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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Wrench Rabbit Complete Engine Rebuild Kit for Yamaha YZ250F 2008-2013 WR101-085
WRENCH RABBIT
$1,157.95When your Yamaha YZ250F's engine reaches the end of its service life, a complete rebuild is the most cost-effective way to restore full performance and reliability. This Wrench Rabbit kit eliminates the guesswork by bundling OEM-equivalent components...09031020- SKU:
- 09031020
- Availability:
- Ships Same Business Day
- Weight:
- 13.25 LBS
- FEATURES:
- STANDARD COMPRESSION PISTON
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- ENGINE
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- WRENCH RABBIT
- UNITS:
- KIT
$1,157.95 -
Wrench Rabbit Complete Engine Rebuild Kit Yamaha YZ450F 2003-2005 WR101-086
WRENCH RABBIT
$1,183.95When your Yamaha YZ450F's engine shows signs of wear—whether from race-day abuse or high-mileage riding—a complete rebuild restores factory performance and reliability without the guesswork. The Wrench Rabbit kit consolidates every critical component you...09031021- SKU:
- 09031021
- Availability:
- Ships Same Business Day
- Weight:
- 15.30 LBS
- ENGINE TYPE:
- 4-STROKE
- MODEL:
- WRENCH RABBIT
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- ENGINE
- RIDING STYLE:
- OFF-ROAD
- FEATURES:
- STANDARD COMPRESSION PISTON
- UNITS:
- KIT
$1,183.95 -
Wrench Rabbit Engine Kit Yamaha YZ125 1998-2000 WR101-093
WRENCH RABBIT
$1,211.95A seized or worn two-stroke engine doesn't just cost you track time—it threatens the reliability of your entire bike. The Wrench Rabbit Engine Kit gives you everything needed for a complete, professional-grade rebuild without the hassle of sourcing...09031022- SKU:
- 09031022
- Availability:
- Ships Same Business Day
- Weight:
- 15.75 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- REBUILD KIT
- MODEL:
- WRENCH RABBIT
- TYPE:
- ENGINE
- FEATURES:
- STANDARD COMPRESSION PISTON
$1,211.95 -
Wrench Rabbit Engine Rebuild Kit for Yamaha YZ450F 2010-2013 WR101-088
WRENCH RABBIT
$1,249.95Whether you're recovering from a blown top-end or performing preventative maintenance, the Wrench Rabbit Engine Rebuild Kit gives you everything needed for a complete, professional-grade rebuild of your YZ450F. This kit eliminates the guesswork of...09031023- SKU:
- 09031023
- Availability:
- Ships Same Business Day
- Weight:
- 16.35 LBS
- MODEL:
- WRENCH RABBIT
- TYPE:
- ENGINE
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- REBUILD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- FEATURES:
- STANDARD COMPRESSION PISTON
$1,249.95 -
Wrench Rabbit Yamaha YZ85 2002-2016 Complete Engine Rebuild Kit WR101-089
WRENCH RABBIT
$564.95When a two-stroke engine reaches the end of its service life, a complete rebuild is your most cost-effective path back to peak performance. The Wrench Rabbit YZ85 kit consolidates everything you need—pistons, bearings, gaskets, and seals—into a single,...09031024- SKU:
- 09031024
- Availability:
- Ships Same Business Day
- Weight:
- 8.05 LBS
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 2-STROKE
- MODEL:
- WRENCH RABBIT
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- ENGINE
- FEATURES:
- STANDARD COMPRESSION PISTON
$564.95 -
WSM Crankshaft Assembly 010-1017WSM
WSM
$744.35A crankshaft assembly is the backbone of your engine's power delivery—any imbalance or wear directly compromises efficiency, reliability, and performance. The WSM 010-1017WSM is precision-manufactured to OEM specifications and ready for immediate...09210224- SKU:
- 09210224
- Availability:
- Ships Same Business Day
- Weight:
- 20.95 LBS
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- MATERIAL:
- STEEL
- UNITS:
- KIT
- RIDING STYLE:
- WATERCRAFT
$744.35 -
WSM Crankshaft Assembly 010-1018WSM
WSM
$851.45A reliable crankshaft is the foundation of any solid engine build—it directly impacts power delivery, longevity, and overall drivetrain stability. The WSM 010-1018WSM is engineered to meet or exceed OEM specifications, making it an ideal choice for...09210225- SKU:
- 09210225
- Availability:
- Ships Same Business Day
- Weight:
- 25.20 LBS
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- MATERIAL:
- STEEL
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
$851.45 -
WSM Crankshaft Assembly 010-1019WSM
WSM
$851.45A crankshaft assembly is the heart of your engine's reliability and power delivery—any imbalance or wear translates directly to performance loss and catastrophic failure. The WSM 010-1019WSM is manufactured to OEM specifications and precision-trued to...09210227- SKU:
- 09210227
- Availability:
- Ships Same Business Day
- Weight:
- 27.56 LBS
- MATERIAL:
- STEEL
- RIDING STYLE:
- WATERCRAFT
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- UNITS:
- KIT
$851.45 -
WSM Piston Assembly - Kawasaki 15F - Standard 010-845K
WSM
$98.28A piston assembly is one of the most critical components in your engine—it directly impacts power delivery, thermal management, and long-term reliability. The WSM 15F piston assembly combines OEM-equivalent durability with performance-focused...09101980- SKU:
- 09101980
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE - OVERSIZE:
- STANDARD
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
- BORE SIZE METRIC:
- 83.00 MM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
$98.28 -
WSM Piston Assembly - Yamaha - +.5 mm 010-870-05K
WSM
$111.77When you're pushing your engine to the limit, stock pistons become your weak point. WSM's +.5mm 010 piston assembly delivers OEM-equivalent quality with measurable improvements in heat management and longevity—critical upgrades for sustained high-RPM...09101983- SKU:
- 09101983
- Availability:
- Ships Same Business Day
- Weight:
- 0.46 LBS
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE SIZE METRIC:
- 73.90 MM
- BORE - OVERSIZE:
- +0,50 MM
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
- RIDING STYLE:
- WATERCRAFT
- PRODUCT NAME:
- PISTON KIT
$111.77 -
WSM Piston Assembly - Yamaha - +.25 mm 010-871-04K
WSM
$108.22When you're pushing your engine to its limits, a stock piston assembly becomes your bottleneck. The WSM Piston Assembly delivers OEM-quality construction with thermal management features that reduce friction, lower operating temperatures, and unlock...09101985- SKU:
- 09101985
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- UNITS:
- KIT
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE:
- +0,25 MM
- BORE - OVERSIZE METRIC:
- +0.25 MM
- BORE SIZE METRIC:
- 75.90 MM
- RIDING STYLE:
- WATERCRAFT
$108.22 -
WSM Piston Assembly - Yamaha - Standard 010-872K
WSM
$110.44A piston assembly is the heart of your engine's power delivery, and choosing the right one directly impacts performance, reliability, and longevity. The WSM Piston Assembly for Yamaha engines delivers OEM-quality construction with engineered...09101986- SKU:
- 09101986
- Availability:
- Ships Same Business Day
- Weight:
- 0.71 LBS
- BORE SIZE METRIC:
- 75.90 MM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
$110.44 -
WSM Piston Assembly - Yamaha - +.25 mm 010-872-04K
WSM
$141.11Piston durability and heat management directly impact engine longevity and power output, especially in high-stress racing applications. The WSM +.25mm piston assembly delivers OEM-quality construction with proprietary MOS2 skirt coating that reduces...09101987- SKU:
- 09101987
- Availability:
- Ships Same Business Day
- Weight:
- 0.65 LBS
- BORE - OVERSIZE METRIC:
- +0.25 MM
- PISTON MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
- BORE - OVERSIZE:
- +0,25 MM
- BORE SIZE METRIC:
- 75.90 MM
- MODEL:
- ORIGINAL
$141.11 -
WSM Piston Assembly - Yamaha - +.5 mm 010-872-05K
WSM
$151.13Peak engine performance depends on pistons that can withstand extreme combustion pressures while minimizing friction and heat loss. The WSM +.5mm piston assembly delivers OEM-matching quality with engineering refinements—including a proprietary MOS2...09101988- SKU:
- 09101988
- Availability:
- Ships Same Business Day
- Weight:
- 0.61 LBS
- BORE - OVERSIZE:
- +0,50 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
- BORE SIZE METRIC:
- 75.90 MM
- PRODUCT NAME:
- PISTON KIT
- MODEL:
- ORIGINAL
$151.13 -
WSM Piston Assembly - Sea-Doo - Standard 010-809PK
WSM
$112.59A piston assembly is one of the highest-wear components in your Sea-Doo engine, directly affecting combustion efficiency, power output, and engine longevity. The WSM Standard 010-809PK is engineered to OEM or better specifications with advanced coatings...09101264- SKU:
- 09101264
- Availability:
- Ships Same Business Day
- Weight:
- 1.46 LBS
- BORE SIZE METRIC:
- 87.91 MM
- PISTON MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
- MODEL:
- PLATINUM
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
$112.59 -
WSM Piston Assembly - Sea-Doo - +.5 mm 010-809-05PK
WSM
$112.59A piston assembly is the core of your engine's combustion cycle—it's where power is generated and lost through heat and friction. The WSM +.5mm piston assembly for Sea-Doo jet skis delivers OEM-quality construction with engineered improvements that...09101265- SKU:
- 09101265
- Availability:
- Ships Same Business Day
- Weight:
- 1.49 LBS
- BORE SIZE METRIC:
- 87.91 MM
- MODEL:
- PLATINUM
- PISTON MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE - OVERSIZE:
- +0,50 MM
- UNITS:
- KIT
$112.59 -
WSM Top-End Rebuild Kit - Original Series - .50 mm 010-817-12
WSM
$223.48A top-end rebuild demands precision components that can withstand extreme combustion pressures and maintain clearances across repeated heat cycles. The WSM Original Series kit eliminates guesswork by bundling all necessary internals—pistons, rings, pins,...09030035- SKU:
- 09030035
- Availability:
- Ships Same Business Day
- Weight:
- 3.25 LBS
- PRODUCT NAME:
- REBUILD KIT
- TYPE:
- TOP END
- UNITS:
- EACH
- BORE SIZE METRIC:
- 82.50 MM
- PISTON SIZE METRIC:
- +0.50 MM
- MODEL:
- ORIGINAL SERIES
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
$223.48 -
WSM Top-End Rebuild Kit - Original Series - Standard 010-817-10
WSM
$223.48A top-end rebuild demands precision components that restore your engine's compression, ring seal, and combustion efficiency to factory specifications—or better. The WSM Original Series kit delivers OEM-quality pistons paired with premium gaskets and...09030034- SKU:
- 09030034
- Availability:
- Ships Same Business Day
- Weight:
- 3.20 LBS
- PRODUCT NAME:
- REBUILD KIT
- BORE SIZE METRIC:
- 82.00 MM
- PISTON SIZE METRIC:
- STANDARD
- TYPE:
- TOP END
- UNITS:
- EACH
- MODEL:
- ORIGINAL SERIES
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
$223.48 -
WSM Top-End Rebuild Kit - Platinum Series - .50 mm 010-808-12P
WSM
$250.31A top-end rebuild demands precision components that can withstand extreme combustion pressures and sustained RPM loads. The WSM Platinum Series kit eliminates the guesswork by pairing OEM-quality pistons with premium racing needle bearings and a complete...09030744- SKU:
- 09030744
- Availability:
- Ships Same Business Day
- Weight:
- 3.40 LBS
- PISTON SIZE METRIC:
- +0.50 MM
- PRODUCT NAME:
- REBUILD KIT
- MODEL:
- PLATINUM SERIES
- BORE SIZE METRIC:
- 82.50 MM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- TOP END
- UNITS:
- KIT
$250.31 -
WSM Top-End Rebuild Kit - Platinum Series - 1 mm 010-808-14P
WSM
$250.31A complete top-end rebuild requires precision-matched components that work in concert—mismatched or worn parts will compromise compression, increase blow-by, and kill your power output. The WSM Platinum Series kit eliminates guesswork by pairing...09030745- SKU:
- 09030745
- Availability:
- Ships Same Business Day
- Weight:
- 3.40 LBS
- MODEL:
- PLATINUM SERIES
- PISTON SIZE METRIC:
- +1.00 MM
- TYPE:
- TOP END
- UNITS:
- EACH
- PRODUCT NAME:
- REBUILD KIT
- BORE SIZE METRIC:
- 83.00 MM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
$250.31
