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 Yamaha RT100 1990-2000 52.00mm 771M05200
WISECO
$132.95A worn or damaged piston directly impacts your RT100's power delivery, fuel efficiency, and engine longevity. The Wiseco 771M05200 restores lost compression and combustion efficiency with...09100795- SKU:
- 09100795
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- DISPLACEMENT:
- 97 CC
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 52.00 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON
- STROKE LENGTH METRIC:
- 45.60 MM
- PISTON MATERIAL:
- FORGED
$132.95 -
Wiseco Yamaha RT100 1990-2000 Piston Kit 52.50mm 771M05250
WISECO
$132.95If your Yamaha RT100 is wearing its original piston, you're leaving performance on the table. The Wiseco 771M05250 replaces worn or damaged pistons with precision-engineered components that restore...09100796- SKU:
- 09100796
- Availability:
- Ships Same Business Day
- Weight:
- 0.44 LBS
- DISPLACEMENT:
- 99 CC
- PRODUCT NAME:
- PISTON
- PISTON MATERIAL:
- FORGED
- RIDING STYLE:
- OFF-ROAD
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE SIZE METRIC:
- 52.50 MM
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
- BORE - OVERSIZE:
- +0,50 MM
- STROKE LENGTH METRIC:
- 45.60 MM
$132.95Qty in Cart: 0Quantity:Price:$132.95Subtotal: -
Wiseco Piston Kit Yamaha RT100 1990-2000 53mm Bore 771M05300
WISECO
$132.95When your 2-stroke demands reliability under sustained high-RPM load, a quality piston kit separates weekend warriors from serious competitors. The Wiseco 771M05300 delivers aerospace-grade forged...09100797- SKU:
- 09100797
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- DISPLACEMENT:
- 101,00 CC
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
- BORE SIZE METRIC:
- 53.00 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
- BORE - OVERSIZE:
- +1,00 MM
- BORE - OVERSIZE METRIC:
- +1.00 MM
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 45.60 MM
$132.95Qty in Cart: 0Quantity:Price:$132.95Subtotal: -
Wiseco Piston Kit Standard Bore 54mm Yamaha YZ125 2005-2021 846M05400
WISECO
$174.95When your YZ125's original piston starts showing wear, power delivery suffers and reliability becomes a gamble. The Wiseco 846M05400 replaces it with aerospace-grade forged aluminum and precision...09100799- SKU:
- 09100799
- Availability:
- Ships Same Business Day
- Weight:
- 0.41 LBS
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON
- UNITS:
- EACH
- BORE SIZE METRIC:
- 54.00 MM
- DISPLACEMENT:
- 125 CC
- ENGINE TYPE:
- 2-STROKE
- MODEL:
- GP STYLE
- PISTON MATERIAL:
- FORGED
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 54.50 MM
$174.95Qty in Cart: 0Quantity:Price:$174.95Subtotal: -
Wiseco Piston Kit Standard Bore 77mm 12.5:1 Compression Yamaha YZ250F 2005-2007 4882M07700
WISECO
$174.95If you're running a YZ250F between 2005-2007, factory pistons won't cut it for sustained high-RPM performance or competitive riding. The Wiseco 4882M07700 delivers the compression ratio and material...09100808- SKU:
- 09100808
- Availability:
- Ships Same Business Day
- Weight:
- 0.58 LBS
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 77.00 MM
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- DISPLACEMENT:
- 250 CC
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- STROKE LENGTH METRIC:
- 53.60 MM
- UNITS:
- EACH
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON MATERIAL:
- FORGED
- PRODUCT NAME:
- PISTON
$174.95Qty in Cart: 0Quantity:Price:$174.95Subtotal: -
On Sale
Wossner Top End Bearing for 1986-2006 Kawasaki KDX200 N1016
WOSSNER
MSRP: $18.50Now: $17.58Was: $18.50The top-end bearing in your KDX200 endures constant high-speed stress, and a worn bearing compromises power delivery and can lead to catastrophic engine failure. This Wossner replacement restores...09240453- SKU:
- 09240453
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- APPLICATION:
- CONNECTING ROD
- OUTSIDE DIAMETER METRIC:
- 21 MM
- LENGTH METRIC:
- 19.5 MM
- TYPE:
- TOP END
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
- INSIDE DIAMETER METRIC:
- 16 MM
- PRODUCT NAME:
- BEARING
- RIDING STYLE:
- STREET
MSRP: $18.50Now: $17.58Was: $18.50 -
Wrench Rabbit Complete Engine Rebuild Kit for 2007-2009 Honda CRF150R WR101-177
