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 Piston Kit - Kawasaki - Standard 010-821K
WSM
$85.08When you're pushing your Kawasaki to the limit, stock pistons become your weak point. The WSM Piston Kit delivers OEM-equivalent quality with engineering upgrades that reduce friction, manage heat...010821- SKU:
- 010821
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- PISTON MATERIAL:
- ALUMINUM
- BORE SIZE METRIC:
- 80.00 MM
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- MODEL:
- ORIGINAL
$85.08Qty in Cart: 0Quantity:Price:$85.08Subtotal: -
WSM Top-End Rebuild Kit - Original Series - .50 mm 010-825-12
WSM
$238.39When your top-end is worn, performance suffers and reliability becomes questionable. The WSM Top-End Rebuild Kit delivers OEM-quality components engineered to restore compression, seal integrity, and...01082512- SKU:
- 01082512
- Availability:
- Ships Same Business Day
- Weight:
- 2.90 LBS
- PRODUCT NAME:
- REBUILD KIT
- UNITS:
- EACH
- MODEL:
- ORIGINAL SERIES
- BORE - OVERSIZE METRIC:
- +0.50 MM
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- TOP END
- BORE - OVERSIZE:
- +0,50 MM
- BORE SIZE METRIC:
- 81.50 MM
- PISTON MATERIAL:
- ALUMINUM
$238.39Qty in Cart: 0Quantity:Price:$238.39Subtotal: -
WSM Piston Kit - Polaris - Standard 010-832K
WSM
$93.60If you're running Polaris sleds hard, your stock pistons are likely your weakest link—heat and friction rob horsepower and shorten engine life. The WSM Piston Kit replaces worn or damaged pistons...010832- SKU:
- 010832
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- UNITS:
- KIT
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- STANDARD
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- BORE SIZE METRIC:
- 81.00 MM
- PRODUCT NAME:
- PISTON KIT
$93.60Qty in Cart: 0Quantity:Price:$93.60Subtotal: -
WSM Top-End Rebuild Kit - Original Series - Standard 010-832-10
WSM
$229.87A worn top-end compromises horsepower, fuel efficiency, and engine reliability. The WSM Top-End Rebuild Kit gives you OEM-grade components engineered to restore or exceed original performance...01083210- SKU:
- 01083210
- Availability:
- Ships Same Business Day
- Weight:
- 2.95 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- PRODUCT NAME:
- REBUILD KIT
- UNITS:
- EACH
- MODEL:
- ORIGINAL SERIES
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- TOP END
- BORE - OVERSIZE:
- STANDARD
- BORE SIZE METRIC:
- 81.00 MM
$229.87Qty in Cart: 0Quantity:Price:$229.87Subtotal: -
WSM Motor Mount - S800 RR 011-109
WSM
$43.49Worn or broken motor mounts compromise engine stability, increase vibration transfer to the chassis, and can lead to costly drivetrain damage over time. The WSM Motor Mount for the S800 RR restores...011109- SKU:
- 011109
- Availability:
- Ships Same Business Day
- Weight:
- 0.63 LBS
- RIDING STYLE:
- WATERCRAFT
- PRODUCT NAME:
- MOUNT
- UNITS:
- EACH
- TYPE:
- ENGINE
$43.49Qty in Cart: 0Quantity:Price:$43.49Subtotal: -
MOOSE RACING Valve Shim - 7.48 x 1.65 - 5 pack MSE5PK748165
MOOSE RACING
$10.95Precision valve shim sets are essential for maintaining proper valve clearance and preventing costly valve train damage during high-performance operation. These MOOSE RACING shims eliminate guesswork...09261867- SKU:
- 09261867
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- SNOW
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
- OUTSIDE DIAMETER METRIC:
- 7.48 MM
- RIDING STYLE:
- ATV
- VALVE SHIM THICKNESS METRIC:
- 1.65 MM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
$10.95 -
MOOSE RACING Valve Shim - 8.90 x 2.16 - 5 pack MSE5PK890216
MOOSE RACING
$10.95Proper valve shim selection is critical for maintaining correct valve clearance and preventing costly engine damage. These forged 4140 steel shims are engineered for precision and durability, making...09261916- SKU:
- 09261916
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- VALVE SHIM THICKNESS METRIC:
- 2.16 MM
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- ATV
$10.95Qty in Cart: 0Quantity:Price:$10.95Subtotal: -
MOOSE RACING Crank Bearing - KTM 24-1099
MOOSE RACING
$39.95Worn crankshaft bearings are the silent killer of 2-stroke performance—they accelerate power loss, increase friction, and can lead to catastrophic engine failure if left unchecked. The MOOSE RACING...09240221- SKU:
- 09240221
- Availability:
- Ships Same Business Day
- Weight:
- 0.26 LBS
- TYPE:
- BALL
- APPLICATION:
- CRANKSHAFT
- PRODUCT NAME:
- BEARING
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$39.95 -
MOOSE RACING Complete Motor Gasket Kit - XR250 808263
MOOSE RACING
$75.94A complete engine and transmission rebuild requires precision-fit gaskets and seals that won't compromise your engine's integrity or performance. The MOOSE RACING Complete Motor Gasket Kit eliminates...09340135- SKU:
- 09340135
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- PRODUCT NAME:
- GASKET
- UNITS:
- KIT
- TYPE:
- ENGINE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
$75.94Qty in Cart: 0Quantity:Price:$75.94Subtotal: -
On Sale
VESRAH Complete Gasket Kit - KDX/KX 250 VG-453
VESRAH
MSRP: $48.73Now: $46.29Was: $48.73A complete engine rebuild demands precision gaskets that seal under extreme pressure and temperature cycling—compromising here invites oil leaks, compression loss, and premature failure. The VESRAH...VG453- SKU:
- VG453
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- SET
- PRODUCT NAME:
- GASKET
MSRP: $48.73Now: $46.29Was: $48.73Qty in Cart: 0Quantity:Price:MSRP: $48.73Now: $46.29Was: $48.73Subtotal: -
WSM Top-End Rebuild Kit - Platinum Series - Standard 010-841-10P
WSM
$391.70A top-end rebuild demands precision components engineered to withstand extreme combustion pressures and sustained RPM loads. The WSM Platinum Series delivers OEM-quality pistons paired with premium...01084110P- SKU:
- 01084110P
- Availability:
- Ships Same Business Day
- Weight:
- 4.80 LBS
- MODEL:
- PLATINUM SERIES
- PISTON SIZE METRIC:
- STANDARD
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- EACH
- BORE SIZE METRIC:
- 79.87 MM
- PRODUCT NAME:
- REBUILD KIT
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- TOP END
$391.70Qty in Cart: 0Quantity:Price:$391.70Subtotal: -
MOOSE RACING Circlip MSE72065K
MOOSE RACING
$3.95A precision circlip is essential for securing critical rotating components in high-performance engines and transmissions where vibration and lateral forces demand absolute reliability. This MOOSE...09130189- SKU:
- 09130189
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- PRODUCT NAME:
- CIRCLIP
- MATERIAL:
- STAINLESS STEEL
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- PISTON
- UNITS:
- SET
$3.95Qty in Cart: 0Quantity:Price:$3.95Subtotal: -
MOOSE RACING Top End Gasket - CRF230 810242
MOOSE RACING
$74.59A top-end rebuild demands precision gaskets and seals that won't fail under load—this Moose Racing set gives you OEM-quality components at a fraction of the cost. Whether you're replacing a worn...09340070- SKU:
- 09340070
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- GASKET
- TYPE:
- TOP END
- UNITS:
- KIT
- RIDING STYLE:
- OFF-ROAD
$74.59 -
On Sale
VESRAH Intake Valve GG-2013-IN
VESRAH
MSRP: $12.83Now: $12.19Was: $12.83Maintaining OEM-equivalent valve performance is critical for engine reliability and consistent combustion efficiency. The VESRAH Intake Valve GG-2013-IN is precision-manufactured to match factory...GG2013IN- SKU:
- GG2013IN
- Availability:
- Ships Same Business Day
- Weight:
- 0.13 LBS
- LENGTH METRIC:
- 93.80 MM
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- INTAKE
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- RIDING STYLE:
- STREET
- STEM DIAMETER METRIC:
- 6.00 MM
- HEAD DIAMETER:
- 34,00 MM
- HEAD DIAMETER METRIC:
- 34.00 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
MSRP: $12.83Now: $12.19Was: $12.83 -
On Sale
VESRAH Intake Valve GG-1040-IN
VESRAH
MSRP: $27.00Now: $25.65Was: $27.00A worn or damaged intake valve compromises combustion efficiency, throttle response, and fuel economy—potentially leading to costly engine damage if left unchecked. The VESRAH Intake Valve GG-1040-IN...09262806- SKU:
- 09262806
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- HEAD DIAMETER METRIC:
- 28.50 MM
- LENGTH METRIC:
- 96.60 MM
- PRODUCT NAME:
- VALVE
- STEM DIAMETER METRIC:
- 5.50 MM
- APPLICATION:
- INTAKE
- HEAD DIAMETER:
- 28,50 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- UNITS:
- 2 PIECE
MSRP: $27.00Now: $25.65Was: $27.00 -
On Sale
VESRAH Top End Gasket Kit - DS/JR80 VG-7089
VESRAH
MSRP: $36.36Now: $34.54Was: $36.36A top-end rebuild demands precision gaskets and seals that won't compromise combustion integrity or leak under pressure. The VESRAH VG-7089 gives you OEM-equivalent quality components in one complete...VG7089M- SKU:
- VG7089M
- Availability:
- Ships Same Business Day
- Weight:
- 0.36 LBS
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- TYPE:
- TOP END
- UNITS:
- SET
MSRP: $36.36Now: $34.54Was: $36.36Qty in Cart: 0Quantity:Price:MSRP: $36.36Now: $34.54Was: $36.36Subtotal: -
On Sale
VESRAH Complete Gasket Kit - TS185 VG-351
VESRAH
MSRP: $27.32Now: $25.95Was: $27.32A complete engine rebuild demands precision—and missed gaskets or seals create costly leaks and performance loss. The VESRAH VG351 gasket kit consolidates every critical seal you need in one package,...VG351- SKU:
- VG351
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- UNITS:
- SET
- TYPE:
- COMPLETE
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
MSRP: $27.32Now: $25.95Was: $27.32Qty in Cart: 0Quantity:Price:MSRP: $27.32Now: $25.95Was: $27.32Subtotal: -
On Sale
VESRAH Complete Gasket Kit - DS/TS 125 VG-355
VESRAH
MSRP: $44.14Now: $41.93Was: $44.14Engine gasket degradation is inevitable—heat cycles, pressure, and time break down seals and compromise compression. The VESRAH Complete Gasket Kit VG-355 eliminates guesswork by bundling every...VG355- SKU:
- VG355
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- COMPLETE
- UNITS:
- SET
MSRP: $44.14Now: $41.93Was: $44.14Qty in Cart: 0Quantity:Price:MSRP: $44.14Now: $41.93Was: $44.14Subtotal: -
On Sale
VESRAH Complete Gasket Kit - ALT/JR/LT50 VG-392
VESRAH
MSRP: $27.84Now: $26.45Was: $27.84A complete gasket kit is essential when rebuilding your ALT/JR/LT50 engine—missing even one seal can compromise compression and allow oil leakage that degrades performance and reliability. The VESRAH...VG392- SKU:
- VG392
- Availability:
- Ships Same Business Day
- Weight:
- 0.19 LBS
- TYPE:
- COMPLETE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- SET
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
MSRP: $27.84Now: $26.45Was: $27.84Qty in Cart: 0Quantity:Price:MSRP: $27.84Now: $26.45Was: $27.84Subtotal: -
POWERSTANDS RACING Case Saver/Sprocket Cover - Red 03-04152-24
POWERSTANDS RACING
$99.95A broken chain can catastrophically damage your engine case, turning a simple mechanical failure into thousands of dollars in repairs. The POWERSTANDS Racing Case Saver/Sprocket Cover replaces your...09500775- SKU:
- 09500775
- Availability:
- Ships Same Business Day
- Weight:
- 0.70 LBS
- RIDING STYLE:
- OFF-ROAD
- COLOR/FINISH:
- RED
- PRODUCT NAME:
- CASE SAVER
- TYPE:
- ENGINE
- COLOR/FINISH:
- ANODIZED
- PRODUCT NAME:
- SPROCKET COVER
- UNITS:
- EACH
$99.95Qty in Cart: 0Quantity:Price:$99.95Subtotal:
