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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Wiseco Piston Kit Honda CR85R 2003-2007 833M04850
WISECO
$119.95The Wiseco 833M04850 is a precision-engineered piston kit built for 2-stroke engines that demand consistent power delivery and reliability. If you're serious about maintaining peak performance in...09101253- SKU:
- 09101253
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
- BORE SIZE METRIC:
- 48.50 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- ENGINE TYPE:
- 2-STROKE
- MODEL:
- PRO-LITE
- BORE - OVERSIZE METRIC:
- +1.00 MM
- PISTON MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- STROKE LENGTH METRIC:
- 47.80 MM
- BORE - OVERSIZE:
- +1,00 MM
- DISPLACEMENT:
- 84,7 CC
- PISTON MATERIAL:
- FORGED
$119.95Qty in Cart: 0Quantity:Price:$119.95Subtotal: -
Wiseco Piston Kit Yamaha YZ125 2005-2021 846M05800
WISECO
$210.95The piston is the heart of your YZ125's engine—responsible for transferring combustion force into usable power. A worn or stock piston limits your bike's potential, reducing compression efficiency...09101255- SKU:
- 09101255
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- BORE - OVERSIZE METRIC:
- +4.00 MM
- BORE SIZE METRIC:
- 58.00 MM
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- SKIRT COATING:
- ARMORGLIDE®
- DISPLACEMENT:
- 144 CC
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
- STROKE LENGTH METRIC:
- 54.50 MM
- BORE - OVERSIZE:
- +4,00 MM
- ENGINE TYPE:
- 2-STROKE
- MODEL:
- GP STYLE
- RIDING STYLE:
- OFF-ROAD
$210.95 -
Wiseco Piston Kit 90.5mm 1.5mm Oversize Honda CR500R 1984-2001 871M09050
WISECO
$255.95The Wiseco 871M09050 delivers the compression and durability required to extract maximum power from your CR500R while maintaining reliability through extended high-rpm operation. Built with...09102025- SKU:
- 09102025
- Availability:
- Ships Same Business Day
- Weight:
- 1.30 LBS
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- SKIRT COATING:
- ARMORGLIDE®
- STROKE LENGTH METRIC:
- 76.00 MM
- UNITS:
- EACH
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- OFF-ROAD
- BORE - OVERSIZE METRIC:
- +1.50 MM
- BORE SIZE METRIC:
- 90.50 MM
- ENGINE TYPE:
- 2-STROKE
- BORE - OVERSIZE:
- +1,50 MM
- DISPLACEMENT:
- 508 CC
$255.95Qty in Cart: 0Quantity:Price:$255.95Subtotal: -
Wiseco Piston Kit Standard 41mm for Kawasaki KFX50 2003-2009 826M04100
WISECO
$121.95If you're running a KFX50 and want reliable power without compromise, the Wiseco 826M04100 Piston Kit delivers the precision engineering needed for consistent performance across racing and trail...09100339- SKU:
- 09100339
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- BORE SIZE METRIC:
- 41.00 MM
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- STROKE LENGTH METRIC:
- 37.80 MM
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
- DISPLACEMENT:
- 49 CC
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
$121.95 -
Wiseco Piston Kit 41.50 mm Oversize for Kawasaki KFX 50 2003-2009 826M04150
WISECO
$104.95When you're rebuilding a 2-stroke engine, piston quality directly impacts power delivery, engine longevity, and overall reliability. The Wiseco 826M04150 delivers precision-engineered performance...09100340- SKU:
- 09100340
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- BORE - OVERSIZE METRIC:
- +0.50 MM
- ENGINE TYPE:
- 2-STROKE
- STROKE LENGTH METRIC:
- 37.80 MM
- BORE - OVERSIZE:
- +0,50 MM
- DISPLACEMENT:
- 49 CC
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 41.50 MM
$104.95Qty in Cart: 0Quantity:Price:$104.95Subtotal: -
Wiseco Piston Kit 42.00 mm Oversize Kawasaki KFX50 2003-2009 Suzuki JR50 1978-2006 826M04200
