Dirt Bike Engine Rebuild Kits
Dirt Bike Engine Rebuild Kits for Kawasaki KX100, KTM XC-W 250 & Honda CRF250R at JJ Motorsports
Revive your dirt bike's engine to factory-fresh performance with premium rebuild kits from JJ Motorsports, featuring forged pistons, crankshafts, bearings, seals, and gaskets for superior compression, reduced vibration, and long-term reliability in motocross, enduro, and trail riding. Our selection includes complete top- and bottom-end kits designed for precise fitment, optimal oil flow, and enhanced power delivery without custom machining. Compatible with popular models like Kawasaki KX100, KTM XC/XC-W 250, Husqvarna TE250, and Honda CRF250R, these high-quality components from trusted brands ensure leak-free assembly, better heat management, and race-ready durability in dusty, high-RPM conditions. From Wiseco's comprehensive KX100 kits with hour meters to Vertex's all-in-one KTM rebuilds and Athena's high-performance CRF pistons, get everything needed for a pro-level refresh—pistons, rings, bearings, and gaskets—to restore throttle snap, efficiency, and confidence on every rip.
Shop brands like Wiseco, Vertex, and Athena for race-proven quality. Explore related categories such as dirt bike piston and ring kits for top-end focus or dirt bike engine for cylinders and valves.
Top Dirt Bike Engine Rebuild Kits
- Wiseco Engine Rebuild Kit 52.50 mm Kawasaki KX100 1995-2013 PWR173-100 – Comprehensive top- and bottom-end kit with high-quality crankshaft, rod assembly, main bearings, seals, gaskets, and hour meter bracket for Kawasaki KX100 models; ensures optimal performance and easy maintenance.
- VERTEX Engine Rebuild Kit - KTM XC/XC-W 250 | Husqvarna TE250 WR101-091 – All-in-one rebuild kit with Vertex piston, Hot Rods crankshaft, bearings/seals, transmission kit, and complete gaskets; perfect for professional top- and bottom-end refresh on KTM and Husqvarna 250cc models.
- ATHENA Piston Kit with Gaskets - 76.76 mm - CRF250R P5F0768245003B – High-performance 76.76 mm forged aluminum piston kit with rings, gaskets, and coatings for reduced friction; engineered for Honda CRF250R 4-stroke off-road with superior airflow and longevity.
Browse our in-stock inventory below with same-day shipping and expert support. Free shipping on orders over $99! Questions? Contact us for fitment advice!
- Product
- Qty in Cart
- Quantity
- Price
- Subtotal
-
WSM Top-End Rebuild Kit - Original Series - .50 mm 010-802-12
WSM
$247.87A top-end rebuild is fundamental to restoring your engine's compression, reliability, and power output—and the WSM Original Series kit gives you everything needed in one complete package. Whether you're refreshing a high-mileage engine or preparing for...01080212- SKU:
- 01080212
- Availability:
- Ships Same Business Day
- Weight:
- 2.85 LBS
- BORE SIZE METRIC:
- 77.50 MM
- PRODUCT NAME:
- REBUILD KIT
- BORE - OVERSIZE:
- +0,50 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- MODEL:
- ORIGINAL SERIES
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- TOP END
- UNITS:
- EACH
$247.87Qty in Cart: 0Quantity:Price:$247.87Subtotal: -
WSM Top-End Rebuild Kit - Original Series - Standard 010-810-10
WSM
$252.25A top-end rebuild demands precision components that restore your engine to factory specifications or better. The WSM Top-End Rebuild Kit eliminates the guesswork of sourcing individual gaskets, rings, and bearings by bundling everything you need in one...01081010- SKU:
- 01081010
- Availability:
- Ships Same Business Day
- Weight:
- 2.55 LBS
- MODEL:
- ORIGINAL SERIES
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 76.00 MM
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- TOP END
- UNITS:
- EACH
$252.25 -
WSM Top-End Rebuild Kit - Original Series - 1 mm 010-810-14
WSM
$252.25A complete top-end rebuild requires precision-matched components that work as an integrated system—not mismatched parts cobbled together. The WSM Original Series kit eliminates guesswork by pairing OEM-quality pistons, rings, and bearings with all...01081014- SKU:
- 01081014
- Availability:
- Ships Same Business Day
- Weight:
- 2.65 LBS
- TYPE:
- TOP END
- UNITS:
- EACH
- BORE - OVERSIZE:
- +1,00 MM
- BORE SIZE METRIC:
- 77.00 MM
- BORE - OVERSIZE METRIC:
- +1.00 MM
- PISTON MATERIAL:
- ALUMINUM
- MODEL:
- ORIGINAL SERIES
- PRODUCT NAME:
- REBUILD KIT
- RIDING STYLE:
- WATERCRAFT
$252.25Qty in Cart: 0Quantity:Price:$252.25Subtotal: -
WSM Top-End Rebuild Kit - Original Series - Standard 010-812-10
WSM
$205.60A top-end rebuild is essential when your engine shows signs of wear—loss of compression, increased blow-by, or declining power output. The WSM Top-End Rebuild Kit delivers OEM-quality components engineered to restore your engine to factory specifications...01081210- SKU:
- 01081210
- Availability:
- Ships Same Business Day
- Weight:
- 2.45 LBS
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE - OVERSIZE:
- STANDARD
- BORE SIZE METRIC:
- 75.00 MM
- UNITS:
- EACH
- MODEL:
- ORIGINAL SERIES
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- TOP END
$205.60 -
WSM Top-End Rebuild Kit - Original Series - Standard 010-816-10
WSM
$223.48A top-end rebuild is essential when your engine shows signs of wear—loss of compression, increased blow-by, or declining power output. The WSM Top-End Rebuild Kit delivers OEM-quality components engineered to restore your engine to factory specifications...01081610- SKU:
- 01081610
- Availability:
- Ships Same Business Day
- Weight:
- 2.88 LBS
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- PRODUCT NAME:
- REBUILD KIT
- MODEL:
- ORIGINAL SERIES
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- TOP END
- UNITS:
- EACH
- BORE SIZE METRIC:
- 78.00 MM
$223.48 -
WSM Top-End Rebuild Kit - Original Series - .50 mm 010-816-12
WSM
$223.48A top-end rebuild demands precision components that can withstand extreme combustion pressures and sustained high RPM operation. The WSM Original Series Kit delivers factory-quality pistons paired with complete gasket and bearing assemblies, eliminating...01081612- SKU:
- 01081612
- Availability:
- Ships Same Business Day
- Weight:
- 2.90 LBS
- PRODUCT NAME:
- REBUILD KIT
- UNITS:
- EACH
- MODEL:
- ORIGINAL SERIES
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE SIZE METRIC:
- 78.50 MM
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- TOP END
- BORE - OVERSIZE:
- +0,50 MM
- PISTON MATERIAL:
- ALUMINUM
$223.48 -
WSM Top-End Rebuild Kit - Original Series - Standard 010-818-10
WSM
$223.48A complete top-end rebuild demands precision components that maintain tight tolerances under extreme combustion pressures. The WSM Top-End Rebuild Kit delivers OEM-quality pistons, rings, and bearings in one package, eliminating the guesswork of sourcing...01081810- SKU:
- 01081810
- Availability:
- Ships Same Business Day
- Weight:
- 3.15 LBS
- MODEL:
- ORIGINAL SERIES
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- PRODUCT NAME:
- REBUILD KIT
- UNITS:
- EACH
- BORE SIZE METRIC:
- 82.00 MM
- TYPE:
- TOP END
$223.48 -
WSM Top-End Rebuild Kit - Original Series - .50 mm 010-818-12
WSM
$223.48A top-end rebuild is critical maintenance for high-performance engines, and this WSM kit delivers OEM-quality components in one complete package. Rather than sourcing pistons, rings, and gaskets separately, you get a proven combination engineered to work...01081812- SKU:
- 01081812
- Availability:
- Ships Same Business Day
- Weight:
- 3.45 LBS
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE SIZE METRIC:
- 82.50 MM
- TYPE:
- TOP END
- UNITS:
- EACH
- BORE - OVERSIZE:
- +0,50 MM
- PISTON MATERIAL:
- ALUMINUM
- MODEL:
- ORIGINAL SERIES
- PRODUCT NAME:
- REBUILD KIT
- RIDING STYLE:
- WATERCRAFT
$223.48 -
WSM Top-End Rebuild Kit - Original Series - 1 mm 010-818-14
WSM
$223.48A top-end rebuild is non-negotiable when you're chasing peak performance and reliability. The WSM Original Series kit delivers OEM-quality pistons, rings, and bearings in one complete package, eliminating the guesswork of sourcing individual components...01081814- SKU:
- 01081814
- Availability:
- Ships Same Business Day
- Weight:
- 3.40 LBS
- BORE - OVERSIZE:
- +1,00 MM
- BORE SIZE METRIC:
- 83.00 MM
- TYPE:
- TOP END
- BORE - OVERSIZE METRIC:
- +1.00 MM
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- EACH
- MODEL:
- ORIGINAL SERIES
- PRODUCT NAME:
- REBUILD KIT
- RIDING STYLE:
- WATERCRAFT
$223.48Qty in Cart: 0Quantity:Price:$223.48Subtotal: -
WSM Top-End Rebuild Kit - Original Series - Standard 010-819-10
WSM
$330.79A top-end rebuild is the most direct path to restoring lost compression, sealing blow-by, and recovering horsepower in a worn engine. The WSM Original Series kit eliminates the guesswork by bundling every critical component you need—pistons, rings, and...01081910- SKU:
- 01081910
- Availability:
- Ships Same Business Day
- Weight:
- 4.05 LBS
- BORE - OVERSIZE:
- STANDARD
- TYPE:
- TOP END
- UNITS:
- EACH
- BORE SIZE METRIC:
- 87.91 MM
- MODEL:
- ORIGINAL SERIES
- PRODUCT NAME:
- REBUILD KIT
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON MATERIAL:
- ALUMINUM
$330.79 -
WSM Top-End Rebuild Kit - Original Series - .25 mm 010-819-11
WSM
$330.79A top-end rebuild is essential when your piston rings lose compression or your engine shows signs of blow-by—and this WSM kit delivers everything needed in one complete package. Factory OEM quality components paired with racing-grade needle bearings...01081911- SKU:
- 01081911
- Availability:
- Ships Same Business Day
- Weight:
- 4.15 LBS
- MODEL:
- ORIGINAL SERIES
- PRODUCT NAME:
- REBUILD KIT
- UNITS:
- EACH
- BORE - OVERSIZE METRIC:
- +0.25 MM
- BORE SIZE METRIC:
- 88.16 MM
- PISTON MATERIAL:
- ALUMINUM
- BORE - OVERSIZE:
- +0,25 MM
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- TOP END
$330.79Qty in Cart: 0Quantity:Price:$330.79Subtotal: -
WSM Top-End Rebuild Kit - Original Series - .50 mm 010-819-12
WSM
$330.79A top-end rebuild demands precision components that restore your engine to OEM specifications or better. The WSM Original Series kit supplies race-grade pistons, rings, and bearings in one complete package, eliminating the guesswork of sourcing...01081912- SKU:
- 01081912
- Availability:
- Ships Same Business Day
- Weight:
- 4.20 LBS
- MODEL:
- ORIGINAL SERIES
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- PRODUCT NAME:
- REBUILD KIT
- BORE - OVERSIZE METRIC:
- +0.50 MM
- TYPE:
- TOP END
- UNITS:
- EACH
- BORE - OVERSIZE:
- +0,50 MM
- BORE SIZE METRIC:
- 88.41 MM
$330.79 -
WSM Top-End Rebuild Kit - Original Series - .50 mm 010-820-12
WSM
$232.43A complete top-end rebuild demands precision-matched components that work as an integrated system—not a collection of individual parts. The WSM Original Series kit eliminates guesswork by pairing racing-grade pistons with corresponding rings, pins, and...01082012- SKU:
- 01082012
- Availability:
- Ships Same Business Day
- Weight:
- 2.95 LBS
- BORE - OVERSIZE:
- +0,50 MM
- MODEL:
- ORIGINAL SERIES
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- TOP END
- UNITS:
- EACH
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE SIZE METRIC:
- 80.50 MM
- PRODUCT NAME:
- REBUILD KIT
$232.43Qty in Cart: 0Quantity:Price:$232.43Subtotal: -
WSM Top-End Rebuild Kit - Original Series - .75 mm 010-820-13
WSM
$232.43A complete top-end rebuild demands precision-matched components that work in concert—and this WSM Original Series kit eliminates guesswork by pairing race-spec pistons with properly sized rings, pins, and clips engineered for your displacement. Whether...01082013- SKU:
- 01082013
- Availability:
- Ships Same Business Day
- Weight:
- 2.95 LBS
- BORE - OVERSIZE:
- +0,75 MM
- BORE - OVERSIZE METRIC:
- +0.75 MM
- TYPE:
- TOP END
- BORE SIZE METRIC:
- 80.75 MM
- MODEL:
- ORIGINAL SERIES
- PRODUCT NAME:
- REBUILD KIT
- RIDING STYLE:
- WATERCRAFT
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- EACH
$232.43Qty in Cart: 0Quantity:Price:$232.43Subtotal: -
WSM Top-End Rebuild Kit - Original Series - Standard 010-821-10
WSM
$223.48A top-end rebuild is non-negotiable for maintaining peak cylinder performance and extending engine life. This WSM Original Series kit delivers OEM-quality components in one complete package, eliminating the guesswork of sourcing individual gaskets and...01082110- SKU:
- 01082110
- Availability:
- Ships Same Business Day
- Weight:
- 2.95 LBS
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 80.00 MM
- PRODUCT NAME:
- REBUILD KIT
- MODEL:
- ORIGINAL SERIES
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- TOP END
- UNITS:
- EACH
$223.48Qty in Cart: 0Quantity:Price:$223.48Subtotal: -
WSM Top-End Rebuild Kit - Original Series - .25 mm 010-821-11
WSM
$241.36A top-end rebuild is critical to maintaining peak combustion efficiency and cylinder pressure, especially if you're running extended track sessions or pushing higher RPMs. This WSM Original Series kit delivers OEM-quality components in one complete...01082111- SKU:
- 01082111
- Availability:
- Ships Same Business Day
- Weight:
- 3.40 LBS
- BORE - OVERSIZE:
- +0,25 MM
- PRODUCT NAME:
- REBUILD KIT
- BORE SIZE METRIC:
- 80.25 MM
- MODEL:
- ORIGINAL SERIES
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- TOP END
- UNITS:
- EACH
- BORE - OVERSIZE METRIC:
- +0.25 MM
$241.36 -
WSM Top-End Rebuild Kit - Original Series - .50 mm 010-821-12
WSM
$241.36A top-end rebuild demands precision components that withstand extreme combustion pressures and sustained RPM loads. The WSM Original Series kit delivers OEM-quality pistons, rings, and bearings in one complete package, eliminating the guesswork of...01082112- SKU:
- 01082112
- Availability:
- Ships Same Business Day
- Weight:
- 3.40 LBS
- BORE SIZE METRIC:
- 80.50 MM
- PRODUCT NAME:
- REBUILD KIT
- UNITS:
- EACH
- BORE - OVERSIZE METRIC:
- +0.50 MM
- MODEL:
- ORIGINAL SERIES
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- +0,50 MM
- PISTON MATERIAL:
- ALUMINUM
- TYPE:
- TOP END
$241.36Qty in Cart: 0Quantity:Price:$241.36Subtotal: -
WSM Top-End Rebuild Kit - Original Series - Standard 010-821-20
WSM
$357.62When your engine's internals show wear, a quality top-end rebuild kit is the most cost-effective path to restoring power and reliability without a complete engine overhaul. The WSM Original Series delivers OEM-grade components that work together as a...01082120- SKU:
- 01082120
- Availability:
- Ships Same Business Day
- Weight:
- 4.50 LBS
- TYPE:
- TOP END
- UNITS:
- EACH
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON MATERIAL:
- ALUMINUM
- BORE SIZE METRIC:
- 80.00 MM
- MODEL:
- ORIGINAL SERIES
- PRODUCT NAME:
- REBUILD KIT
- RIDING STYLE:
- WATERCRAFT
$357.62Qty in Cart: 0Quantity:Price:$357.62Subtotal: -
WSM Top-End Rebuild Kit - Original Series - .50 mm 010-821-22
WSM
$357.62A top-end rebuild demands precision components that can withstand extreme combustion pressures and sustained high RPMs—this kit delivers exactly that. The WSM Original Series combines OEM-quality pistons with premium supporting hardware, eliminating the...01082122- SKU:
- 01082122
- Availability:
- Ships Same Business Day
- Weight:
- 4.85 LBS
- BORE SIZE METRIC:
- 80.50 MM
- PRODUCT NAME:
- REBUILD KIT
- UNITS:
- EACH
- BORE - OVERSIZE METRIC:
- +0.50 MM
- MODEL:
- ORIGINAL SERIES
- BORE - OVERSIZE:
- +0,50 MM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- TOP END
$357.62 -
WSM Top-End Rebuild Kit - Original Series - Standard 010-825-10
WSM
$250.31A top-end rebuild demands precision components that restore your engine to factory specifications—or exceed them. The WSM Top-End Rebuild Kit delivers OEM-quality pistons, rings, and gaskets in one complete package, eliminating the guesswork and multiple...01082510- SKU:
- 01082510
- Availability:
- Ships Same Business Day
- Weight:
- 2.95 LBS
- MODEL:
- ORIGINAL SERIES
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- PRODUCT NAME:
- REBUILD KIT
- BORE SIZE METRIC:
- 81.00 MM
- TYPE:
- TOP END
- UNITS:
- EACH
$250.31
