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 - .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 -
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...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 - 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...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...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 Top-End Rebuild Kit - Original Series - Standard 010-831-10
WSM
$352.08A complete top-end rebuild requires precision-matched components that work in harmony—mismatched or worn parts will compromise ring seal, increase blowby, and tank your power output. The WSM Top-End...01083110- SKU:
- 01083110
- Availability:
- Ships Same Business Day
- Weight:
- 3.20 LBS
- PRODUCT NAME:
- REBUILD KIT
- UNITS:
- EACH
- BORE SIZE METRIC:
- 65.00 MM
- TYPE:
- TOP END
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON MATERIAL:
- ALUMINUM
- MODEL:
- ORIGINAL SERIES
- RIDING STYLE:
- WATERCRAFT
$352.08 -
WSM Top-End Rebuild Kit - Original Series - .50 mm 010-832-22
WSM
$326.90A complete top-end rebuild demands precision components that restore your engine to factory specifications or beyond. The WSM Original Series kit delivers OEM-quality pistons, rings, and gaskets in...01083222- SKU:
- 01083222
- Availability:
- Ships Same Business Day
- Weight:
- 4.13 LBS
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- TOP END
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- EACH
- BORE SIZE METRIC:
- 81.50 MM
- MODEL:
- ORIGINAL SERIES
- PISTON SIZE METRIC:
- +0.50 MM
- RIDING STYLE:
- WATERCRAFT
$326.90 -
WSM Motor Mount - K440/550 011-104
WSM
$58.37Worn or broken motor mounts compromise engine stability, increase vibration transfer to the chassis, and can accelerate damage to surrounding components. A quality replacement mount restores proper...011104- SKU:
- 011104
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- TYPE:
- ENGINE
- RIDING STYLE:
- WATERCRAFT
- PRODUCT NAME:
- MOUNT
- UNITS:
- EACH
$58.37 -
WSM Motor Mount - K650/750 011-105
WSM
$58.37Worn or cracked motor mounts compromise engine stability, increase vibration transfer to the chassis, and can accelerate damage to surrounding components. The WSM Motor Mount restores proper engine...011105- SKU:
- 011105
- Availability:
- Ships Same Business Day
- Weight:
- 0.38 LBS
- TYPE:
- ENGINE
- PRODUCT NAME:
- MOUNT
- UNITS:
- EACH
- RIDING STYLE:
- WATERCRAFT
$58.37 -
WSM Motor Mount - S580/720 011-107
WSM
$58.37Worn or cracked motor mounts compromise engine stability, increase vibration transfer to the chassis, and can accelerate damage to surrounding components. The WSM Motor Mount (011-107) restores...011107- SKU:
- 011107
- Availability:
- Ships Same Business Day
- Weight:
- 0.32 LBS
- PRODUCT NAME:
- MOUNT
- TYPE:
- ENGINE
- UNITS:
- EACH
- RIDING STYLE:
- WATERCRAFT
$58.37 -
WSM Motor Mount - S800 FRT 011-108
WSM
$75.07Worn or cracked motor mounts compromise engine stability, increase vibration transfer to the chassis, and can lead to costly drivetrain damage if left unaddressed. The WSM Motor Mount S800 FRT...011108- SKU:
- 011108
- Availability:
- Ships Same Business Day
- Weight:
- 0.76 LBS
- RIDING STYLE:
- WATERCRAFT
- PRODUCT NAME:
- MOUNT
- UNITS:
- EACH
- TYPE:
- ENGINE
$75.07 -
WSM Motor Mount - Y650/701 SJ 011-115
WSM
$58.37Worn or broken motor mounts compromise engine stability, increase vibration transfer to the chassis, and can lead to misalignment issues that affect handling and drivetrain longevity. The WSM Motor...011115- SKU:
- 011115
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
- TYPE:
- ENGINE
- PRODUCT NAME:
- MOUNT
- UNITS:
- EACH
- RIDING STYLE:
- WATERCRAFT
$58.37 -
WSM Motor Mount - Y701/760 011-116
WSM
$66.72Worn or broken motor mounts compromise engine stability, transmit excessive vibration into the cabin, and can lead to misalignment of engine accessory belts and hoses. A quality replacement mount...011116- SKU:
- 011116
- Availability:
- Ships Same Business Day
- Weight:
- 0.44 LBS
- RIDING STYLE:
- WATERCRAFT
- PRODUCT NAME:
- MOUNT
- UNITS:
- EACH
- TYPE:
- ENGINE
$66.72 -
WSM Motor Mount - Y500/650/701 011-117
WSM
$66.72Worn or broken motor mounts compromise engine stability, increase vibration transfer to the chassis, and can accelerate damage to surrounding components. The WSM Motor Mount restores proper engine...011117- SKU:
- 011117
- Availability:
- Ships Same Business Day
- Weight:
- 0.56 LBS
- PRODUCT NAME:
- MOUNT
- TYPE:
- ENGINE
- UNITS:
- EACH
- RIDING STYLE:
- WATERCRAFT
$66.72 -
WSM Motor Mount - GP1200R 011-126
WSM
$83.42Motor mounts are critical chassis components that isolate engine vibration and maintain proper engine geometry under load. Worn or damaged OEM mounts allow excessive movement, leading to driveline...011126- SKU:
- 011126
- Availability:
- Ships Same Business Day
- Weight:
- 0.76 LBS
- TYPE:
- ENGINE
- RIDING STYLE:
- WATERCRAFT
- PRODUCT NAME:
- MOUNT
- UNITS:
- EACH
$83.42 -
WSM Crank Case Block Off Plate 011-208
WSM
$14.36A crank case block off plate is essential for any forced induction setup, preventing unwanted blow-by gases from escaping and maintaining proper crankcase pressure. The WSM 011-208 delivers the...011208- SKU:
- 011208
- Availability:
- Ships Same Business Day
- Weight:
- 0.14 LBS
- RIDING STYLE:
- WATERCRAFT
- PRODUCT NAME:
- ELIMINATION KIT
- TYPE:
- OIL INJECTION
- COLOR/FINISH:
- BLACK
- MATERIAL:
- BILLET ALUMINUM
- UNITS:
- KIT
- BASE COLOR:
- BLACK
$14.36 -
WSM Crank Case Block Off Plate 011-212
WSM
$14.36A crankcase block off plate eliminates vacuum leaks and prevents oil vapor from escaping your engine's crankcase ventilation system, directly improving combustion efficiency and reducing unwanted...011212- SKU:
- 011212
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- MATERIAL:
- BILLET ALUMINUM
- PRODUCT NAME:
- ELIMINATION KIT
- TYPE:
- OIL INJECTION
- BASE COLOR:
- BLACK
- RIDING STYLE:
- WATERCRAFT
- COLOR/FINISH:
- BLACK
- UNITS:
- KIT
$14.36
