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!
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- Qty in Cart
- Quantity
- Price
- Subtotal
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KIBBLEWHITE Intake Valve 96-96005
KIBBLEWHITE
$37.55Intake valve performance directly impacts your engine's breathing efficiency and power delivery—a worn or inferior valve compromises combustion quality and throttle response. KIBBLEWHITE's Black Diamond™ intake valves are engineered from premium EV8...09261698- SKU:
- 09261698
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- HEAD DIAMETER METRIC:
- 36.00 MM
- MATERIAL:
- STAINLESS STEEL
- MODEL:
- BLACK DIAMOND™
- PRODUCT NAME:
- VALVE
- LENGTH IMPERIAL:
- 3.815'
- UNITS:
- EACH
- APPLICATION:
- INTAKE
- RIDING STYLE:
- OFF-ROAD
- STEM DIAMETER IMPERIAL:
- 0.2350'
- TULIP ANGLE:
- 20°
$37.55 -
KIBBLEWHITE Exhaust Valve 96-96007
KIBBLEWHITE
$37.55Valve degradation under extreme combustion temperatures is one of the fastest ways to lose power and reliability in a high-performance engine. The KIBBLEWHITE Black Diamond™ Exhaust Valve delivers the durability and precision needed to withstand repeated...09261699- SKU:
- 09261699
- Availability:
- Ships Same Business Day
- Weight:
- 0.09 LBS
- MODEL:
- BLACK DIAMOND™
- STEM DIAMETER IMPERIAL:
- 0.2342'
- UNITS:
- EACH
- APPLICATION:
- EXHAUST
- LENGTH IMPERIAL:
- 3.815'
- MATERIAL:
- STAINLESS STEEL
- PRODUCT NAME:
- VALVE
- TULIP ANGLE:
- 24°
- HEAD DIAMETER METRIC:
- 30.00 MM
- RIDING STYLE:
- OFF-ROAD
$37.55 -
KIBBLEWHITE Exhaust Valve 96-96008
KIBBLEWHITE
$37.55Exhaust valves are among the most thermally stressed and wear-prone components in your engine—they need to withstand extreme temperatures, corrosive combustion byproducts, and thousands of cycles per minute. The KIBBLEWHITE Black Diamond™ exhaust valve...09261700- SKU:
- 09261700
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- LENGTH IMPERIAL:
- 3.815'
- STEM DIAMETER IMPERIAL:
- 0.2342'
- MATERIAL:
- STAINLESS STEEL
- MODEL:
- BLACK DIAMOND™
- HEAD DIAMETER METRIC:
- 21.00 MM
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- VALVE
- TULIP ANGLE:
- 24°
- UNITS:
- EACH
$37.55 -
KIBBLEWHITE Intake Valve Guide 96-96010
KIBBLEWHITE
$22.29Valve guide wear is one of the most common causes of oil consumption and performance degradation in high-mileage engines. The KIBBLEWHITE Intake Valve Guide 96-96010 replaces worn guides with a precision-engineered component that restores proper valve...09261701- SKU:
- 09261701
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- PRODUCT NAME:
- VALVE GUIDE
- MATERIAL:
- C630 BRONZE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- INSIDE DIAMETER IMPERIAL:
- 0.2360'
- SIZE IMPERIAL:
- STANDARD
- APPLICATION:
- INTAKE
- OUTSIDE DIAMETER IMPERIAL:
- 0.4745'
$22.29 -
KIBBLEWHITE Exhaust Valve Guide 96-96020
KIBBLEWHITE
$22.29Valve guide wear is a silent killer of engine performance, causing increased oil consumption, blow-by, and eventual catastrophic valve failure. The KIBBLEWHITE Exhaust Valve Guide 96-96020 is precision-engineered from Ampco-45, a copper-nickel compound...09261702- SKU:
- 09261702
- Availability:
- Ships Same Business Day
- Weight:
- 0.07 LBS
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- VALVE GUIDE
- MATERIAL:
- C630 BRONZE
- OUTSIDE DIAMETER IMPERIAL:
- 0.4745'
- APPLICATION:
- EXHAUST
- INSIDE DIAMETER IMPERIAL:
- 0.2360'
- SIZE IMPERIAL:
- STANDARD
- UNITS:
- EACH
$22.29 -
KIBBLEWHITE Exhaust Valve 96-96266
KIBBLEWHITE
$54.10Your engine's exhaust valves endure extreme temperatures and constant stress—factory components often fall short under high-performance demands. The KIBBLEWHITE Black Diamond™ Exhaust Valve delivers the durability and reliability you need for sustained...09261713- SKU:
- 09261713
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- MATERIAL:
- STAINLESS STEEL
- MODEL:
- BLACK DIAMOND™
- STEM DIAMETER IMPERIAL:
- 0.1955'
- TULIP ANGLE:
- 30°
- UNITS:
- EACH
- APPLICATION:
- EXHAUST
- HEAD DIAMETER METRIC:
- 26.60 MM
- LENGTH IMPERIAL:
- 3.665'
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- OFF-ROAD
$54.10 -
KIBBLEWHITE Intake Valve Guide 96-96270
KIBBLEWHITE
$24.89Valve guide wear is one of the most common failure points in high-revving and forced-induction engines, leading to oil consumption, compression loss, and costly engine rebuilds. The KIBBLEWHITE Intake Valve Guide 96-96270 replaces worn guides with...09261715- SKU:
- 09261715
- Availability:
- Ships Same Business Day
- Weight:
- 0.04 LBS
- SIZE IMPERIAL:
- STANDARD
- UNITS:
- EACH
- APPLICATION:
- INTAKE
- OUTSIDE DIAMETER IMPERIAL:
- 0.3958'
- PRODUCT NAME:
- VALVE GUIDE
- INSIDE DIAMETER IMPERIAL:
- 0.1960'
- MATERIAL:
- C630 BRONZE
- RIDING STYLE:
- OFF-ROAD
$24.89 -
KIBBLEWHITE Intake Valve Guide 30-30730
KIBBLEWHITE
$15.92Your engine's intake valves endure extreme temperatures and constant stress, making quality valve guides essential to maintaining proper sealing and preventing wear that can compromise compression and performance. KIBBLEWHITE's Ampco-45 construction...09300019- SKU:
- 09300019
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- MATERIAL:
- AMPCO-45
- INSIDE DIAMETER IMPERIAL:
- 0.2155'
- OUTSIDE DIAMETER IMPERIAL:
- 0.4360'
- APPLICATION:
- INTAKE
- PRODUCT NAME:
- VALVE GUIDE
- RIDING STYLE:
- ATV
- UNITS:
- EACH
$15.92 -
KIBBLEWHITE Exhaust Valve Guide 30-30740
KIBBLEWHITE
$15.92Valve guides are critical components that direct oil flow and maintain precise valve alignment under extreme combustion pressures. The KIBBLEWHITE 30-30740 exhaust valve guide uses Ampco-45, a specialized copper-nickel alloy engineered specifically for...09300021- SKU:
- 09300021
- Availability:
- Ships Same Business Day
- Weight:
- 0.03 LBS
- INSIDE DIAMETER IMPERIAL:
- 0.2150'
- APPLICATION:
- EXHAUST
- OUTSIDE DIAMETER IMPERIAL:
- 0.4360'
- MATERIAL:
- AMPCO-45
- PRODUCT NAME:
- VALVE GUIDE
- RIDING STYLE:
- ATV
- UNITS:
- EACH
$15.92 -
On Sale
JAMES GASKET Alternator Cap Cover O-ring ST-11900029
JAMES GASKET
MSRP: $6.95Now: $4.00Was: $6.95Alternator cap cover o-rings are critical sealing components that prevent moisture, dirt, and debris from compromising your alternator's internal windings and electrical connections. A deteriorated or missing o-ring can lead to corrosion, voltage...09351073- SKU:
- 09351073
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- APPLICATION:
- ALTERNATOR CAP
- PRODUCT NAME:
- O-RING
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
MSRP: $6.95Now: $4.00Was: $6.95 -
On Sale
JAMES GASKET Clutch Actuator Shaft O-ring ST-11900030
JAMES GASKET
MSRP: $3.95Now: $3.00Was: $3.95A worn or degraded clutch actuator shaft o-ring compromises hydraulic pressure and leads to inconsistent clutch engagement—a critical issue for reliable operation. This genuine JAMES GASKET replacement restores proper sealing, ensuring crisp clutch feel...09351074- SKU:
- 09351074
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- APPLICATION:
- CLUTCH
- PRODUCT NAME:
- O-RING
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
MSRP: $3.95Now: $3.00Was: $3.95 -
On Sale
JAMES GASKET Thermostat O-Ring 10969
JAMES GASKET
Now: $4.00Was: $6.20A failing thermostat o-ring is one of the easiest ways to develop coolant leaks that go undetected until serious engine damage occurs. The JAMES GASKET Thermostat O-Ring 10969 is a precision-engineered replacement that restores a reliable seal at the...09351087- SKU:
- 09351087
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- TYPE:
- THERMOSTAT
- PRODUCT NAME:
- O-RING
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
Now: $4.00Was: $6.20 -
On Sale
JAMES GASKET Cylinder Head Gasket ST-16500085
JAMES GASKET
MSRP: $97.95Now: $63.00Was: $97.95A quality cylinder head gasket is critical to maintaining combustion sealing and preventing costly coolant or oil leaks. The JAMES GASKET ST-16500085 is a genuine OEM-equivalent kit engineered to factory specifications, ensuring reliable performance...09346474- SKU:
- 09346474
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
- MATERIAL:
- -
- RIDING STYLE:
- STREET
- THICKNESS IMPERIAL:
- 0,045'
- BORE SIZE:
- STANDARD
- BORE SIZE IMPERIAL:
- STANDARD
- TYPE:
- CYLINDER HEAD
- PRODUCT NAME:
- GASKET
- THICKNESS METRIC:
- 1.14 MM
- UNITS:
- 2 PACK
MSRP: $97.95Now: $63.00Was: $97.95 -
On Sale
JAMES GASKET Cam Chain Tensioner Gasket ST-25500005
JAMES GASKET
MSRP: $48.95Now: $31.00Was: $48.95A failing cam chain tensioner gasket will compromise your engine's internal sealing integrity and lead to costly oil leakage and potential timing chain wear. The JAMES GASKET ST-25500005 delivers a reliable, factory-quality replacement that restores...09346478- SKU:
- 09346478
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- UNITS:
- 2 PACK
- TYPE:
- CAM CHAIN TENSIONER
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- STREET
MSRP: $48.95Now: $31.00Was: $48.95 -
On Sale
JAMES GASKET Complete Motor Gasket Kit ST-25700443
JAMES GASKET
MSRP: $217.95Now: $139.00Was: $217.95A complete engine rebuild demands precision sealing across every critical junction—oil passages, combustion chambers, and bearing surfaces. This JAMES GASKET kit delivers OEM-quality gaskets, oil seals, and o-rings in one package, eliminating the...09346483- SKU:
- 09346483
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
- BORE SIZE METRIC:
- 69.00 MM
- UNITS:
- KIT
- BORE SIZE:
- 69,00 MM
- RIDING STYLE:
- STREET
- THICKNESS IMPERIAL:
- 0.045'
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- ENGINE
MSRP: $217.95Now: $139.00Was: $217.95 -
On Sale
JAMES GASKET Breather Baffle Gasket ST-29400074
JAMES GASKET
