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 Rotary Valve Gear 010-450
WSM
$45.26If your Sea-Doo's rotary valve isn't operating at peak efficiency, power delivery and throttle response suffer—and so does your watercraft's overall performance. The WSM Rotary Valve Gear 010-450 is...010450- SKU:
- 010450
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- UNITS:
- EACH
- PRODUCT NAME:
- GEAR
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- ROTARY VALVE
$45.26 -
WSM Rotary Valve Shaft 010-455
WSM
$86.94The WSM Rotary Valve Shaft 010-455 is essential for maintaining precise intake timing and fuel delivery in your Sea-Doo engine. A worn or damaged rotary valve shaft compromises performance and can...010455- SKU:
- 010455
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- MATERIAL:
- STEEL
- PRODUCT NAME:
- SHAFT
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- ROTARY VALVE
- UNITS:
- EACH
$86.94 -
WSM Top-End Rebuild Kit - Original Series - Standard 010-802-10
WSM
$247.87A top-end rebuild is essential maintenance for any high-performance engine, and the WSM Original Series kit delivers OEM-quality components at a fraction of full-engine rebuild costs. This...01080210- SKU:
- 01080210
- Availability:
- Ships Same Business Day
- Weight:
- 2.60 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- PRODUCT NAME:
- REBUILD KIT
- UNITS:
- EACH
- BORE SIZE METRIC:
- 77.00 MM
- MODEL:
- ORIGINAL SERIES
- TYPE:
- TOP END
- BORE - OVERSIZE:
- STANDARD
- RIDING STYLE:
- WATERCRAFT
- PISTON MATERIAL:
- ALUMINUM
$247.87 -
WSM Piston Kit - Kawasaki - +.25 mm 010-810-04K
WSM
$86.28When you're pushing your Kawasaki to the limit, stock pistons become your performance ceiling. The WSM Piston Kit delivers OEM-matching quality with critical upgrades—MOS2-coated skirts that actively...01081004- SKU:
- 01081004
- Availability:
- Ships Same Business Day
- Weight:
- 0.81 LBS
- BORE - OVERSIZE:
- +0,25 MM
- BORE - OVERSIZE METRIC:
- +0.25 MM
- BORE SIZE METRIC:
- 76.00 MM
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
$86.28 -
WSM Piston Kit - Kawasaki 650 - +.5 mm 010-810-05K
WSM
$86.28If you're rebuilding or upgrading your Kawasaki 650, piston quality directly impacts combustion efficiency, heat management, and engine longevity. The WSM Piston Kit delivers OEM-equivalent...01081005- SKU:
- 01081005
- Availability:
- Ships Same Business Day
- Weight:
- 0.81 LBS
- BORE - OVERSIZE METRIC:
- +0.50 MM
- RIDING STYLE:
- WATERCRAFT
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- BORE SIZE METRIC:
- 76.00 MM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE:
- +0,50 MM
- UNITS:
- KIT
$86.28 -
WSM Piston Kit - Kawasaki 550 - +.5 mm 010-812-05K
WSM
$81.73If you're building or rebuilding a Kawasaki 550 engine, piston quality directly impacts reliability, power output, and engine longevity. WSM pistons are engineered to OEM or better standards with...01081205- SKU:
- 01081205
- Availability:
- Ships Same Business Day
- Weight:
- 0.70 LBS
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE:
- +0,50 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE SIZE METRIC:
- 75.00 MM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
- MODEL:
- ORIGINAL
$81.73 -
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...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 - .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...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 Piston Kit - Sea-Doo 720 - Standard 010-817K
WSM
$89.33A quality piston kit is the foundation of reliable engine performance, and the WSM 010-817K delivers OEM-equivalent construction with engineered improvements for reduced heat and friction. The MOS2...010817- SKU:
- 010817
- Availability:
- Ships Same Business Day
- Weight:
- 1.13 LBS
- BORE SIZE METRIC:
- 82.00 MM
- PISTON MATERIAL:
- ALUMINUM
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
$89.33 -
WSM Piston Kit - Sea-Doo 720 - +.25 mm 010-817-04K
WSM
$89.33A piston kit failure can sideline your Sea-Doo 720 when you need it most. WSM's +.25 mm oversize pistons deliver OEM-equivalent quality with engineering upgrades specifically designed to reduce...01081704- SKU:
- 01081704
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- BORE - OVERSIZE:
- +0,25 MM
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE METRIC:
- +0.25 MM
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
- BORE SIZE METRIC:
- 82.00 MM
- MODEL:
- ORIGINAL
$89.33 -
WSM Piston Kit - Sea-Doo 800 - Standard 010-818K
WSM
$89.33Sea-Doo 800 engines demand precision-engineered internals to handle sustained high-RPM performance, and OEM pistons often fall short in durability under aggressive use. The WSM Piston Kit delivers...010818- SKU:
- 010818
- Availability:
- Ships Same Business Day
- Weight:
- 1.75 LBS
- BORE SIZE METRIC:
- 82.00 MM
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- WATERCRAFT
$89.33 -
WSM Piston Kit - Sea-Doo 800 - +1 mm 010-818-07K
WSM
$89.33When you're pushing a Sea-Doo 800 to its limits, factory pistons become a liability. The WSM Piston Kit delivers OEM-quality construction with engineered improvements—notably the MOS2 coating that...01081807- SKU:
- 01081807
- Availability:
- Ships Same Business Day
- Weight:
- 1.30 LBS
- BORE - OVERSIZE:
- +1,00 MM
- BORE SIZE METRIC:
- 82.00 MM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE METRIC:
- +1.00 MM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
- MODEL:
- ORIGINAL
$89.33 -
WSM Piston Kit - Sea-Doo 951 - +.25 mm 010-819-04K
WSM
$98.28If you're pushing your Sea-Doo 951 to the limit, factory pistons won't cut it—they'll give up first. This WSM Piston Kit delivers OEM-quality construction with engineering upgrades that reduce heat...01081904- SKU:
- 01081904
- Availability:
- Ships Same Business Day
- Weight:
- 1.50 LBS
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
- BORE - OVERSIZE:
- +0,25 MM
- BORE SIZE METRIC:
- 87.91 MM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE METRIC:
- +0.25 MM
- PRODUCT NAME:
- PISTON KIT
$98.28 -
WSM Piston Kit - Sea-Doo 951 - +.5 mm 010-819-05K
WSM
$98.28If you're rebuilding a Sea-Doo 951 engine or pushing past factory limits, piston quality directly determines whether your engine lives or fails under load. The WSM Piston Kit delivers OEM-equivalent...01081905- SKU:
- 01081905
- Availability:
- Ships Same Business Day
- Weight:
- 0.78 LBS
- BORE - OVERSIZE METRIC:
- +0.50 MM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE:
- +0,50 MM
- UNITS:
- KIT
- BORE SIZE METRIC:
- 87.91 MM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- MODEL:
- ORIGINAL
$98.28 -
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...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 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...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 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...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...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...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 - .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...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