WISECO
$104.95When you're pushing a 2-stroke engine to its limits, a worn or undersized piston compromises compression, throttle response, and reliability. The Wiseco 826M04200 restores lost performance and...09100341- SKU:
- 09100341
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- DISPLACEMENT:
- 49 CC
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
- BORE - OVERSIZE METRIC:
- +1.00 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
- BORE SIZE METRIC:
- 42.00 MM
- STROKE LENGTH METRIC:
- 37.80 MM
- BORE - OVERSIZE:
- +1,00 MM
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
$104.95Qty in Cart: 0Quantity:Price:$104.95Subtotal: -
Wiseco Piston Kit 43.00 mm Oversize for Kawasaki KFX 50 2003-2009 826M04300
WISECO
$109.95When you're ready to push your KFX 50 past factory limits, a quality piston kit is non-negotiable. Wiseco's 826M04300 delivers the precision engineering and durability needed for serious ride...09100343- SKU:
- 09100343
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- BORE - OVERSIZE METRIC:
- +2.00 MM
- DISPLACEMENT:
- 49 CC
- ENGINE TYPE:
- 2-STROKE
- STROKE LENGTH METRIC:
- 37.80 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- BORE SIZE METRIC:
- 43.00 MM
- PISTON MATERIAL:
- FORGED
- RIDING STYLE:
- OFF-ROAD
- BORE - OVERSIZE:
- +2,00 MM
- PRODUCT NAME:
- PISTON
$109.95Qty in Cart: 0Quantity:Price:$109.95Subtotal: -
Wiseco Piston Kit 54.50 mm Kawasaki KX100 1995-2013 Suzuki RM100 2003 651M05450
WISECO
$139.95When your 2-stroke engine is the difference between winning and second place, every component matters. The Wiseco 651M05450 Pro-Lite Piston Kit delivers the precision engineering and thermal...09100345- SKU:
- 09100345
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
- BORE SIZE METRIC:
- 54.50 MM
- STROKE LENGTH METRIC:
- 45.80 MM
- BORE - OVERSIZE METRIC:
- +2.00 MM
- ENGINE TYPE:
- 2-STROKE
- BORE - OVERSIZE:
- +2,00 MM
- DISPLACEMENT:
- 99 CC
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- RIDING STYLE:
- OFF-ROAD
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
$139.95Qty in Cart: 0Quantity:Price:$139.95Subtotal: -
Wiseco Piston Kit Kawasaki KX125 2004-2008 56.00 mm 2.00 mm Oversize 834M05600
WISECO
$174.95A worn or stock piston limits your KX125's potential—this Wiseco Pro-Lite kit restores compression, throttle response, and engine longevity with precision-engineered components built for 2-stroke...09100347- SKU:
- 09100347
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- STROKE LENGTH METRIC:
- 54.50 MM
- BORE - OVERSIZE METRIC:
- +2.00 MM
- ENGINE TYPE:
- 2-STROKE
- BORE - OVERSIZE:
- +2,00 MM
- BORE SIZE METRIC:
- 56.00 MM
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- RIDING STYLE:
- OFF-ROAD
- DISPLACEMENT:
- 133 CC
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
$174.95 -
Wiseco Piston Kit 77mm 13.1:1 Compression for 2004-2005 Kawasaki KX250F 2004-2006 Suzuki RM-Z250 4842M07700
WISECO
$224.95If you're rebuilding a KX250F or RM-Z250 engine or pushing for higher output on the track, a quality piston kit is non-negotiable. The Wiseco 4842M07700 delivers the compression ratio and material...09100354- SKU:
- 09100354
- Availability:
- Ships Same Business Day
- Weight:
- 0.53 LBS
- BORE SIZE METRIC:
- 77.00 MM
- DISPLACEMENT:
- 250 CC
- PISTON MATERIAL:
- FORGED
- STROKE LENGTH METRIC:
- 53.60 MM
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- PRODUCT NAME:
- PISTON
- SKIRT COATING:
- ARMORGLIDE®
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$224.95Qty in Cart: 0Quantity:Price:$224.95Subtotal: -
Wiseco Piston Kit 77.00mm 14.1:1 Compression Kawasaki KX250F 2004-2005 Suzuki RM-Z250 2004-2006 4843M07700
WISECO