MSRP: $40.95Now: $26.00Was: $40.95A properly functioning breather system is critical to engine longevity and performance—excessive crankcase pressure leads to seal failure, oil leaks, and reduced reliability. The JAMES GASKET Breather Baffle Gasket ST-29400074 ensures a tight, dependable...09346485- SKU:
- 09346485
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- PRODUCT NAME:
- GASKET
- TYPE:
- BREATHER
- UNITS:
- 2 PACK
- RIDING STYLE:
- STREET
MSRP: $40.95Now: $26.00Was: $40.95 -
On Sale
JAMES GASKET Valve Cover - Grommet ST-6114-15
JAMES GASKET
MSRP: $19.95Now: $13.00Was: $19.95A properly sealed valve cover is critical to preventing oil leakage and maintaining clean engine bay conditions. The JAMES GASKET Valve Cover Grommet ST-6114-15 delivers reliable, long-lasting sealing performance with precision engineering and domestic...09346486- SKU:
- 09346486
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- PRODUCT NAME:
- GROMMET
- RIDING STYLE:
- STREET
- TYPE:
- VALVE COVER
- UNITS:
- 10 PACK
MSRP: $19.95Now: $13.00Was: $19.95 -
JE PISTONS Piston Kit 345192
JE PISTONS
$839.99When you're pushing your engine to the limits in professional competition, your pistons need to handle extreme pressures and temperatures without compromise. JE PISTONS 345192 kits are engineered specifically for forced induction and high-boost...09105946- SKU:
- 09105946
- Availability:
- Ships Same Business Day
- Weight:
- 2.91 LBS
- BORE SIZE METRIC:
- 80.00 MM
- PRODUCT NAME:
- PISTON KIT
- WALL THICKNESS:
- 0,160'
- DISPLACEMENT:
- 998 CC
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 9.5:1
- PISTON HEAD SHAPE:
- DISHED
- RIDING STYLE:
- UTV
- WALL THICKNESS IMPERIAL:
- 0.160'
$839.99 -
JE PISTONS Piston Kit 128996
JE PISTONS
$269.99When you're pushing an engine to its absolute limit, stock pistons simply won't cut it. JE PISTONS' Pro Series 128996 kit is engineered specifically for professional competition and extreme applications, delivering the reliability and precision you need...09105832- SKU:
- 09105832
- Availability:
- Ships Same Business Day
- Weight:
- 1.50 LBS
- BORE - OVERSIZE:
- +4,00 MM
- PISTON HEAD SHAPE:
- FLAT TOP
- BORE - OVERSIZE METRIC:
- +4.00 MM
- BORE SIZE METRIC:
- 101.00 MM
- COMPRESSION RATIO IMPERIAL:
- 10.6:1
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- ROUND FORGED DESIGN
- UNITS:
- KIT
- DISPLACEMENT:
- 640 CC
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- STYLE:
- JE PISTON
$269.99 -
JE PISTONS Piston Kit 128998
JE PISTONS
$269.99If you're pushing your engine to the limit in competition or high-performance applications, your pistons need to match that commitment. JE PISTONS' Pro Series 128998 kit delivers the precision engineering and durability required for extreme racing...09105833- SKU:
- 09105833
- Availability:
- Ships Same Business Day
- Weight:
- 1.55 LBS
- BORE - OVERSIZE:
- +5,00 MM
- BORE SIZE METRIC:
- 102.00 MM
- PRODUCT NAME:
- PISTON KIT
- DISPLACEMENT:
- 654 CC
- PISTON HEAD SHAPE:
- FLAT TOP
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- STYLE:
- JE PISTON
- COMPRESSION RATIO IMPERIAL:
- 10.8:1
- TYPE:
- ROUND FORGED DESIGN
- UNITS:
- KIT
- BORE - OVERSIZE METRIC:
- +5.00 MM
- RIDING STYLE:
- OFF-ROAD
$269.99
