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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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
$232.43 -
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
$232.43 -
WSM Piston Kit - Kawasaki - +.25 mm 010-821-04K
WSM
$89.33When you're pushing your Kawasaki to the limit, stock pistons simply can't keep up with the heat and stress of high-performance riding. The WSM Piston Kit delivers OEM-equivalent quality with engineered upgrades—including a specialized MOS2 coating that...01082104- SKU:
- 01082104
- Availability:
- Ships Same Business Day
- Weight:
- 1.25 LBS
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE METRIC:
- +0.25 MM
- UNITS:
- KIT
- BORE - OVERSIZE:
- +0,25 MM
- BORE SIZE METRIC:
- 80.00 MM
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
$89.33 -
WSM Piston Kit - Kawasaki - +.5 mm 010-821-05K
WSM
$89.33When you're pushing your Kawasaki to the limit, OEM pistons become a liability. The WSM Piston Kit delivers OEM-equivalent quality with meaningful upgrades—particularly the MOS2-coated skirts that actively dissipate heat and reduce friction, translating...01082105- SKU:
- 01082105
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- PRODUCT NAME:
- PISTON KIT
- BORE SIZE METRIC:
- 80.00 MM
- MODEL:
- ORIGINAL
- BORE - OVERSIZE:
- +0,50 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
$89.33 -
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
$241.36 -
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
$357.62 -
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 Piston Kit - Yamaha 701- +.25 mm 010-825-04K
WSM
$89.33Stock pistons wear out, overheat, and limit your engine's potential—especially under sustained high-RPM operation. The WSM Piston Kit delivers OEM-equivalent quality with critical performance upgrades: MOS2-coated skirts that actively dissipate heat...01082504- SKU:
- 01082504
- Availability:
- Ships Same Business Day
- Weight:
- 1.05 LBS
- BORE - OVERSIZE:
- +0,25 MM
- RIDING STYLE:
- WATERCRAFT
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
- BORE - OVERSIZE METRIC:
- +0.25 MM
- BORE SIZE METRIC:
- 81.00 MM
- PRODUCT NAME:
- PISTON KIT
$89.33 -
WSM Piston Kit - Yamaha 701 - +.5 mm 010-825-05K
WSM
$89.33When you're pushing a Yamaha 701 to its limits, factory pistons become your weakest link. The WSM Piston Kit delivers OEM-quality construction with critical upgrades—MOS2-coated skirts that actively dissipate heat, specially hardened ring grooves, and an...01082505- SKU:
- 01082505
- Availability:
- Ships Same Business Day
- Weight:
- 1.20 LBS
- BORE SIZE METRIC:
- 81.00 MM
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE:
- +0,50 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- UNITS:
- KIT
$89.33 -
WSM Piston Kit - +.75 mm - Yamaha 701 010-825-06K
WSM
$89.33When you're pushing your Yamaha 701 to the limit, stock pistons become your performance ceiling. This WSM kit delivers the displacement increase and thermal management you need to unlock more power while maintaining the reliability that keeps you on the...01082506- SKU:
- 01082506
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- BORE - OVERSIZE METRIC:
- +0.75 MM
- PRODUCT NAME:
- PISTON KIT
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
- BORE - OVERSIZE:
- +0,75 MM
- BORE SIZE METRIC:
- 81.00 MM
- RIDING STYLE:
- WATERCRAFT
- MODEL:
- ORIGINAL
$89.33 -
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 -
WSM Top-End Rebuild Kit - Original Series - .50 mm 010-826-12
WSM
$250.31A top-end rebuild demands precision components that restore your engine to factory specifications—or beyond. The WSM Original Series kit eliminates the guesswork by bundling every critical component you need for a complete piston and gasket overhaul in...01082612- SKU:
- 01082612
- Availability:
- Ships Same Business Day
- Weight:
- 3.15 LBS
- BORE SIZE METRIC:
- 84.50 MM
- PRODUCT NAME:
- REBUILD KIT
- BORE - OVERSIZE:
- +0,50 MM
- MODEL:
- ORIGINAL SERIES
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE METRIC:
- +0.50 MM
- TYPE:
- TOP END
- UNITS:
- EACH
$250.31 -
WSM Top-End Rebuild Kit - Original Series - .50 mm 010-826-22
WSM
$393.39A top-end rebuild is essential maintenance for any high-performance engine—whether you're preparing for race season or restoring peak power after extended use. The WSM Original Series kit delivers OEM-quality components engineered to tight tolerances,...01082622- SKU:
- 01082622
- Availability:
- Ships Same Business Day
- Weight:
- 5.20 LBS
- BORE SIZE METRIC:
- 84.50 MM
- BORE - OVERSIZE:
- +0,50 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- TYPE:
- TOP END
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- EACH
- MODEL:
- ORIGINAL SERIES
- PRODUCT NAME:
- REBUILD KIT
- RIDING STYLE:
- WATERCRAFT
$393.39 -
WSM Piston Kit - Yamaha - +.5 mm 010-829-05PK
WSM
$98.28When you're pushing your Yamaha engine to the limit, stock pistons become your performance ceiling. The WSM Piston Kit delivers OEM-matching quality with critical upgrades—superior ring design, thermal management coatings, and hardened ring grooves—that...01082905P- SKU:
- 01082905P
- Availability:
- Ships Same Business Day
- Weight:
- 1.32 LBS
- BORE - OVERSIZE METRIC:
- +0.50 MM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- +0,50 MM
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
- BORE SIZE METRIC:
- 80.00 MM
- MODEL:
- PLATINUM
- PRODUCT NAME:
- PISTON KIT
$98.28 -
WSM Top-End Rebuild Kit - Platinum Series - Standard 010-829-10P
WSM
$447.05A top-end rebuild demands precision components that can handle sustained high-RPM loads without compromise. The WSM Platinum Series kit delivers OEM-quality pistons, rings, and bearings in a complete package, eliminating the guesswork of sourcing...01082910BP- SKU:
- 01082910BP
- Availability:
- Ships Same Business Day
- Weight:
- 5.55 LBS
- PISTON MATERIAL:
- ALUMINUM
- TYPE:
- TOP END
- PRODUCT NAME:
- REBUILD KIT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 79.90 MM
- MODEL:
- PLATINUM SERIES
- UNITS:
- EACH
- RIDING STYLE:
- WATERCRAFT
$447.05 -
WSM Piston Kit - GP1200R - Standard 010-829PK
WSM
$98.28When you're running a GP1200R at the limit, stock pistons become a reliability liability. The WSM Piston Kit delivers OEM-equivalent quality with engineered improvements—specifically the MOS2 coating that actively dissipates heat and reduces friction,...010829BP- SKU:
- 010829BP
- Availability:
- Ships Same Business Day
- Weight:
- 1.32 LBS
- BORE SIZE METRIC:
- 80.00 MM
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
- MODEL:
- PLATINUM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
$98.28 -
WSM Piston Kit - Polaris 750 - Standard 010-830K
WSM
$89.33When you're pushing a Polaris 750 to its limits, factory pistons can't keep pace with the heat and stress your engine generates. The WSM Piston Kit delivers OEM-equivalent quality with critical upgrades—MOS2-coated skirts that actively dissipate heat...010830- SKU:
- 010830
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 69.75 MM
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
- RIDING STYLE:
- WATERCRAFT
- PISTON MATERIAL:
- ALUMINUM
$89.33 -
WSM Piston Kit - Polaris 750 - +.5 mm 010-830-05K
WSM
$89.33If you're pushing your Polaris 750 to the limit, factory pistons won't cut it—especially at higher boost levels or sustained RPMs. The WSM +.5mm piston kit delivers OEM-matched quality with critical upgrades: a MOS2-coated skirt that actively dissipates...01083005- SKU:
- 01083005
- Availability:
- Ships Same Business Day
- Weight:
- 0.65 LBS
- RIDING STYLE:
- WATERCRAFT
- BORE SIZE METRIC:
- 69.75 MM
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE:
- +0,50 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- UNITS:
- KIT
$89.33