$264.95If you're running a KX250F or RM-Z250 and want measurable gains in peak power and mid-range response, a high-compression piston kit is one of the most direct bolt-on upgrades available. The Wiseco...09100356- SKU:
- 09100356
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- BORE - OVERSIZE:
- STANDARD
- BORE SIZE METRIC:
- 77.00 MM
- DISPLACEMENT:
- 250 CC
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- STROKE LENGTH METRIC:
- 53.60 MM
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
$264.95 -
Wiseco RM125 2004-2007 Piston Kit 2.00mm Oversize 835M05600
WISECO
$177.95If you're running a 2004-2007 Suzuki RM125 and need to restore lost compression or step up displacement for more mid-range power, a quality piston kit is non-negotiable. The Wiseco 835M05600 delivers...09100358- SKU:
- 09100358
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
- BORE - OVERSIZE:
- +2,00 MM
- BORE SIZE METRIC:
- 56.00 MM
- PRODUCT NAME:
- PISTON
- PISTON MATERIAL:
- FORGED
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 54.50 MM
- ENGINE TYPE:
- 2-STROKE
- MODEL:
- PRO-LITE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
- BORE - OVERSIZE METRIC:
- +2.00 MM
- DISPLACEMENT:
- 134 CC
$177.95Qty in Cart: 0Quantity:Price:$177.95Subtotal: -
Wiseco Piston Kit 58mm 11:1 Compression for 2003-2006 Kawasaki KLX125 4815M05800
WISECO
$154.95If you're running a KLX125 and want measurable gains in acceleration and reliability, an 11:1 compression piston kit is one of the most effective upgrades available. The Wiseco 4815M05800 delivers...09100361- SKU:
- 09100361
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- BORE - OVERSIZE METRIC:
- +1.00 MM
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- STROKE LENGTH METRIC:
- 48.80 MM
- UNITS:
- EACH
- COMPRESSION RATIO IMPERIAL:
- 11.0:1
- BORE - OVERSIZE:
- +1,00 MM
- BORE SIZE METRIC:
- 58.00 MM
- DISPLACEMENT:
- 125 CC
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
$154.95Qty in Cart: 0Quantity:Price:$154.95Subtotal: -
Wiseco Piston Kit 46.50mm for Kawasaki KX65 2000-2020 and Suzuki RM65 2003-2005 PK1179
WISECO
$186.95Top-end wear is inevitable on high-performance 2-stroke machines, but a worn piston kit kills compression, power delivery, and reliability when you need it most. The Wiseco PK1179 restores your KX65...09030514- SKU:
- 09030514
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- BORE - OVERSIZE:
- +2,00 MM
- BORE SIZE METRIC:
- 46.50 MM
- PISTON SIZE METRIC:
- +2.00 MM
- PRODUCT NAME:
- REBUILD KIT
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 41.60 MM
- UNITS:
- KIT
- BORE - OVERSIZE METRIC:
- +2.00 MM
- DISPLACEMENT:
- 64 CC
- ENGINE TYPE:
- 2-STROKE
- MODEL:
- PRO-LITE
- PISTON DIAMETER METRIC:
- 46.45 MM
- TYPE:
- TOP END
- SKIRT COATING:
- NON-COATED
$186.95Qty in Cart: 0Quantity:Price:$186.95Subtotal: -
Wiseco Piston Kit 54.50mm for Kawasaki KX100 1998-2013 PK1156
WISECO
$220.95If you're running a Kawasaki KX100 and want reliable top-end performance that actually delivers, a quality piston kit isn't optional—it's essential. The Wiseco PK1156 gives you forged pistons...09030515- SKU:
- 09030515
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- DISPLACEMENT:
- 99 CC
- PISTON SIZE METRIC:
- +2.00 MM
- PRODUCT NAME:
- REBUILD KIT
- BORE - OVERSIZE:
- +2,00 MM
- BORE - OVERSIZE METRIC:
- +2.00 MM
- ENGINE TYPE:
- 2-STROKE
- MODEL:
- PRO-LITE
- PISTON DIAMETER METRIC:
- 54.45 MM
- TYPE:
- TOP END
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 45.80 MM
- BORE SIZE METRIC:
- 54.50 MM
- SKIRT COATING:
- NON-COATED
- UNITS:
- KIT
$220.95 -
Wiseco Piston Kit 97mm 13.5:1 Compression for 2007-2012 KTM 450 SX-F 4938M09700
WISECO
$284.95If you're running a KTM 450 SX-F or XC-F and want measurable gains in power and throttle response, a quality piston kit is one of the highest-impact upgrades you can make. The Wiseco 4938M09700...09100851- SKU:
- 09100851
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 60.80 MM
- DISPLACEMENT:
- 449 CC
- BORE - OVERSIZE:
- STANDARD
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 97.00 MM
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- SKIRT COATING:
- MOLY COATED
$284.95Qty in Cart: 0Quantity:Price:$284.95Subtotal: -
Wiseco Suzuki RM85 2002-2023 48.50mm Piston Kit PK1207
WISECO
$186.95A properly rebuilt top end is non-negotiable for RM85 reliability and performance. The Wiseco PK1207 delivers the precision-engineered pistons and complete gasket set you need to restore compression,...09030544- SKU:
- 09030544
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- BORE - OVERSIZE:
- +0,50 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE SIZE METRIC:
- 48.50 MM
- ENGINE TYPE:
- 2-STROKE
- MODEL:
- PRO-LITE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
- STROKE LENGTH METRIC:
- 46.80 MM
- DISPLACEMENT:
- 84.7 CC
- PRODUCT NAME:
- REBUILD KIT
- PISTON DIAMETER METRIC:
- 48.45 MM
- SKIRT COATING:
- ARMORGLIDE®
$186.95Qty in Cart: 0Quantity:Price:$186.95Subtotal: -
Wiseco Piston Kit for Honda CR250R 2005-2007 66.40mm PK1381
WISECO
$309.95The Wiseco PK1381 is engineered for CR250R riders who need a proven top-end rebuild that restores or exceeds factory performance. If you're experiencing power loss, worn compression, or simply demand...09030550- SKU:
- 09030550
- Availability:
- Ships Same Business Day
- Weight:
- 1.44 LBS
- COOLING SYSTEM:
- LIQUID COOLED
- DISPLACEMENT:
- 249 CC
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 66.40 MM
- MODEL:
- RACER'S CHOICE
- PISTON MATERIAL:
- ALUMINUM
- PISTON MATERIAL:
- FORGED
- UNITS:
- EACH
- PRODUCT NAME:
- REBUILD KIT
- STROKE LENGTH METRIC:
- 72.00 MM
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
$309.95Qty in Cart: 0Quantity:Price:$309.95Subtotal: -
Wiseco Honda CRF450R 2002-2008 Piston Kit PK1233
WISECO
$390.95When you're rebuilding a CRF450R top end, you need a piston kit that matches the precision your engine demands. The Wiseco PK1233 delivers the bore accuracy and compression ratio necessary for...09030552- SKU:
- 09030552
- Availability:
- Ships Same Business Day
- Weight:
- 1.55 LBS
- BORE SIZE METRIC:
- 96.00 MM
- MODEL:
- FORGED SERIES
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- DISPLACEMENT:
- 449 CC
- PISTON DIAMETER METRIC:
- 95.94 MM
- SKIRT COATING:
- ARMORGLIDE®
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- PRODUCT NAME:
- REBUILD KIT
- STROKE LENGTH METRIC:
- 62.10 MM
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- 2618 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
$390.95 -
Wiseco Piston Kit 77mm 13.1:1 for 2004-2005 Kawasaki KX250F PK1237
WISECO
$308.95A complete top-end rebuild demands precision components that can handle sustained high RPMs and aggressive tuning. The Wiseco PK1237 delivers race-proven engineering in a bolt-together package,...09030555- SKU:
- 09030555
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON MATERIAL:
- 2618 ALUMINUM ALLOY
- PRODUCT NAME:
- REBUILD KIT
- BORE - OVERSIZE:
- STANDARD
- BORE SIZE METRIC:
- 77.00 MM
- DISPLACEMENT:
- 250 CC
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- FORGED SERIES
- SKIRT COATING:
- NON-COATED
- STROKE LENGTH METRIC:
- 53.60 MM
- COMPRESSION RATIO IMPERIAL:
- 13.1:1
- PISTON DIAMETER METRIC:
- 76.96 MM
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
$308.95Qty in Cart: 0Quantity:Price:$308.95Subtotal:
