cycles. These MOOSE RACING valve shims eliminate guesswork during valve train service by providing accurate, individually identifiable...
    09261895
    SKU:
    09261895
    Availability:
    Ships Same Business Day
    Weight:
    0.01 LBS
    RIDING STYLE:
    ATV
    TYPE:
    VALVE
    MATERIAL:
    STEEL
    RIDING STYLE:
    OFF-ROAD
    RIDING STYLE:
    UTV
    RIDING STYLE:
    WATERCRAFT
    VALVE SHIM THICKNESS METRIC:
    3.05 MM
    MATERIAL:
    ROLLED
    PRODUCT NAME:
    SHIM
    RIDING STYLE:
    SNOW
    UNITS:
    5 PACK
    OUTSIDE DIAMETER METRIC:
    7.48 MM
    RIDING STYLE:
    ADVENTURE TOURING / DUAL-SPORT
    RIDING STYLE:
    STREET
    Qty in Cart: 0
    Quantity:
    Price:
    $9.95
    Subtotal:
  • MOOSE RACING Valve Shim - 9.48 x 2.85 - 5 pack MSE5PK948285

    MOOSE RACING Valve Shim - 9.48 x 2.85 - 5 pack MSE5PK948285

    MOOSE RACING

    $9.95
    Proper valve clearance is critical to engine performance and longevity—and maintaining accurate shim specs means the difference between a finely-tuned engine and costly valve train damage. MOOSE RACING valve shims give you precision-engineered components...
    09261961
    SKU:
    09261961
    Availability:
    Ships Same Business Day
    Weight:
    0.05 LBS
    RIDING STYLE:
    ATV
    TYPE:
    VALVE
    RIDING STYLE:
    OFF-ROAD
    RIDING STYLE:
    UTV
    RIDING STYLE:
    WATERCRAFT
    VALVE SHIM THICKNESS METRIC:
    2.85 MM
    RIDING STYLE:
    ADVENTURE TOURING / DUAL-SPORT
    RIDING STYLE:
    STREET
    MATERIAL:
    ROLLED
    MATERIAL:
    STEEL
    OUTSIDE DIAMETER METRIC:
    9.48 MM
    PRODUCT NAME:
    SHIM
    RIDING STYLE:
    SNOW
    UNITS:
    5 PACK
    $9.95
    Qty in Cart: 0
    Quantity:
    Price:
    $9.95
    Subtotal:
  • MOOSE RACING Valve Shim - 9.48 x 2.95 - 5 pack MSE5PK948295

    MOOSE RACING Valve Shim - 9.48 x 2.95 - 5 pack MSE5PK948295

    MOOSE RACING

    $9.95
    Valve train maintenance requires precision—and guesswork doesn't belong in your engine bay. These MOOSE RACING valve shims give you the exact sizing and durability needed to dial in your valve clearances without the frustration of hunting down individual...
    09261963
    SKU:
    09261963
    Availability:
    Ships Same Business Day
    Weight:
    0.02 LBS
    OUTSIDE DIAMETER METRIC:
    9.48 MM
    MATERIAL:
    STEEL
    RIDING STYLE:
    OFF-ROAD
    RIDING STYLE:
    UTV
    VALVE SHIM THICKNESS METRIC:
    2.95 MM
    RIDING STYLE:
    ADVENTURE TOURING / DUAL-SPORT
    RIDING STYLE:
    ATV
    RIDING STYLE:
    STREET
    MATERIAL:
    ROLLED
    PRODUCT NAME:
    SHIM
    RIDING STYLE:
    SNOW
    RIDING STYLE:
    WATERCRAFT
    TYPE:
    VALVE
    UNITS:
    5 PACK
    $9.95
    Qty in Cart: 0
    Quantity:
    Price:
    $9.95
    Subtotal:
  • MOOSE RACING Gasket Material 403-5013

    MOOSE RACING Gasket Material 403-5013

    MOOSE RACING

    $34.29
    A quality gasket material is fundamental to maintaining engine integrity and preventing costly fluid leaks that compromise performance and reliability. MOOSE RACING's gasket material delivers consistent sealing performance across critical engine...
    09346977
    SKU:
    09346977
    Availability:
    Ships Same Business Day
    Weight:
    0.60 LBS
    UNITS:
    EACH
    RIDING STYLE:
    OFF-ROAD
    PRODUCT NAME:
    GASKET MATERIAL
    $34.29
    Qty in Cart: 0
    Quantity:
    Price:
    $34.29
    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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