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
-
On Sale
KIBBLEWHITE Exhaust Valve 80-81316
KIBBLEWHITE
MSRP: $37.55Now: $33.80Was: $37.55Exhaust valves endure extreme temperatures and constant cycling—factory originals wear quickly under high-performance demands. The KIBBLEWHITE Black Diamond™ valve delivers the durability and...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
MSRP: $37.55Now: $33.80Was: $37.55Qty in Cart: 0Quantity:Price:MSRP: $37.55Now: $33.80Was: $37.55Subtotal: -
On Sale
KIBBLEWHITE Intake Valve Kit 40-41450
KIBBLEWHITE
MSRP: $185.23Now: $166.71Was: $185.23If you're running high-RPM applications or endurance racing, valve degradation is one of the quickest paths to catastrophic engine failure. The KIBBLEWHITE 40-41450 Intake Valve Kit replaces stock...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'
MSRP: $185.23Now: $166.71Was: $185.23Qty in Cart: 0Quantity:Price:MSRP: $185.23Now: $166.71Was: $185.23Subtotal: -
On Sale
KIBBLEWHITE Valve Guide 96-96521
KIBBLEWHITE
MSRP: $24.89Now: $22.40Was: $24.89Valve guide wear is one of the quickest ways to lose compression, increase oil consumption, and compromise engine reliability. The KIBBLEWHITE 96-96521 valve guide delivers the thermal management and...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
MSRP: $24.89Now: $22.40Was: $24.89Qty in Cart: 0Quantity:Price:MSRP: $24.89Now: $22.40Was: $24.89Subtotal: -
On Sale
KIBBLEWHITE Valve Conversion Kit 80-82350
KIBBLEWHITE
MSRP: $172.15Now: $154.94Was: $172.15If you're running your engine hard, OEM titanium intake valves will only take you so far before thermal fatigue and wear force a costly rebuild. The KIBBLEWHITE Valve Conversion Kit replaces them...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
MSRP: $172.15Now: $154.94Was: $172.15Qty in Cart: 0Quantity:Price:MSRP: $172.15Now: $154.94Was: $172.15Subtotal: -
On Sale
KIBBLEWHITE Intake Valve 80-82312
KIBBLEWHITE
MSRP: $31.01Now: $27.91Was: $31.01If you're building or rebuilding an engine that demands reliability under sustained high RPM operation, intake valve quality directly impacts combustion efficiency and longevity. The KIBBLEWHITE...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
MSRP: $31.01Now: $27.91Was: $31.01 -
On Sale
KIBBLEWHITE Cylinder Head Service Kit 30-33460
KIBBLEWHITE
MSRP: $431.48Now: $362.92Was: $431.48A complete top-end refresh requires precision components engineered to withstand the demands of high-RPM racing. The KIBBLEWHITE Cylinder Head Service Kit 30-33460 consolidates every critical...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
MSRP: $431.48Now: $362.92Was: $431.48 -
On Sale
KIBBLEWHITE Piston System 30-32500
KIBBLEWHITE
MSRP: $660.02Now: $594.02Was: $660.02If you're chasing higher compression ratios without sacrificing reliability, the KIBBLEWHITE Piston System 30-32500 is engineered specifically for that purpose. The convex valve reliefs match your...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
MSRP: $660.02Now: $594.02Was: $660.02Qty in Cart: 0Quantity:Price:MSRP: $660.02Now: $594.02Was: $660.02Subtotal: -
On Sale
KIBBLEWHITE Intake Valve - CRF150R - Standard 30-30910
KIBBLEWHITE
MSRP: $37.55Now: $33.80Was: $37.55OEM valves wear down with hard use, causing compression loss and throttle response lag that compounds over time. The Kibblewhite Black Diamond™ intake valve restores full flow efficiency while...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
MSRP: $37.55Now: $33.80Was: $37.55 -
On Sale
KIBBLEWHITE Intake Valve 40-40412
KIBBLEWHITE
MSRP: $35.22Now: $27.91Was: $35.22Kibblewhite's Black Diamond™ intake valves are engineered for engines that demand precision and longevity. Built from EV8 stainless steel forgings, these valves deliver reduced friction and...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
MSRP: $35.22Now: $27.91Was: $35.22 -
On Sale
KIBBLEWHITE Exhaust Valve Guide 96-96280
KIBBLEWHITE
MSRP: $24.89Now: $22.40Was: $24.89Valve guide wear is one of the most common culprits behind oil consumption, loss of compression, and erratic idle in high-performance engines. The KIBBLEWHITE Exhaust Valve Guide 96-96280 replaces...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
MSRP: $24.89Now: $22.40Was: $24.89 -
JE PISTONS Piston Kit 132699
JE PISTONS
$283.99If you're building an engine for the track, your pistons need to survive extreme pressures, high RPM loads, and unforgiving competition environments. JE PISTONS' 2618-T6 forged aluminum construction...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
$283.99 -
JE PISTONS Piston Kit 247607
JE PISTONS
$309.99When you're pushing your engine to the limit in professional competition, piston failure isn't an option—it's a catastrophe. JE PISTONS 247607 kits are purpose-built for extreme applications where...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
$269.99When you're pushing your engine to the absolute limit, your pistons need to handle extreme pressures and temperatures without compromise. JE Pistons' Pro Series 300277 kit delivers the precision...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: -
Cylinder Works Big Bore Gasket Kit Honda CRF250R 2004-2009 11001-G01
CYLINDER WORKS
$64.95If you're running a Honda CRF250R and serious about extracting more power from your engine, a big bore kit is one of the most direct paths to measurable performance gains. The Cylinder Works Big Bore...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
$64.95Qty in Cart: 0Quantity:Price:$64.95Subtotal: -
On Sale
ATHENA Water Pump Gasket Kit - Yamaha P400485475005
ATHENA
MSRP: $36.95Now: $31.00Was: $36.95A failing water pump gasket can compromise your entire cooling system, leading to overheating, performance loss, and catastrophic engine damage. The ATHENA Water Pump Gasket Kit gives you...09346087- 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: $36.95Now: $31.00Was: $36.95 -
ACERBIS X-Power Cover Kit - Blue - Yamaha 2780680211
ACERBIS
$76.95Crankcase and ignition cover damage can sideline your bike mid-season—dirt ingestion, rock strikes, and UV degradation are real threats to engine longevity. The ACERBIS X-Power Cover Kit shields your...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
$76.95 -
JAGG OIL COOLERS Universal 6-Row Oil Cooler with Tabs 3050
JAGG OIL COOLERS
$184.95Engine oil temperature is critical to performance and longevity—especially under sustained racing conditions or aggressive driving. The JAGG 6-Row Oil Cooler with Tabs delivers efficient thermal...07130205- 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
$184.95Excessive oil temperatures compromise engine performance, reduce component lifespan, and risk catastrophic failure under sustained load. The JAGG 3090 Universal 6-Row Oil Cooler delivers efficient...07130207- 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: -
JAGG OIL COOLERS Universal 6-Row Oil Cooler 3100
JAGG OIL COOLERS
$184.95Engine oil temperature is critical to performance longevity and power output, and stock cooling systems often fall short under sustained track use or high-boost conditions. The JAGG Universal 6-Row...07130208- SKU:
- 07130208
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
- MOUNTING POSITION:
- TOP
- MOUNTING STYLE:
- BOLT-ON
- PRODUCT NAME:
- OIL COOLER
- STYLE:
- 90°
- BASE COLOR:
- BLACK
- UNITS:
- EACH
- COLOR/FINISH:
- BLACK
- TYPE:
- 6-ROW
- BASE FINISH:
- POWDER-COATED
- COLOR/FINISH:
- GLOSS
- RIDING STYLE:
- STREET
$184.95Qty in Cart: 0Quantity:Price:$184.95Subtotal: -
JAGG OIL COOLERS Universal 6-Row Oil Cooler 3110
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...07130209- SKU:
- 07130209
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
- MOUNTING STYLE:
- BOLT-ON
- COLOR/FINISH:
- BLACK
- MOUNTING POSITION:
- BOTTOM
- PRODUCT NAME:
- OIL COOLER
- TYPE:
- 6-ROW
- BASE COLOR:
- BLACK
- STYLE:
- STRAIGHT
- BASE FINISH:
- POWDER-COATED
- COLOR/FINISH:
- GLOSS
- RIDING STYLE:
- STREET
- UNITS:
- EACH
$184.95Qty in Cart: 0Quantity:Price:$184.95Subtotal:
