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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KIBBLEWHITE Exhaust Valve 80-81316
KIBBLEWHITE
$37.55Black 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.09263030- SKU:
- 09263030
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- MATERIAL:
- STAINLESS STEEL
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- MODEL:
- BLACK DIAMOND™
- STEM DIAMETER IMPERIAL:
- 0.1760'
- TULIP ANGLE:
- 25°
- HEAD DIAMETER METRIC:
- 26.00 MM
- LENGTH IMPERIAL:
- 3.470'
- APPLICATION:
- EXHAUST
$37.55Qty in Cart: 0Quantity:Price:$37.55Subtotal: -
KIBBLEWHITE Intake Valve Kit 40-41450
KIBBLEWHITE
$185.23Stainless 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...09263154- SKU:
- 09263154
- Availability:
- Ships Same Business Day
- Weight:
- 0.51 LBS
- SPRING LIFT:
- 0,415'
- TYPE:
- CONVERSION
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- SPRING OPEN PRESSURE:
- 181 LB
- SPRING SEAT PRESSURE:
- 65 LB
- UNITS:
- KIT
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- SPRING LIFT IMPERIAL:
- 0.415'
$185.23 -
KIBBLEWHITE Valve Guide 96-96521
KIBBLEWHITE
$24.89All 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.09263157- SKU:
- 09263157
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
- APPLICATION:
- INTAKE
- RIDING STYLE:
- OFF-ROAD
- SIZE IMPERIAL:
- OVERSIZE (+0.001')
- UNITS:
- EACH
- INSIDE DIAMETER IMPERIAL:
- 0.2353'
- MATERIAL:
- C630 BRONZE
- OUTSIDE DIAMETER IMPERIAL:
- 0.4362'
- PRODUCT NAME:
- VALVE GUIDE
$24.89 -
KIBBLEWHITE Valve Conversion Kit 80-82350
KIBBLEWHITE
$172.15Stainless 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...09263177- SKU:
- 09263177
- Availability:
- Ships Same Business Day
- Weight:
- 0.46 LBS
- SPRING LIFT:
- 0,420'
- SPRING SEAT PRESSURE:
- 69 LB
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- SPRING LIFT IMPERIAL:
- 0.420'
- SPRING OPEN PRESSURE:
- 187 LB
- TYPE:
- CONVERSION
- UNITS:
- KIT
$172.15Qty in Cart: 0Quantity:Price:$172.15Subtotal: -
KIBBLEWHITE Intake Valve 80-82312
KIBBLEWHITE
$31.01Black 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.09263178- SKU:
- 09263178
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- STEM DIAMETER IMPERIAL:
- 0.1962'
- HEAD DIAMETER METRIC:
- 31.00 MM
- LENGTH IMPERIAL:
- 3.245'
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- OFF-ROAD
- TULIP ANGLE:
- 18°
- APPLICATION:
- INTAKE
- MODEL:
- BLACK DIAMOND™
- UNITS:
- EACH
$31.01 -
On Sale
KIBBLEWHITE Valve Spring Kit 82-83400
KIBBLEWHITE
MSRP: $355.95Now: $228.00Was: $355.95Black 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...09263295- SKU:
- 09263295
- Availability:
- Ships Same Business Day
- Weight:
- 1.25 LBS
- APPLICATION:
- INTAKE
- PRODUCT NAME:
- SPRING KIT
- RIDING STYLE:
- ATV
- SPRING LIFT IMPERIAL:
- 0.450'
- MATERIAL:
- TITANIUM
- MATERIAL:
- VITON
- SPRING SEAT PRESSURE:
- 64 LB
- APPLICATION:
- EXHAUST
- SPRING OPEN PRESSURE:
- 181 LB
- TYPE:
- VALVE
- MATERIAL:
- HIGH TENSILE STEEL
- SPRING LIFT:
- 0,450'
- UNITS:
- KIT