WRENCH RABBIT
$867.95When your Honda CRF150R engine reaches the end of its service life, a complete rebuild is the most cost-effective path to restoring full performance and reliability. The Wrench Rabbit Engine Rebuild...09031305- SKU:
- 09031305
- Availability:
- Ships Same Business Day
- Weight:
- 10.80 LBS
- FEATURES:
- STANDARD COMPRESSION PISTON
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- ENGINE
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- WRENCH RABBIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$867.95 -
Wrench Rabbit Complete Engine Rebuild Kit for Honda CRF150R 2012-2016 WR101-178
WRENCH RABBIT
$867.95When your Honda CRF150R engine reaches the end of its service life, a complete rebuild kit eliminates the guesswork and ensures every critical component meets OEM specifications. The Wrench Rabbit...09031306- SKU:
- 09031306
- Availability:
- Ships Same Business Day
- Weight:
- 9.15 LBS
- TYPE:
- ENGINE
- FEATURES:
- STANDARD COMPRESSION PISTON
- PRODUCT NAME:
- REBUILD KIT
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- WRENCH RABBIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$867.95Qty in Cart: 0Quantity:Price:$867.95Subtotal: -
Wrench Rabbit Complete Engine Rebuild Kit for Honda CRF450X 2005-2009 2012-2016 WR101-179
WRENCH RABBIT
$1,132.95An engine rebuild is a critical investment in your Honda CRF450X's longevity and performance. The Wrench Rabbit Complete Engine Rebuild Kit eliminates guesswork by bundling every component you...09031307- SKU:
- 09031307
- Availability:
- Ships Same Business Day
- Weight:
- 17.10 LBS
- TYPE:
- ENGINE
- ENGINE TYPE:
- 4-STROKE
- FEATURES:
- STANDARD COMPRESSION PISTON
- PRODUCT NAME:
- REBUILD KIT
- MODEL:
- WRENCH RABBIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$1,132.95Qty in Cart: 0Quantity:Price:$1,132.95Subtotal: -
Wrench Rabbit Complete Engine Rebuild Kit for Kawasaki KX250 2014-2016 WR101-175
WRENCH RABBIT
$1,211.95When your Kawasaki KX250 two-stroke demands a complete overhaul, settling for partial solutions risks reliability and performance. The Wrench Rabbit Complete Engine Rebuild Kit delivers everything...09031308- SKU:
- 09031308
- Availability:
- Ships Same Business Day
- Weight:
- 12.20 LBS
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- ENGINE
- FEATURES:
- STANDARD COMPRESSION PISTON
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- WRENCH RABBIT
- UNITS:
- KIT
$1,211.95Qty in Cart: 0Quantity:Price:$1,211.95Subtotal: -
Wrench Rabbit Complete Engine Rebuild Kit for 2015 Kawasaki KX450F WR101-174
WRENCH RABBIT
$1,211.95When your KX450F engine takes a hit, a quality rebuild kit is the difference between getting back on track quickly and facing weeks of downtime sourcing individual components. The Wrench Rabbit...09031309- SKU:
- 09031309
- Availability:
- Ships Same Business Day
- Weight:
- 16.05 LBS
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- ENGINE
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- WRENCH RABBIT
- RIDING STYLE:
- OFF-ROAD
- FEATURES:
- STANDARD COMPRESSION PISTON
- UNITS:
- KIT
$1,211.95 -
Wrench Rabbit Kawasaki KX85 2014-2025 Complete Engine Rebuild Kit WR101-170
WRENCH RABBIT
$788.95When your Kawasaki KX85 two-stroke demands a full rebuild, you need OEM-quality components that won't compromise performance or reliability. The Wrench Rabbit WR101-170 delivers every critical...09031310- SKU:
- 09031310
- Availability:
- Ships Same Business Day
- Weight:
- 8.05 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
- MODEL:
- WRENCH RABBIT
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- ENGINE
- FEATURES:
- STANDARD COMPRESSION PISTON
$788.95 -
Wrench Rabbit Engine Rebuild Kit for 2013-2015 Suzuki RM-Z250 WR101-169
WRENCH RABBIT
$1,249.95When your RM-Z250's engine shows signs of wear—whether it's loss of compression, bearing play, or general fatigue—a complete rebuild using OEM-quality components is the most cost-effective path to...09031314- SKU:
- 09031314
- Availability:
- Ships Same Business Day
- Weight:
- 12.60 LBS
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- ENGINE
- FEATURES:
- STANDARD COMPRESSION PISTON
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- WRENCH RABBIT
- UNITS:
- KIT
$1,249.95 -
Wrench Rabbit Complete Engine Rebuild Kit Yamaha YZ250F 2014-2015 WR101-168
WRENCH RABBIT
$1,183.95When your Yamaha YZ250F's engine has accumulated hours on the track or trail, a complete rebuild with quality components is the most cost-effective way to restore reliability and performance. The...09031315- SKU:
- 09031315
- Availability:
- Ships Same Business Day
- Weight:
- 12.25 LBS
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- ENGINE
- ENGINE TYPE:
- 4-STROKE
- FEATURES:
- STANDARD COMPRESSION PISTON
- MODEL:
- WRENCH RABBIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$1,183.95Qty in Cart: 0Quantity:Price:$1,183.95Subtotal: -
Wrench Rabbit Engine Rebuild Kit for Kawasaki KX250 1992 WR101-111
WRENCH RABBIT
$867.95When your KX250's engine shows signs of wear, a full rebuild restores performance and reliability without the guesswork of sourcing individual components. The Wrench Rabbit Engine Rebuild Kit for...09031085- SKU:
- 09031085
- Availability:
- Ships Same Business Day
- Weight:
- 14.15 LBS
- MODEL:
- WRENCH RABBIT
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- ENGINE
- ENGINE TYPE:
- 2-STROKE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- FEATURES:
- STANDARD COMPRESSION PISTON
$867.95 -
Wrench Rabbit Complete Engine Rebuild Kit for Kawasaki KX250 2004 WR101-115
WRENCH RABBIT
$895.95A two-stroke engine rebuild demands precision components that work together seamlessly—this kit eliminates the guesswork by bundling OEM-quality parts engineered specifically for your KX250. Whether...09031089- SKU:
- 09031089
- Availability:
- Ships Same Business Day
- Weight:
- 14.40 LBS
- FEATURES:
- STANDARD COMPRESSION PISTON
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 2-STROKE
- MODEL:
- WRENCH RABBIT
- UNITS:
- KIT
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- ENGINE
$895.95Qty in Cart: 0Quantity:Price:$895.95Subtotal: -
WSM Top-End Rebuild Kit - Original Series - Standard 010-827-10
WSM
$241.36A top-end rebuild demands precision components that restore—or exceed—OEM performance standards. The WSM Original Series kit supplies everything needed for a complete piston-to-gasket restoration,...09030123- SKU:
- 09030123
- Availability:
- Ships Same Business Day
- Weight:
- 3.00 LBS
- BORE SIZE METRIC:
- 81.00 MM
- PISTON SIZE METRIC:
- STANDARD
- PRODUCT NAME:
- REBUILD KIT
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- EACH
- MODEL:
- ORIGINAL SERIES
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- TOP END
$241.36Qty in Cart: 0Quantity:Price:$241.36Subtotal: -
XCELDYNE Intake Valve Springs PSIMX2006
XCELDYNE
$75.57If you're serious about extracting maximum horsepower from your engine, valve spring selection is non-negotiable. The XCELDYNE Intake Valve Springs PSIMX2006 deliver measurable performance gains...09261269- SKU:
- 09261269
- Availability:
- Ships Same Business Day
- Weight:
- 0.19 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- VALVE
- APPLICATION:
- INTAKE
- PRODUCT NAME:
- SPRING
- UNITS:
- PAIR
$75.57 -
On Sale
XCELDYNE Exhaust Valve Springs PSIMX2008
XCELDYNE
MSRP: $75.57Now: $48.00Was: $75.57Exhaust valve springs are critical to maintaining consistent valve sealing and preventing float at high RPMs—especially in offroad applications where engine stress and thermal cycling push standard...09261271- SKU:
- 09261271
- Availability:
- Ships Same Business Day
- Weight:
- 0.24 LBS
- MATERIAL:
- TITANIUM
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- SPRING
- TYPE:
- VALVE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- PAIR
MSRP: $75.57Now: $48.00Was: $75.57Qty in Cart: 0Quantity:Price:MSRP: $75.57Now: $48.00Was: $75.57Subtotal: -
XCELDYNE X2 Titanium Valve - Intake X2TIVM42004
XCELDYNE
$110.19Off-road performance demands valves engineered for both maximum flow and maximum durability—the XCELDYNE X2 Titanium Valve delivers both without compromise. Built with a high-flow design and full CrN...09262887- SKU:
- 09262887
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
- MATERIAL:
- TITANIUM
- APPLICATION:
- INTAKE
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- VALVE TRAIN KIT
- UNITS:
- KIT
$110.19
