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
  • KIBBLEWHITE Intake Valve Guide 80-80040

    KIBBLEWHITE Intake Valve Guide 80-80040

    KIBBLEWHITE

    $19.83
    All valve guides are made of Ampco-45, a high-performance compound with 80% copper content to provide great heat conductivity and 5% nickel content for wear resistance, Made in the U.S.A.
    KW8080040
    SKU:
    KW8080040
    Availability:
    Ships Same Business Day
    Weight:
    0.05 LBS
    MATERIAL:
    AMPCO-45
    APPLICATION:
    INTAKE
    RIDING STYLE:
    ATV
    SIZE IMPERIAL:
    STANDARD
    UNITS:
    EACH
    OUTSIDE DIAMETER IMPERIAL:
    0.4550'
    RIDING STYLE:
    UTV
    INSIDE DIAMETER IMPERIAL:
    0.2345'
    PRODUCT NAME:
    VALVE GUIDE
    $19.83
    Qty in Cart: 0
    Quantity:
    Price:
    $19.83
    Subtotal:
  • KIBBLEWHITE Exhaust Valve Guide 80-80050

    KIBBLEWHITE Exhaust Valve Guide 80-80050

    KIBBLEWHITE

    $19.83
    All valve guides are made of Ampco-45, a high-performance compound with 80% copper content to provide great heat conductivity and 5% nickel content for wear resistance, Made in the U.S.A.
    KW8080050
    SKU:
    KW8080050
    Availability:
    Ships Same Business Day
    Weight:
    0.06 LBS
    APPLICATION:
    EXHAUST
    MATERIAL:
    AMPCO-45
    RIDING STYLE:
    ATV
    SIZE IMPERIAL:
    STANDARD
    UNITS:
    EACH
    INSIDE DIAMETER IMPERIAL:
    0.2348'
    OUTSIDE DIAMETER IMPERIAL:
    0.4550'
    RIDING STYLE:
    UTV
    PRODUCT NAME:
    VALVE GUIDE
    $19.83
    Qty in Cart: 0
    Quantity:
    Price:
    $19.83
    Subtotal:
  • KIBBLEWHITE Intake Valve 30-31462

    KIBBLEWHITE Intake Valve 30-31462

    KIBBLEWHITE

    $37.55
    Black Diamond™ valves are CNC machined from one-piece forgings of EV8 Stainless Steel, Black Diamond™ proprietary multi-stage process reduces friction, and provides superior resistance to corrosion and wear, Made in the U.S.A.
    09261136
    SKU:
    09261136
    Availability:
    Ships Same Business Day
    Weight:
    0.07 LBS
    HEAD DIAMETER METRIC:
    30.50 MM
    LENGTH IMPERIAL:
    3.500'
    MATERIAL:
    STAINLESS STEEL
    MODEL:
    BLACK DIAMOND™
    PRODUCT NAME:
    VALVE
    STEM DIAMETER IMPERIAL:
    0.1960'
    UNITS:
    EACH
    TULIP ANGLE:
    20°
    APPLICATION:
    INTAKE
    RIDING STYLE:
    OFF-ROAD
    $37.55
    Qty in Cart: 0
    Quantity:
    Price:
    $37.55
    Subtotal:
  • KIBBLEWHITE Exhaust Valve 30-31466

    KIBBLEWHITE Exhaust Valve 30-31466

    KIBBLEWHITE

    $37.55
    Black Diamond™ valves are CNC machined from one-piece forgings of EV8 Stainless Steel, Black Diamond™ proprietary multi-stage process reduces friction, and provides superior resistance to corrosion and wear, Made in the U.S.A.
    09261138
    SKU:
    09261138
    Availability:
    Ships Same Business Day
    Weight:
    0.06 LBS
    HEAD DIAMETER METRIC:
    25.00 MM
    TULIP ANGLE:
    20°
    APPLICATION:
    EXHAUST
    MATERIAL:
    STAINLESS STEEL
    PRODUCT NAME:
    VALVE
    LENGTH IMPERIAL:
    3.310'
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    EACH
    MODEL:
    BLACK DIAMOND™
    STEM DIAMETER IMPERIAL:
    0.1760'
    $37.55
    Qty in Cart: 0
    Quantity:
    Price:
    $37.55
    Subtotal:
  • KIBBLEWHITE Center Intake Valve 80-8056H

    KIBBLEWHITE Center Intake Valve 80-8056H

    KIBBLEWHITE

    $54.10
    White Diamond™ valves are CNC machined from one-piece forgings of EV8 Stainless Steel or Inconel-751, Electroplated with a 360º anode, to produce an even coat of the highest grade hard chrome finish, Made in the U.S.A.
    KW808056H
    SKU:
    KW808056H
    Availability:
    Ships Same Business Day
    Weight:
    0.05 LBS
    APPLICATION:
    CENTER INTAKE
    LENGTH IMPERIAL:
    3.280'
    TULIP ANGLE:
    15°
    UNITS:
    EACH
    MATERIAL:
    STEEL
    MODEL:
    WHITE DIAMOND™
    RIDING STYLE:
    OFF-ROAD
    SIZE METRIC:
    STANDARD
    STEM DIAMETER IMPERIAL:
    0.1765'
    HEAD DIAMETER METRIC:
    27.00 MM
    PRODUCT NAME:
    VALVE
    $54.10
    Qty in Cart: 0
    Quantity:
    Price:
    $54.10
    Subtotal:
  • KIBBLEWHITE Exhaust Valve 80-8057H

    KIBBLEWHITE Exhaust Valve 80-8057H

    KIBBLEWHITE

    $54.10
    White Diamond™ valves are CNC machined from one-piece forgings of EV8 Stainless Steel or Inconel-751, Electroplated with a 360º anode, to produce an even coat of the highest grade hard chrome finish, Made in the U.S.A.
    KW808057H
    SKU:
    KW808057H
    Availability:
    Ships Same Business Day
    Weight:
    0.05 LBS
    APPLICATION:
    EXHAUST
    HEAD DIAMETER METRIC:
    28.00 MM
    PRODUCT NAME:
    VALVE
    STEM DIAMETER IMPERIAL:
    0.1955'
    UNITS:
    EACH
    MATERIAL:
    STEEL
    MODEL:
    WHITE DIAMOND™
    RIDING STYLE:
    OFF-ROAD
    SIZE METRIC:
    STANDARD
    TULIP ANGLE:
    25°
    LENGTH IMPERIAL:
    3.220'
    $54.10
    Qty in Cart: 0
    Quantity:
    Price:
    $54.10
    Subtotal:
  • KIBBLEWHITE Exhaust Valve 30-30075

    KIBBLEWHITE Exhaust Valve 30-30075

    KIBBLEWHITE

    $54.10
    Black Diamond™ valves are CNC machined from one-piece forgings of EV8 Stainless Steel, Black Diamond™ proprietary multi-stage process reduces friction, and provides superior resistance to corrosion and wear, Made in the U.S.A.
    KW3030075
    SKU:
    KW3030075
    Availability:
    Ships Same Business Day
    Weight:
    0.05 LBS
    MATERIAL:
    STEEL
    RIDING STYLE:
    OFF-ROAD
    HEAD DIAMETER METRIC:
    23.50 MM
    UNITS:
    EACH
    APPLICATION:
    EXHAUST
    PRODUCT NAME:
    VALVE
    LENGTH IMPERIAL:
    3.765'
    MODEL:
    BLACK DIAMOND™
    STEM DIAMETER IMPERIAL:
    0.1955'
    TULIP ANGLE:
    29°
    $54.10
    Qty in Cart: 0
    Quantity:
    Price:
    $54.10
    Subtotal:
  • KIBBLEWHITE Intake Valve 30-30081

    KIBBLEWHITE Intake Valve 30-30081

    KIBBLEWHITE

    $54.10
    Black Diamond™ valves are CNC machined from one-piece forgings of EV8 Stainless Steel, Black Diamond™ proprietary multi-stage process reduces friction, and provides superior resistance to corrosion and wear, Made in the U.S.A.
    KW3030081
    SKU:
    KW3030081
    Availability:
    Ships Same Business Day
    Weight:
    0.05 LBS
    APPLICATION:
    INTAKE
    MATERIAL:
    STEEL
    PRODUCT NAME:
    VALVE
    STEM DIAMETER IMPERIAL:
    0.2160'
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    EACH
    HEAD DIAMETER METRIC:
    28.50 MM
    LENGTH IMPERIAL:
    3.805'
    MODEL:
    BLACK DIAMOND™
    TULIP ANGLE:
    23°
    $54.10
    Qty in Cart: 0
    Quantity:
    Price:
    $54.10
    Subtotal:
  • KIBBLEWHITE Intake Valve - TRX450R - Standard 30-30950

    KIBBLEWHITE Intake Valve - TRX450R - Standard 30-30950

    KIBBLEWHITE

    $31.01
    Black Diamond™ valves are CNC machined from one-piece forgings of EV8 Stainless Steel, Black Diamond™ proprietary multi-stage process reduces friction, and provides superior resistance to corrosion and wear, Made in the U.S.A.
    09260416
    SKU:
    09260416
    Availability:
    Ships Same Business Day
    Weight:
    0.05 LBS
    STEM DIAMETER IMPERIAL:
    0.2158'
    HEAD DIAMETER METRIC:
    36.00 MM
    MODEL:
    BLACK DIAMOND™
    APPLICATION:
    INTAKE
    LENGTH IMPERIAL:
    3.315'
    MATERIAL:
    STAINLESS STEEL
    PRODUCT NAME:
    VALVE
    RIDING STYLE:
    ATV
    TULIP ANGLE:
    20°
    UNITS:
    EACH
    $31.01
    Qty in Cart: 0
    Quantity:
    Price:
    $31.01
    Subtotal:
  • KIBBLEWHITE Spring Kit 30-30085

    KIBBLEWHITE Spring Kit 30-30085

    KIBBLEWHITE

    $108.01
    Spring kits contain springs and titanium upper collars; lower collars included as required; spring kits are engineered for use with standard and oversized valves, Spring kits come complete for one motor, Keepers are not included, Made in the U.S.A.
    KW3030085
    SKU:
    KW3030085
    Availability:
    Ships Same Business Day
    Weight:
    0.44 LBS
    RIDING STYLE:
    OFF-ROAD
    SPRING LIFT IMPERIAL:
    0.430'
    UNITS:
    KIT
    APPLICATION:
    INTAKE
    MATERIAL:
    TITANIUM
    PRODUCT NAME:
    SPRING KIT
    SPRING OPEN PRESSURE:
    201 LB
    APPLICATION:
    EXHAUST
    TYPE:
    VALVE
    $108.01
    Qty in Cart: 0
    Quantity:
    Price:
    $108.01
    Subtotal:
  • KIBBLEWHITE Exhaust Valve - TRX450R - Standard 30-30953

    KIBBLEWHITE Exhaust Valve - TRX450R - Standard 30-30953

    KIBBLEWHITE

    $31.01
    Black Diamond™ valves are CNC machined from one-piece forgings of EV8 Stainless Steel, Black Diamond™ proprietary multi-stage process reduces friction, and provides superior resistance to corrosion and wear, Made in the U.S.A.
    09260418
    SKU:
    09260418
    Availability:
    Ships Same Business Day
    Weight:
    0.06 LBS
    STEM DIAMETER IMPERIAL:
    0.1957'
    APPLICATION:
    EXHAUST
    MATERIAL:
    STAINLESS STEEL
    MODEL:
    BLACK DIAMOND™
    PRODUCT NAME:
    VALVE
    TULIP ANGLE:
    20°
    HEAD DIAMETER METRIC:
    30.00 MM
    UNITS:
    EACH
    LENGTH IMPERIAL:
    3.310'
    RIDING STYLE:
    ATV
    $31.01
    Qty in Cart: 0
    Quantity:
    Price:
    $31.01
    Subtotal:
  • KIBBLEWHITE Exhaust Valve 30-30090

    KIBBLEWHITE Exhaust Valve 30-30090

    KIBBLEWHITE

    $54.10
    Black Diamond™ valves are CNC machined from one-piece forgings of EV8 Stainless Steel, Black Diamond™ proprietary multi-stage process reduces friction, and provides superior resistance to corrosion and wear, Made in the U.S.A.
    KW3030090
    SKU:
    KW3030090
    Availability:
    Ships Same Business Day
    Weight:
    0.06 LBS
    UNITS:
    EACH
    APPLICATION:
    EXHAUST
    HEAD DIAMETER METRIC:
    22.50 MM
    LENGTH IMPERIAL:
    3.650'
    PRODUCT NAME:
    VALVE
    MODEL:
    BLACK DIAMOND™
    STEM DIAMETER IMPERIAL:
    0.2150'
    TULIP ANGLE:
    29°
    MATERIAL:
    STEEL
    RIDING STYLE:
    ATV
    $54.10
    Qty in Cart: 0
    Quantity:
    Price:
    $54.10
    Subtotal:
  • KIBBLEWHITE Spring Kit 30-31050

    KIBBLEWHITE Spring Kit 30-31050

    KIBBLEWHITE

    $207.81
    Spring kits contain springs and titanium upper collars; lower collars included as required; spring kits are engineered for use with standard and oversized valves, Spring kits come complete for one motor, Keepers are not included, Made in the U.S.A.
    09260420
    SKU:
    09260420
    Availability:
    Ships Same Business Day
    Weight:
    0.61 LBS
    MATERIAL:
    TITANIUM
    SPRING LIFT IMPERIAL:
    0.440'
    UNITS:
    KIT
    RIDING STYLE:
    OFF-ROAD
    TYPE:
    VALVE
    APPLICATION:
    INTAKE
    SPRING OPEN PRESSURE:
    INTAKE 147 LB, EXHAUST 203 LB
    APPLICATION:
    EXHAUST
    PRODUCT NAME:
    SPRING KIT
    $207.81
    Qty in Cart: 0
    Quantity:
    Price:
    $207.81
    Subtotal:
  • KIBBLEWHITE Intake Valve - CRF450X - 2005-2007 - Standard 30-31062

    KIBBLEWHITE Intake Valve - CRF450X - 2005-2007 - Standard 30-31062

    KIBBLEWHITE

    $31.01
    Black Diamond™ valves are CNC machined from one-piece forgings of EV8 Stainless Steel, Black Diamond™ proprietary multi-stage process reduces friction, and provides superior resistance to corrosion and wear, Made in the U.S.A.
    09260421
    SKU:
    09260421
    Availability:
    Ships Same Business Day
    Weight:
    0.11 LBS
    RIDING STYLE:
    OFF-ROAD
    APPLICATION:
    INTAKE
    HEAD DIAMETER METRIC:
    35.00 MM
    LENGTH IMPERIAL:
    3.315'
    STEM DIAMETER IMPERIAL:
    0.2158'
    UNITS:
    EACH
    MATERIAL:
    STAINLESS STEEL
    PRODUCT NAME:
    VALVE
    TULIP ANGLE:
    20°
    MODEL:
    BLACK DIAMOND™
    $31.01
    Qty in Cart: 0
    Quantity:
    Price:
    $31.01
    Subtotal:
  • KIBBLEWHITE Intake Valve - CRF250R - 2008 - Standard 30-31162

    KIBBLEWHITE Intake Valve - CRF250R - 2008 - Standard 30-31162

    KIBBLEWHITE

    $37.55
    Black Diamond™ valves are CNC machined from one-piece forgings of EV8 Stainless Steel, Black Diamond™ proprietary multi-stage process reduces friction, and provides superior resistance to corrosion and wear, Made in the U.S.A.
    09260430
    SKU:
    09260430
    Availability:
    Ships Same Business Day
    Weight:
    0.06 LBS
    APPLICATION:
    INTAKE
    LENGTH IMPERIAL:
    3.280'
    UNITS:
    EACH
    HEAD DIAMETER METRIC:
    31.00 MM
    MATERIAL:
    STAINLESS STEEL
    PRODUCT NAME:
    VALVE
    RIDING STYLE:
    OFF-ROAD
    TULIP ANGLE:
    20°
    MODEL:
    BLACK DIAMOND™
    STEM DIAMETER IMPERIAL:
    0.1957'
    $37.55
    Qty in Cart: 0
    Quantity:
    Price:
    $37.55
    Subtotal:
  • KIBBLEWHITE Exhaust Valve - CRF250R - 2008 - Standard 30-31166

    KIBBLEWHITE Exhaust Valve - CRF250R - 2008 - Standard 30-31166

    KIBBLEWHITE

    $37.55
    Black Diamond™ valves are CNC machined from one-piece forgings of EV8 Stainless Steel, Black Diamond™ proprietary multi-stage process reduces friction, and provides superior resistance to corrosion and wear, Made in the U.S.A.
    09260434
    SKU:
    09260434
    Availability:
    Ships Same Business Day
    Weight:
    0.06 LBS
    STEM DIAMETER IMPERIAL:
    0.1760'
    APPLICATION:
    EXHAUST
    MATERIAL:
    STAINLESS STEEL
    MODEL:
    BLACK DIAMOND™
    PRODUCT NAME:
    VALVE
    TULIP ANGLE:
    20°
    LENGTH IMPERIAL:
    3.235'
    HEAD DIAMETER METRIC:
    26.00 MM
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    EACH
    $37.55
    Qty in Cart: 0
    Quantity:
    Price:
    $37.55
    Subtotal:
  • KIBBLEWHITE Valve Spring Kit 30-3041

    KIBBLEWHITE Valve Spring Kit 30-3041

    KIBBLEWHITE

    $136.54
    Black Diamond™ valves feature one-piece stainless steel construction with stellite tips and special impregnation to improve wear properties and reduce friction; White Diamond® valves feature one-piece construction and hard chrome stems, Spring sets...
    KW303041
    SKU:
    KW303041
    Availability:
    Ships Same Business Day
    Weight:
    0.50 LBS
    SPRING LIFT IMPERIAL:
    0.400'
    APPLICATION:
    INTAKE
    MATERIAL:
    CHROME-SILICON
    SPRING OPEN PRESSURE:
    192 LB
    SPRING SEAT PRESSURE:
    76 LB
    UNITS:
    KIT
    APPLICATION:
    EXHAUST
    PRODUCT NAME:
    SPRING KIT
    RIDING STYLE:
    ATV
    SPRING LIFT:
    0,400'
    TYPE:
    VALVE
    $136.54
    Qty in Cart: 0
    Quantity:
    Price:
    $136.54
    Subtotal:
  • KIBBLEWHITE Intake/Exhaust Valve Guide 30-3100

    KIBBLEWHITE Intake/Exhaust Valve Guide 30-3100

    KIBBLEWHITE

    $34.40
    All valve guides are made of Ampco-45, a high-performance compound with 80% copper content to provide great heat conductivity and 5% nickel content for wear resistance, Made in the U.S.A.
    KW303100
    SKU:
    KW303100
    Availability:
    Ships Same Business Day
    Weight:
    0.05 LBS
    APPLICATION:
    EXHAUST
    MATERIAL:
    AMPCO-45
    MATERIAL:
    NICKEL
    SIZE IMPERIAL:
    STANDARD
    UNITS:
    EACH
    APPLICATION:
    INTAKE
    OUTSIDE DIAMETER IMPERIAL:
    0.4355'
    PRODUCT NAME:
    VALVE GUIDE
    INSIDE DIAMETER IMPERIAL:
    0.2155'
    MATERIAL:
    BRONZE
    RIDING STYLE:
    OFF-ROAD
    $34.40
    Qty in Cart: 0
    Quantity:
    Price:
    $34.40
    Subtotal:
  • KIBBLEWHITE Valve Spring Kit 30-3111

    KIBBLEWHITE Valve Spring Kit 30-3111

    KIBBLEWHITE

    $99.26
    Black Diamond™ valves feature one-piece stainless steel construction with stellite tips and special impregnation to improve wear properties and reduce friction; White Diamond® valves feature one-piece construction and hard chrome stems, Spring sets...
    KW303111
    SKU:
    KW303111
    Availability:
    Ships Same Business Day
    Weight:
    0.44 LBS
    MATERIAL:
    TITANIUM
    SPRING LIFT:
    0,300'
    SPRING SEAT PRESSURE:
    70 LB
    UNITS:
    KIT
    APPLICATION:
    INTAKE
    MATERIAL:
    STEEL
    SPRING OPEN PRESSURE:
    157 LB
    APPLICATION:
    EXHAUST
    PRODUCT NAME:
    SPRING KIT
    RIDING STYLE:
    ATV
    SPRING LIFT IMPERIAL:
    0.300'
    TYPE:
    VALVE
    $99.26
    Qty in Cart: 0
    Quantity:
    Price:
    $99.26
    Subtotal:
  • KIBBLEWHITE Intake Kit 40-40350

    KIBBLEWHITE Intake Kit 40-40350

    KIBBLEWHITE

    $185.23
    Stainless steel conversion kit includes only what's needed to convert your head to the long-life stainless steel Black Diamond intake valves, Extends the life of the valvetrain and intake components by as much as 4x over the OEM titanium parts, Includes...
    09260452
    SKU:
    09260452
    Availability:
    Ships Same Business Day
    Weight:
    0.25 LBS
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    KIT
    MATERIAL:
    STAINLESS STEEL
    SPRING LIFT:
    0,445'
    SPRING OPEN PRESSURE:
    155 LB
    APPLICATION:
    INTAKE
    PRODUCT NAME:
    VALVE KIT
    SPRING SEAT PRESSURE:
    46 LB
    TYPE:
    CONVERSION
    SPRING LIFT IMPERIAL:
    0.445'
    $185.23
    Qty in Cart: 0
    Quantity:
    Price:
    $185.23
    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