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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On Sale
COMETIC Top End Gasket Set - Gas Gas C3261
COMETIC
MSRP: $56.95Now: $51.26Was: $56.95A failed top-end gasket will strand you on the track or trail, compromising compression and power when you need it most. The COMETIC C3261 Top End Gasket Set delivers the sealing integrity demanded...09344128- SKU:
- 09344128
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
MSRP: $56.95Now: $51.26Was: $56.95 -
Hot Cams Cam Chain for Kawasaki KX450F 2006-2008 and KLX450R 2008-2009 HC98XRH2010124
HOT CAMS
$62.95A worn or undersized cam chain compromises valve timing precision and can lead to catastrophic engine damage—especially in high-revving four-stroke applications like the KX450F and KLX450R. The HOT...09250765- SKU:
- 09250765
- Availability:
- Ships Same Business Day
- Weight:
- 0.51 LBS
- MODEL:
- SILENT
- RIDING STYLE:
- STREET
- BASE FINISH:
- RAW
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CAM
- CHAIN SIZE:
- 98XRH2010
- PRODUCT NAME:
- CHAIN
- COLOR/FINISH:
- RAW
- MATERIAL:
- STEEL
- UNITS:
- EACH
$62.95 -
Hot Cams Cam Chain for Husqvarna FC450 2016-2018 and KTM 450 SX-F 2016-2018 HC92RH2015108
HOT CAMS
$77.95A worn or failing cam chain compromises valve timing and engine reliability—especially critical in high-stress racing and performance applications. The HOT CAMS HC92RH2015108 delivers heat-treated...09250822- SKU:
- 09250822
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- BASE FINISH:
- RAW
- CHAIN SIZE:
- 92RH2015
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- CHAIN
- MODEL:
- SILENT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CAM
- COLOR/FINISH:
- RAW
- MATERIAL:
- STEEL
- UNITS:
- EACH
$77.95 -
VERTEX Piston Ring 590281000001
VERTEX
$80.95Worn piston rings compromise compression, increase blowby, and rob your engine of power and efficiency. VERTEX Piston Ring 590281000001 restores ring sealing to factory specifications, whether you're...09120309- SKU:
- 09120309
- Availability:
- Ships Same Business Day
- Weight:
- 0.07 LBS
- PISTON DIAMETER METRIC:
- 80.98 MM
- UNITS:
- SET
- PRODUCT NAME:
- PISTON RING
- RIDING STYLE:
- OFF-ROAD
$80.95 -
VERTEX Wrist Pin - CR/YZ/SX/KX/RM 715372
VERTEX
$9.95Wrist pin failure under high RPM can cost you races and damage your engine. The VERTEX 715372 uses nitride-coated case hardening to eliminate wear and galling while maintaining dimensional...09130038- SKU:
- 09130038
- Availability:
- Ships Same Business Day
- Weight:
- 0.12 LBS
- APPLICATION:
- PISTON
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- WRIST PIN
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
$9.95 -
VERTEX Piston Ring 53010006400
VERTEX
$35.95Piston rings are critical wear items that directly impact engine compression, blow-by control, and overall performance—worn or damaged rings will cost you power and reliability. The VERTEX Piston...09120174- SKU:
- 09120174
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- PISTON DIAMETER METRIC:
- 63.95 MM
- PRODUCT NAME:
- PISTON RING
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$35.95 -
VERTEX Piston Ring 53010006640
VERTEX
$44.95Piston rings are critical wear items that directly impact compression, blow-by, and overall engine efficiency. The VERTEX Piston Ring 53010006640 delivers extended durability through advanced surface...09120175- SKU:
- 09120175
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- PISTON RING
- UNITS:
- EACH
- PISTON DIAMETER METRIC:
- 66.36 MM
$44.95 -
Wiseco Ring Set 48mm Honda CRF70F 2004-2012 1890XE
WISECO
$46.95Piston ring sets are critical to maintaining proper compression and cylinder sealing—worn or damaged rings lead to blowby, power loss, and accelerated engine wear. The Wiseco 1890XE is engineered...09120114- SKU:
- 09120114
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- PISTON RING
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 48.00 MM
- DISPLACEMENT:
- 48 CC
- UNITS:
- SET
- PISTON MATERIAL:
- ALUMINUM
$46.95 -
Wiseco Valve Kit 2007-2008 Kawasaki KX250F SVKB4336
WISECO
$365.95Valve wear is one of the most common failure points in high-revving two-stroke engines, directly impacting combustion efficiency and overall power delivery. The Wiseco Valve Kit SVKB4336 replaces...09263076- SKU:
- 09263076
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- APPLICATION:
- EXHAUST
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$365.95 -
Wiseco Piston Kit 47mm Bore Yamaha YZ80 1975 222M04700
WISECO
$138.95Whether you're prepping your YZ80 for weekend racing or maximizing reliability on the trail, a quality piston kit is fundamental to engine longevity and power output. Wiseco's high-silicon alloy...222M04700- SKU:
- 222M04700
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- BORE SIZE METRIC:
- 47.00 MM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- MODEL:
- FORGED SERIES
- PISTON DIAMETER METRIC:
- 46.95 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- SKIRT COATING:
- NON-COATED
- STROKE LENGTH METRIC:
- 42.00 MM
- DISPLACEMENT:
- 72 CC
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$138.95 -
Wiseco Piston Kit 49.50mm Oversize for Suzuki RM80 1977-1981 456M04950
WISECO
$135.95If you're rebuilding or refreshing your RM80's top end, piston choice directly impacts combustion efficiency, ring sealing, and overall engine longevity. Wiseco's high-silicon alloy construction...456M04950- SKU:
- 456M04950
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
- BORE - OVERSIZE:
- +0,50 MM
- PISTON DIAMETER METRIC:
- 49.45 MM
- SKIRT COATING:
- NON-COATED
- UNITS:
- KIT
- MODEL:
- FORGED SERIES
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- STROKE LENGTH METRIC:
- 42.00 MM
- BORE SIZE METRIC:
- 49.50 MM
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- BORE - OVERSIZE METRIC:
- +0.50 MM
- DISPLACEMENT:
- 79 CC
$135.95 -
On Sale
Wossner Piston Kit 94.96mm 12.3:1 Compression Yamaha YZ450F 2006-2009 8630DA
WOSSNER
MSRP: $204.00Now: $193.80Was: $204.00The stock piston in your YZ450F experiences extreme thermal and mechanical stress during high-RPM operation, leading to power loss and accelerated wear. The Wossner 8630DA replaces this weak link...09104950- SKU:
- 09104950
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- MODEL:
- STANDARD SERIES
- PRODUCT NAME:
- PISTON KIT
- BORE SIZE METRIC:
- 95.00 MM
- PISTON SIZE METRIC:
- 94.96 MM
- BORE - OVERSIZE:
- STANDARD
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- COMPRESSION RATIO IMPERIAL:
- 12.3:1
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $204.00Now: $193.80Was: $204.00 -
On Sale
COMETIC Top End Gasket Set - Suzuki C7136
COMETIC
MSRP: $40.95Now: $36.86Was: $40.95A failing head gasket compromises combustion sealing and bleeds horsepower—especially under boost or high cylinder pressures. The COMETIC C7136 Top End Gasket Set delivers multi-layered steel...C7136- SKU:
- C7136
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- TYPE:
- TOP END
- PRODUCT NAME:
- GASKET KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $40.95Now: $36.86Was: $40.95 -
Wiseco Piston 1.00mm Oversize for 2004 Honda CR125R 676M05500
WISECO
$143.95If you're running a 2004 Honda CR125R at the edge of its limits, a worn or damaged piston directly costs you compression, power, and reliability. The Wiseco Piston 676M05500 restores your engine's...676M05500- SKU:
- 676M05500
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- BORE - OVERSIZE:
- +1,00 MM
- BORE SIZE METRIC:
- 55.00 MM
- PISTON MATERIAL:
- FORGED
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 54.50 MM
- BORE - OVERSIZE METRIC:
- +1.00 MM
- ENGINE TYPE:
- 2-STROKE
- STROKE LENGTH:
- 54,50 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
- DISPLACEMENT:
- 125 CC
- PRODUCT NAME:
- PISTON
$143.95 -
Wiseco Piston Kit 54mm for Kawasaki KX125 1994 640M05400
WISECO
$162.95If you're running a KX125 and want measurable gains in compression ratio and power delivery, a quality piston kit is non-negotiable. The Wiseco +.50mm piston gives you that precision-forged...652M05450- SKU:
- 652M05450
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- BORE - OVERSIZE:
- +0,50 MM
- PRODUCT NAME:
- PISTON
- PISTON MATERIAL:
- FORGED
- STROKE LENGTH METRIC:
- 54.50 MM
- BORE SIZE METRIC:
- 54.50 MM
- ENGINE TYPE:
- 2-STROKE
- STROKE LENGTH:
- 54,50 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- DISPLACEMENT:
- 124 CC
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$162.95 -
Wiseco Piston Kit +1.00 mm Kawasaki KX 80 1991-1997 644M04900
WISECO
$143.95If you're running a Kawasaki KX80 and want to restore lost compression or chase more peak power, a quality piston kit is non-negotiable. The Wiseco 644M04900 delivers the precision fit and material...644M04900- SKU:
- 644M04900
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- BORE - OVERSIZE METRIC:
- +1.00 MM
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
- BORE SIZE METRIC:
- 49.00 MM
- DISPLACEMENT:
- 82 CC
- STROKE LENGTH:
- 45,80 MM
- BORE - OVERSIZE:
- +1,00 MM
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 45.80 MM
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
$143.95 -
Wiseco Piston 1.50mm Oversize Honda CR250R 2001 614M06800
WISECO
$232.95Worn or damaged pistons rob your CR250R of power and reliability. This Wiseco piston kit restores combustion efficiency and throttle response with precision-engineered construction built to survive...614M06800- SKU:
- 614M06800
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- BORE - OVERSIZE METRIC:
- +1.60 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- UNITS:
- EACH
- DISPLACEMENT:
- 249 CC
- STROKE LENGTH:
- 72,00 MM
- BORE SIZE METRIC:
- 68.00 MM
- PRODUCT NAME:
- PISTON
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 72.00 MM
- BORE - OVERSIZE:
- +1,60 MM
$232.95 -
Wiseco Piston Kit 85mm 10:1 Compression for Honda TRX400EX 1999-2008 4606M08500
WISECO
$210.95The Honda TRX400EX demands a piston that can handle sustained high-RPM abuse while maintaining reliable power delivery—the Wiseco 4606M08500 delivers exactly that. With a 10:1 compression ratio and...4606M08500- SKU:
- 4606M08500
- Availability:
- Ships Same Business Day
- Weight:
- 0.94 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- COMPRESSION RATIO IMPERIAL:
- 10.0:1
- DISPLACEMENT:
- 397 CC
- RIDING STYLE:
- OFF-ROAD
- SKIRT COATING:
- NON-COATED
- UNITS:
- KIT
- MODEL:
- FORGED SERIES
- PISTON DIAMETER METRIC:
- 84.95 MM
- BORE - OVERSIZE:
- STANDARD
- ENGINE TYPE:
- 4-STROKE
- RIDING STYLE:
- ATV
- BORE SIZE METRIC:
- 85.00 MM
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- STROKE LENGTH METRIC:
- 70.00 MM
$210.95 -
Wiseco Piston Kit 1mm Oversize 76.95mm 10.5:1 Compression Honda XL250R 1984-1987 4329M07600
WISECO
$194.95If you're rebuilding a Honda XL250R or XR250R engine, this Wiseco piston kit delivers the bore size and compression ratio needed for reliable power restoration or modest performance gains. The 1mm...4329M07600- SKU:
- 4329M07600
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- BORE - OVERSIZE METRIC:
- +1.00 MM
- RIDING STYLE:
- OFF-ROAD
- SKIRT COATING:
- NON-COATED
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 10.5:1
- ENGINE TYPE:
- 4-STROKE
- BORE - OVERSIZE:
- +1,00 MM
- BORE SIZE METRIC:
- 76.00 MM
- DISPLACEMENT:
- 250 CC
- MODEL:
- FORGED SERIES
- PRODUCT NAME:
- PISTON KIT
- PISTON DIAMETER METRIC:
- 75.95 MM
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- STROKE LENGTH METRIC:
- 56.50 MM
$194.95 -
HOT RODS Connecting Rod 8129
HOT RODS
$135.95When you're pushing your engine to the limit, your connecting rods need to handle extreme loads and sustained high-RPM operation without compromise. The HOT RODS 8129 is engineered for engines that...423108- SKU:
- 423108
- Availability:
- Ships Same Business Day
- Weight:
- 0.81 LBS
- ENGINE TYPE:
- 2-CYCLE
- MATERIAL:
- 8620 STEEL
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- FEATURES:
- INCLUDES THRUST WASHERS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$135.95