MSRP: $355.95Now: $228.00Was: $355.95Qty in Cart: 0Quantity:Price:MSRP: $355.95Now: $228.00Was: $355.95Subtotal: -
KIBBLEWHITE Cylinder Head Service Kit 30-33460
KIBBLEWHITE
$403.24Kits contain all items to completely refresh and upgrade cylinder heads for popular Dirt/MX and Side x Side models, Cylinder Head Service Kits include the below components:, Lightweight Racing Valve Spring kits with steel or titanium retainers, beehive...09263225- SKU:
- 09263225
- Availability:
- Ships Same Business Day
- Weight:
- 2.71 LBS
- APPLICATION:
- EXHAUST
- MATERIAL:
- TITANIUM
- SPRING LIFT:
- 0,300'
- MATERIAL:
- C630 BRONZE
- SPRING OPEN PRESSURE:
- 157 LB
- UNITS:
- KIT
- APPLICATION:
- INTAKE
- MODEL:
- BLACK DIAMOND™
- PRODUCT NAME:
- CYLINDER HEAD SERVICE KIT
- RIDING STYLE:
- ATV
- SPRING LIFT IMPERIAL:
- 0.300'
- SPRING SEAT PRESSURE:
- 70 LB
$403.24Qty in Cart: 0Quantity:Price:$403.24Subtotal: -
KIBBLEWHITE Piston System 30-32500
KIBBLEWHITE
$660.02The only safe way to maximize compression; the valve reliefs in the piston are purposely convex and match the geometry of the dishes in the valves, Conversion to Black Diamond™ stainless steel valves offers up to twice the life of the stock titanium...09031586- SKU:
- 09031586
- Availability:
- Ships Same Business Day
- Weight:
- 1.91 LBS
- BORE SIZE METRIC:
- 94.00 MM
- PRODUCT NAME:
- SERVICE KIT
- RIDING STYLE:
- ATV
- UNITS:
- KIT
- TYPE:
- TOP END
$660.02Qty in Cart: 0Quantity:Price:$660.02Subtotal: -
KIBBLEWHITE Intake Valve - CRF150R - Standard 30-30910
KIBBLEWHITE
$37.55Black 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.09260298- SKU:
- 09260298
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- MODEL:
- BLACK DIAMOND™
- STEM DIAMETER IMPERIAL:
- 0.1765'
- MATERIAL:
- STAINLESS STEEL
- PRODUCT NAME:
- VALVE
- APPLICATION:
- INTAKE
- TULIP ANGLE:
- 19°
- UNITS:
- EACH
- HEAD DIAMETER METRIC:
- 26.00 MM
- LENGTH IMPERIAL:
- 3.065'
- RIDING STYLE:
- OFF-ROAD
$37.55Qty in Cart: 0Quantity:Price:$37.55Subtotal: -
KIBBLEWHITE Intake Valve 40-40412
KIBBLEWHITE
$31.01Black 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.09261649- SKU:
- 09261649
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
- RIDING STYLE:
- UTV
- APPLICATION:
- INTAKE
- HEAD DIAMETER METRIC:
- 30.00 MM
- MATERIAL:
- STAINLESS STEEL
- MODEL:
- BLACK DIAMOND™
- PRODUCT NAME:
- VALVE
- LENGTH IMPERIAL:
- 3.600'
- RIDING STYLE:
- ATV
- STEM DIAMETER IMPERIAL:
- 0.1960'
- TULIP ANGLE:
- 10°
- UNITS:
- EACH
$31.01 -
KIBBLEWHITE Exhaust Valve Guide 96-96280
KIBBLEWHITE
$24.89All 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.09261716- SKU:
- 09261716
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- INSIDE DIAMETER IMPERIAL:
- 0.1960'
- MATERIAL:
- C630 BRONZE
- SIZE IMPERIAL:
- STANDARD
- UNITS:
- EACH
- APPLICATION:
- EXHAUST
- OUTSIDE DIAMETER IMPERIAL:
- 0.3958'
- PRODUCT NAME:
- VALVE GUIDE
- RIDING STYLE:
- OFF-ROAD
$24.89 -
JE PISTONS Piston Kit 132699
JE PISTONS
$269.99Machined from 2618-T6 high-tensile forged aluminum, Dome/dish features smooth flowing radii; requires no deburring or preparation, Specifically engineered for extreme applications including professional competition, Pro Series pistons available for...09105837- SKU:
- 09105837
- Availability:
- Ships Same Business Day
- Weight:
- 1.21 LBS
- BORE - OVERSIZE METRIC:
- +1.00 MM
- PISTON HEAD SHAPE:
- DOMED
- STYLE:
- JE PISTON
- TYPE:
- ROUND FORGED DESIGN
- UNITS:
- KIT
- BORE - OVERSIZE:
- +1,00 MM
- DISPLACEMENT:
- 406 CC
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- ATV
- BORE SIZE METRIC:
- 86.00 MM
- COMPRESSION RATIO IMPERIAL:
- 10.6:1
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
$269.99 -
JE PISTONS Piston Kit 247607
JE PISTONS
$309.99Machined from 2618-T6 high-tensile forged aluminum, Dome/dish features smooth flowing radii; requires no deburring or preparation, Specifically engineered for extreme applications including professional competition, Pro Series pistons available for...09105852- SKU:
- 09105852
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- BORE - OVERSIZE:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- PRO SERIES
- UNITS:
- KIT
- TYPE:
- FORGED SIDE RELIEF DESIGN
- COMPRESSION RATIO IMPERIAL:
- 13.2:1
- PISTON HEAD SHAPE:
- DOMED
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 78.00 MM
- DISPLACEMENT:
- 249 CC
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- PRODUCT NAME:
- PISTON KIT
$309.99Qty in Cart: 0Quantity:Price:$309.99Subtotal: -
JE PISTONS Piston Kit 300277
JE PISTONS
$269.99Machined from 2618-T6 high-tensile forged aluminum, Dome/dish features smooth flowing radii; requires no deburring or preparation, Specifically engineered for extreme applications including professional competition, Pro Series pistons available for...09105914- SKU:
- 09105914
- Availability:
- Ships Same Business Day
- Weight:
- 1.50 LBS
- BORE - OVERSIZE:
- +2,00 MM
- BORE - OVERSIZE METRIC:
- +2.00 MM
- BORE SIZE METRIC:
- 102.00 MM
- COMPRESSION RATIO IMPERIAL:
- 10.5:1
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- STYLE:
- JE PISTON
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- ROUND FORGED DESIGN
- UNITS:
- KIT
- DISPLACEMENT:
- 657 CC
- PISTON HEAD SHAPE:
- FLAT TOP
$269.99Qty in Cart: 0Quantity:Price:$269.99Subtotal: -
On Sale
DRAG SPECIALTIES Pistons - M8 21900049-020
DRAG SPECIALTIES
MSRP: $136.95Now: $88.00Was: $136.95Piston for M8 models09110052- SKU:
- 09110052
- Availability:
- Ships Same Business Day
- Weight:
- 2.40 LBS
- BORE OVERSIZE - IMPERIAL:
- +0.020'
- BORE SIZE IMPERIAL:
- 3.937'
- COMPRESSION RATIO IMPERIAL:
- 10.0:1
- DISPLACEMENT:
- 107'
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- CAST
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- BORE - OVERSIZE:
- +0,020'
- UNITS:
- KIT
MSRP: $136.95Now: $88.00Was: $136.95Qty in Cart: 0Quantity:Price:MSRP: $136.95Now: $88.00Was: $136.95Subtotal: -
On Sale
Cylinder Works Big Bore Gasket Kit Honda CRF250R 2004-2009 11001-G01
CYLINDER WORKS
MSRP: $64.95Now: $58.46Was: $64.95Enhance your engine's performance with the CYLINDER WORKS Big Bore Gasket Kit 11001-G01. Designed for easy installation, this kit features high-quality components that replicate OEM specifications while boosting your bike's power and efficiency...09341521- SKU:
- 09341521
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- TOP END
- BORE SIZE METRIC:
- OVERSIZED (+3.00 MM)
- MATERIAL:
- NICKEL SILICON CARBIDE
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- BIG BORE
MSRP: $64.95Now: $58.46Was: $64.95Qty in Cart: 0Quantity:Price:MSRP: $64.95Now: $58.46Was: $64.95Subtotal: -
On Sale
ATHENA Water Pump Gasket Kit - Yamaha P400485475005
ATHENA
MSRP: $34.95Now: $31.00Was: $34.95Include water pump gasket, clutch cover gasket, water pump shaft oil seals and washers, Kit contents will vary slightly based on application, Kits do not contain replacement bearings09346087- SKU:
- 09346087
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- TYPE:
- WATER PUMP
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- GASKET KIT
MSRP: $34.95Now: $31.00Was: $34.95 -
ACERBIS X-Power Cover Kit - Blue - Yamaha 2780680211
ACERBIS
$76.95Engine crankcase and Ignition/clutch cover, Protects against dirt, debris and impact, Installs easily with stock crankcase and Ignition/clutch cover bolts, Molded openings for easy access to oil cap and filter cover, Heat resistant; won't interfere with...09401894- SKU:
- 09401894
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
- MATERIAL:
- PLASTIC
- PRODUCT NAME:
- COVER KIT
- MODEL:
- X-POWER
- PRODUCT NAME:
- COVER
- TYPE:
- ENGINE
- COLOR/FINISH:
- BLUE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$76.95Qty in Cart: 0Quantity:Price:$76.95Subtotal: -
JAGG OIL COOLERS Universal 6-Row Oil Cooler with Tabs 3050
JAGG OIL COOLERS
$184.95Jagg Universal Oil Cooler Cores are the very same oil coolers that are used in high-quality Jagg kits, These units are perfect for the customizer, the fabricator, and the racer, Supplied as oil cooler only, Mounting hardware sold separately07130205- SKU:
- 07130205
- Availability:
- Ships Same Business Day
- Weight:
- 1.20 LBS
- BASE COLOR:
- BLACK
- MOUNTING POSITION:
- TOP
- UNITS:
- EACH
- BASE FINISH:
- POWDER-COATED
- COLOR/FINISH:
- GLOSS
- RIDING STYLE:
- STREET
- COLOR/FINISH:
- BLACK
- MOUNTING STYLE:
- TABS
- PRODUCT NAME:
- OIL COOLER
- STYLE:
- STRAIGHT
- TYPE:
- 6-ROW
$184.95Qty in Cart: 0Quantity:Price:$184.95Subtotal: -
JAGG OIL COOLERS Universal 6-Row Oil Cooler 3090
JAGG OIL COOLERS
$184.95Jagg Universal Oil Cooler Cores are the very same oil coolers that are used in high-quality Jagg kits, These units are perfect for the customizer, the fabricator, and the racer, Supplied as oil cooler only, Mounting hardware sold separately07130207- SKU:
- 07130207
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
- BASE FINISH:
- POWDER-COATED
- RIDING STYLE:
- STREET
- BASE COLOR:
- BLACK
- UNITS:
- EACH
- COLOR/FINISH:
- BLACK
- COLOR/FINISH:
- GLOSS
- TYPE:
- 6-ROW
- MOUNTING POSITION:
- BOTTOM
- MOUNTING STYLE:
- BOLT-ON
- PRODUCT NAME:
- OIL COOLER
- STYLE:
- 90°
$184.95Qty in Cart: 0Quantity:Price:$184.95Subtotal:
