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
-
HOT RODS Crankshaft Kit CBK0124
HOT RODS
$768.95If you're building a high-performance engine or refreshing a tired crankshaft, the HOT RODS Crankshaft Kit CBK0124 delivers factory-matched reliability with performance that meets or exceeds OEM...09210358- SKU:
- 09210358
- Availability:
- Ships Same Business Day
- Weight:
- 13.08 LBS
- TYPE:
- OEM
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- CRANKSHAFT KIT
- UNITS:
- KIT
$768.95 -
HOT RODS Crankshaft 4068
HOT RODS
$150.95If you're building a long-stroke engine for your ATV, you need a crankshaft engineered specifically for the application—not a compromised OEM unit that limits potential. The HOT RODS Crankshaft 4068...09210076- SKU:
- 09210076
- Availability:
- Ships Same Business Day
- Weight:
- 4.78 LBS
- COLOR/FINISH:
- STEEL
- DISPLACEMENT:
- 85 CC
- MATERIAL:
- 4140 STEEL
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 48.00 MM
- UNITS:
- ASSEMBLY
- MODEL:
- 2-CYCLE
- FEATURES:
- STANDARD CRANKSHAFT
- TYPE:
- OEM STROKE
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
$150.95 -
HOT RODS Crankshaft - Stroker 4166
HOT RODS
$316.95A stroker crankshaft transforms your ATV's engine into a powerhouse by increasing displacement and torque output without sacrificing reliability. The HOT RODS 4166 eliminates the machine work and...09210077- SKU:
- 09210077
- Availability:
- Ships Same Business Day
- Weight:
- 4.60 LBS
- COLOR/FINISH:
- STEEL
- DISPLACEMENT:
- 88 CC TO 103.5 CC
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- ASSEMBLY
- MATERIAL:
- 4140 STEEL
- MODEL:
- 2-CYCLE
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- STROKE LENGTH:
- 47,80 MM
- STROKE LENGTH METRIC:
- 47.80 MM
- FEATURES:
- STANDARD CRANKSHAFT
- TYPE:
- STROKER
$316.95 -
On Sale
COMETIC Clutch Cover Gasket - Kawasaki EC513018AFM
COMETIC
MSRP: $13.95Now: $12.56Was: $13.95A failing clutch cover gasket compromises engine sealing and can lead to oil weeping, contamination, and catastrophic drivetrain failure. The COMETIC Clutch Cover Gasket (EC513018AFM) is engineered...09345456- SKU:
- 09345456
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- PRODUCT NAME:
- GASKET
- UNITS:
- SET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH COVER
MSRP: $13.95Now: $12.56Was: $13.95Qty in Cart: 0Quantity:Price:MSRP: $13.95Now: $12.56Was: $13.95Subtotal: -
On Sale
COMETIC Top End Gasket Set - Yamaha C3105
COMETIC
MSRP: $41.95Now: $37.76Was: $41.95A factory gasket set won't cut it when you're running high boost or aggressive naturally aspirated power levels—combustion pressure and heat cycles will compromise the seal and kill your horsepower...09343427- SKU:
- 09343427
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- UNITS:
- KIT
- PRODUCT NAME:
- GASKET KIT
- TYPE:
- TOP END
- RIDING STYLE:
- OFF-ROAD
MSRP: $41.95Now: $37.76Was: $41.95 -
Hot Cams Stage 1 Camshaft for Yamaha TTR125E 2003-2009 4019-1
HOT CAMS
$252.95If you're running a TTR125E in competitive or high-performance riding conditions, factory cam timing limits your acceleration and throttle responsiveness. The Hot Cams Stage 1 transforms low-end...TTR125S1A- SKU:
- TTR125S1A
- Availability:
- Ships Same Business Day
- Weight:
- 0.70 LBS
- APPLICATION:
- INTAKE
- INTAKE DURATION IMPERIAL:
- 227°
- INTAKE LIFT METRIC:
- 6.80 MM
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- CAMSHAFT
- EXHAUST DURATION IMPERIAL:
- 223°
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- STAGE 1
- UNITS:
- EACH
- EXHAUST LIFT METRIC:
- 5.90 MM
$252.95Qty in Cart: 0Quantity:Price:$252.95Subtotal: -
Hot Cams Stage 1 Camshaft for Honda CRF100F 2004-2013 1018-1
HOT CAMS
$244.95If you're running a CRF100F and want measurable gains in low-end torque without sacrificing reliability, the Hot Cams Stage 1 Camshaft is a straightforward bolt-on upgrade that delivers real power...XR100S1A- SKU:
- XR100S1A
- Availability:
- Ships Same Business Day
- Weight:
- 0.70 LBS
- EXHAUST LIFT METRIC:
- 5.90 MM
- TYPE:
- STAGE 1
- APPLICATION:
- EXHAUST
- INTAKE DURATION IMPERIAL:
- 236°
- INTAKE LIFT METRIC:
- 6.80 MM
- PRODUCT NAME:
- CAMSHAFT
- APPLICATION:
- INTAKE
- EXHAUST DURATION IMPERIAL:
- 216°
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$244.95 -
Hot Cams Stage 1 Camshaft for 1996-2004 Honda XR250R 1006-1
HOT CAMS
$377.95The Hot Cams Stage 1 Camshaft transforms your XR250R's powerband by optimizing valve timing for responsive low-end torque—ideal if you're looking for improved throttle feel without major engine work...XR250S1A- SKU:
- XR250S1A
- Availability:
- Ships Same Business Day
- Weight:
- 1.16 LBS
- INTAKE LIFT METRIC:
- 9.00 MM
- APPLICATION:
- INTAKE
- EXHAUST DURATION IMPERIAL:
- 236°
- TYPE:
- STAGE 1
- UNITS:
- EACH
- APPLICATION:
- EXHAUST
- EXHAUST LIFT METRIC:
- 8.70 MM
- INTAKE DURATION IMPERIAL:
- 236°
- PRODUCT NAME:
- CAMSHAFT
- RIDING STYLE:
- OFF-ROAD
$377.95Qty in Cart: 0Quantity:Price:$377.95Subtotal: -
Hot Cams Stage 1 Camshaft for 1988-2000 Honda XR600R 1993-2009 Honda XR650L 1004-1
HOT CAMS
$311.95If you're running an XR600R or XR650L and want measurable gains in low-end pull and mid-range response, the Hot Cams Stage 1 is a straightforward bolt-on upgrade that delivers real-world performance...XR600S1A- SKU:
- XR600S1A
- Availability:
- Ships Same Business Day
- Weight:
- 1.25 LBS
- INTAKE DURATION IMPERIAL:
- 258°
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- INTAKE
- EXHAUST DURATION IMPERIAL:
- 258°
- UNITS:
- EACH
- INTAKE LIFT METRIC:
- 8.80 MM
- PRODUCT NAME:
- CAMSHAFT
- APPLICATION:
- EXHAUST
- EXHAUST LIFT METRIC:
- 8.80 MM
- TYPE:
- STAGE 1
$311.95 -
Hot Cams Stage 2 Intake Camshaft for 2011-2016 Kawasaki KX250F 2220-2IN
HOT CAMS
$294.95If you're serious about extracting maximum performance from your KX250F, camshaft selection is where gains are made. The Hot Cams Stage 2 Intake Camshaft delivers measurable improvements in peak...09250663- SKU:
- 09250663
- Availability:
- Ships Same Business Day
- Weight:
- 0.83 LBS
- PRODUCT NAME:
- CAMSHAFT
- APPLICATION:
- INTAKE
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
- INTAKE DURATION IMPERIAL:
- 245°
- INTAKE LIFT METRIC:
- 9.65 MM
- TYPE:
- STAGE 2
$294.95Qty in Cart: 0Quantity:Price:$294.95Subtotal: -
Hot Cams Stage 1 Camshaft for 2009 Honda CRF450R 1123-1
HOT CAMS
$403.95If you're running a 2009 Honda CRF450R and looking to unlock more usable torque without sacrificing reliability, the Hot Cams Stage 1 is the most straightforward bolt-on upgrade available. This...09250459- SKU:
- 09250459
- Availability:
- Ships Same Business Day
- Weight:
- 1.25 LBS
- INTAKE DURATION IMPERIAL:
- 235°
- APPLICATION:
- EXHAUST
- INTAKE LIFT METRIC:
- 9.60 MM
- PRODUCT NAME:
- CAMSHAFT
- TYPE:
- STAGE 1
- UNITS:
- EACH
- APPLICATION:
- INTAKE
- EXHAUST DURATION IMPERIAL:
- 248°
- EXHAUST LIFT METRIC:
- 8.70 MM
- RIDING STYLE:
- OFF-ROAD
$403.95Qty in Cart: 0Quantity:Price:$403.95Subtotal: -
Hot Cams Cam Chain Honda TRX700XX 2008-2009 HC92RH2010120
HOT CAMS
$50.95The cam chain is critical to your TRX700XX's valve timing and engine reliability—any wear or slack directly impacts performance and can lead to costly engine damage. HOT CAMS' heat-treated silent...09251169- SKU:
- 09251169
- Availability:
- Ships Same Business Day
- Weight:
- 0.41 LBS
- BASE FINISH:
- RAW
- RIDING STYLE:
- STREET
- COLOR/FINISH:
- RAW
- MATERIAL:
- STEEL
- MODEL:
- SILENT
- CHAIN SIZE:
- 92RH2010
- PRODUCT NAME:
- CHAIN
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CAM
- UNITS:
- EACH
$50.95 -
Hot Cams Stage 1 Intake Camshaft for 2017-2019 Kawasaki KX250F 2311-1IN
HOT CAMS
$264.95The stock camshaft in your KX250F limits what your engine can truly deliver. Hot Cams Stage 1 intake cam unlocks mid-range torque and throttle response that transforms acceleration without requiring...09251242- SKU:
- 09251242
- Availability:
- Ships Same Business Day
- Weight:
- 0.86 LBS
- PRODUCT NAME:
- CAMSHAFT
- TYPE:
- STAGE 1
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- INTAKE
- INTAKE DURATION IMPERIAL:
- 242°
- INTAKE LIFT METRIC:
- 9.90 MM
- UNITS:
- EACH
$264.95 -
Hot Cams Valve Shim 9.48mm x 2.55mm for Honda CRF450R 2002-2009 5PK948255
HOT CAMS
$10.95Valve clearance directly impacts engine efficiency, combustion timing, and overall reliability—even small deviations can reduce power output or cause premature wear. The HOT CAMS Valve Shim 5-pack...09261399- SKU:
- 09261399
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 2.55 MM
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- MATERIAL:
- STEEL
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
$10.95 -
Hot Cams Valve Shim 9.48mm x 2.85mm 5PK948285
HOT CAMS
$10.95Valve clearance directly impacts combustion efficiency, engine longevity, and overall performance—and these Hot Cams shims let you dial in exact specifications without guesswork. Whether you're...09261405- SKU:
- 09261405
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- SNOW
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- STREET
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 2.85 MM
$10.95Qty in Cart: 0Quantity:Price:$10.95Subtotal: -
On Sale
PROX Piston Kit 01.1408.150
PROX
MSRP: $185.95Now: $158.00Was: $185.95When your engine demands reliability under extreme conditions, OEM-spec pistons are non-negotiable. The PROX Piston Kit 01.1408.150 delivers factory-matched performance with the precision engineering...09030820- SKU:
- 09030820
- Availability:
- Ships Same Business Day
- Weight:
- 1.34 LBS
- PISTON SIZE METRIC:
- +1.50 MM
- BORE SIZE METRIC:
- 90.50 MM
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- EACH
- PRODUCT NAME:
- PISTON KIT
MSRP: $185.95Now: $158.00Was: $185.95 -
VERTEX Piston Kit - Standard 22991A
VERTEX
$171.95Piston durability and engine longevity depend on materials that withstand extreme combustion pressures and thermal cycling. The VERTEX Piston Kit 22991A combines proprietary heat treatment with a...09100984- SKU:
- 09100984
- Availability:
- Ships Same Business Day
- Weight:
- 0.31 LBS
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- CAST
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- DISPLACEMENT:
- 105 CC
- PISTON DIAMETER METRIC:
- 51.95 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- CYLINDER DIAMETER METRIC:
- 52.00 MM
- STYLE:
- CAST REPLICA
$171.95 -
VERTEX Piston Kit 22532B
VERTEX
$197.95A quality piston kit is fundamental to engine reliability and performance—especially under high-load conditions where inferior materials fail. The VERTEX Piston Kit 22532B delivers the durability and...09100987- SKU:
- 09100987
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
- PISTON DIAMETER METRIC:
- 54.20 MM
- PRODUCT NAME:
- PISTON KIT
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- CYLINDER DIAMETER METRIC:
- 54.25 MM
- PISTON MATERIAL:
- CAST
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- DISPLACEMENT:
- 125 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- STYLE:
- CAST REPLICA
$197.95Qty in Cart: 0Quantity:Price:$197.95Subtotal: -
VERTEX Piston Kit - Standard 23383A
VERTEX
$217.95VERTEX pistons are engineered for consistent power delivery and extended engine life, making them the choice for builders who demand reliability under sustained high RPM operation. The T-5 heat...09100990- SKU:
- 09100990
- Availability:
- Ships Same Business Day
- Weight:
- 0.44 LBS
- COMPRESSION RATIO IMPERIAL:
- STANDARD
- STYLE:
- CAST REPLICA
- PISTON DIAMETER METRIC:
- 55.95 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- CYLINDER DIAMETER METRIC:
- 56.00 MM
- DISPLACEMENT:
- 144 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- CAST
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$217.95Qty in Cart: 0Quantity:Price:$217.95Subtotal: -
Wiseco Piston Kit Standard 77mm 13.5:1 Kawasaki KX250F 2011-2014 40019M07700
WISECO
$224.95When your KX250F's stock piston reaches its limit, a quality replacement isn't optional—it's essential for maintaining power delivery and engine longevity. The Wiseco 40019M07700 delivers the...09102895- SKU:
- 09102895
- Availability:
- Ships Same Business Day
- Weight:
- 0.54 LBS
- BORE - OVERSIZE:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 77.00 MM
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- STROKE LENGTH METRIC:
- 53.60 MM
- UNITS:
- EACH
- DISPLACEMENT:
- 250 CC
$224.95Qty in Cart: 0Quantity:Price:$224.95Subtotal:
