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
-
MOOSE RACING Valve Shim - 7.48 x 3.40 - 5 pack MSE5PK748340
MOOSE RACING
$9.95Proper valve train geometry is non-negotiable for engine reliability and performance—especially during frequent adjustments or rebuilds. These MOOSE RACING valve shims eliminate guesswork with precision-forged construction and laser-etched...09261902- SKU:
- 09261902
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- SNOW
- OUTSIDE DIAMETER METRIC:
- 7.48 MM
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 3.40 MM
$9.95 -
MOOSE RACING Valve Shim - 7.48 x 3.45 - 5 pack MSE5PK748345
MOOSE RACING
$9.95Proper valve clearance is critical to engine longevity and performance—too tight and you risk burned valves, too loose and you lose power and increase wear. MOOSE RACING valve shims give you precise control over your valve train with reliable, forged...09261903- SKU:
- 09261903
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- VALVE SHIM THICKNESS METRIC:
- 3.45 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- OUTSIDE DIAMETER METRIC:
- 7.48 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
$9.95Qty in Cart: 0Quantity:Price:$9.95Subtotal: -
MOOSE RACING Valve Shim - 8.90 x 1.76 - 5 pack MSE5PK890176
MOOSE RACING
$10.95Precision valve train maintenance demands accurate, durable shims that won't let you down during critical tuning. These forged 4140 steel shims eliminate the guesswork of valve lash adjustment with laser-etched identification, so you spend less time...09261906- SKU:
- 09261906
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- TYPE:
- VALVE
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- MATERIAL:
- ROLLED
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 1.76 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
$10.95 -
MOOSE RACING Valve Shim - 8.90 x 1.84 - 5 pack MSE5PK890184
MOOSE RACING
$10.95Proper valve clearance is critical to engine performance and longevity—even a few thousandths of an inch off can hurt compression, increase valve train noise, and accelerate wear. The MOOSE RACING 8.90 x 1.84 valve shim kit eliminates guesswork during...09261908- SKU:
- 09261908
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- STREET
- VALVE SHIM THICKNESS METRIC:
- 1.84 MM
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
$10.95 -
MOOSE RACING Valve Shim - 9.48 x 2.10 - 5 pack MSE5PK948210
MOOSE RACING
$9.95Valve train maintenance demands precision, and these MOOSE RACING shims deliver exactly that. When you're dialing in your valve clearances, having a complete set of accurately-sized shims—laser-etched for instant identification—eliminates guesswork and...09261946- SKU:
- 09261946
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- SNOW
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- VALVE SHIM THICKNESS METRIC:
- 2.10 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
$9.95 -
MOOSE RACING Valve Shim - 9.48 x 2.15 - 5 pack MSE5PK948215
MOOSE RACING
$9.95Valve shim maintenance is critical to keeping your engine running at peak performance, and having quality shims on hand eliminates downtime during valve train adjustments. MOOSE Racing shims are forged from 4140 cold rolled steel—not sintered—which means...09261947- SKU:
- 09261947
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- MATERIAL:
- ROLLED
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 2.15 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
$9.95 -
MOOSE RACING Valve Shim - 9.48 x 2.25 - 5 pack MSE5PK948225
MOOSE RACING
$9.95Valve shim maintenance is critical for precise valve train geometry and consistent engine performance. These MOOSE RACING shims eliminate guesswork during valve adjustments by offering accurate, individually-sized components that won't degrade under...09261949- SKU:
- 09261949
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- VALVE SHIM THICKNESS METRIC:
- 2.25 MM
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- STREET
$9.95 -
MOOSE RACING Valve Shim - 9.48 x 2.30 - 5 pack MSE5PK948230
MOOSE RACING
$9.95Proper valve shim selection is critical for maintaining correct valve clearances and engine performance—neglecting this during maintenance can lead to loss of power, increased noise, and premature wear. This 5-pack of MOOSE RACING valve shims gives you...09261950- SKU:
- 09261950
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- 5 PACK
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- VALVE SHIM THICKNESS METRIC:
- 2.30 MM
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
$9.95 -
MOOSE RACING Valve Shim - 9.48 x 2.35 - 5 pack MSE5PK948235
MOOSE RACING
$9.95Valve shim maintenance is critical for maintaining proper valve clearances and extending your engine's service life. MOOSE RACING's forged 4140 cold-rolled steel shims eliminate guesswork with laser-etched size markings, ensuring you grab the right shim...09261951- SKU:
- 09261951
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- STREET
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 2.35 MM
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- SNOW
$9.95 -
MOOSE RACING Valve Shim - 9.48 x 2.40 - 5 pack MSE5PK948240
MOOSE RACING
$9.95Proper valve shim selection is critical for maintaining correct valve clearances and preventing costly engine damage or performance loss. These MOOSE RACING shims eliminate guesswork during valve train maintenance with laser-etched sizing and consistent...09261952- SKU:
- 09261952
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- VALVE SHIM THICKNESS METRIC:
- 2.40 MM
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- STREET
$9.95 -
MOOSE RACING Valve Shim - 9.48 x 2.45 - 5 pack MSE5PK948245
MOOSE RACING
$9.95Valve train maintenance demands precision, and guesswork has no place in your engine bay. These MOOSE RACING valve shims eliminate uncertainty with laser-etched sizing and forged 4140 steel construction that won't degrade under thermal cycling. Whether...09261953- SKU:
- 09261953
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- STREET
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 2.45 MM
$9.95 -
MOOSE RACING Valve Shim - 9.48 x 2.55 - 5 pack MSE5PK948255
MOOSE RACING
$9.95Maintaining precise valve clearances is critical to engine performance, longevity, and reliability—and having a complete shim kit on hand eliminates guesswork during valve train service. MOOSE RACING valve shims are forged from 4140 cold rolled steel,...09261955- SKU:
- 09261955
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 2.55 MM
$9.95 -
MOOSE RACING Valve Shim - 9.48 x 2.60 - 5 pack MSE5PK948260
MOOSE RACING
$9.95Precision valve train maintenance demands reliable, accurate shims that won't let you down mid-rebuild. These MOOSE RACING valve shims are forged from 4140 cold rolled steel—not sintered—delivering the durability and dimensional consistency that...09261956- SKU:
- 09261956
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- MATERIAL:
- ROLLED
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 2.60 MM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
$9.95 -
MOOSE RACING Valve Shim - 9.48 x 2.65 - 5 pack MSE5PK948265
MOOSE RACING
$9.95Maintaining proper valve clearance is critical to engine performance and longevity—and having precision shims on hand ensures you're never caught without the right size during a rebuild or adjustment. These MOOSE Racing shims are forged from 4140 cold...09261957- SKU:
- 09261957
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- MATERIAL:
- ROLLED
- RIDING STYLE:
- ATV
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 2.65 MM
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
$9.95 -
MOOSE RACING Clutch Cylinder Guard - 125/200 13-090
MOOSE RACING
$32.95Your hydraulic clutch cylinder is vulnerable to chain contact and impact damage—especially in high-stress racing environments. The MOOSE RACING Clutch Cylinder Guard delivers direct protection with integrated knockdown bars that manage chain movement...09500148- SKU:
- 09500148
- Availability:
- Ships Same Business Day
- Weight:
- 0.38 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COLOR/FINISH:
- BLACK
- MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- CASE SAVER
- RIDING STYLE:
- STREET
- TYPE:
- SLAVE CYLINDER
- COLOR/FINISH:
- ANODIZED
$32.95Qty in Cart: 0Quantity:Price:$32.95Subtotal: -
MOOSE RACING Clutch Cylinder Guard - 250/300 13-091
MOOSE RACING
$32.95Hydraulic clutch cylinders are vulnerable to chain strikes and debris during aggressive riding—a single impact can compromise your clutch engagement and sideline your bike. The MOOSE RACING Clutch Cylinder Guard provides robust CNC-machined protection...09500149- SKU:
- 09500149
- Availability:
- Ships Same Business Day
- Weight:
- 0.37 LBS
- TYPE:
- SLAVE CYLINDER
- COLOR/FINISH:
- BLACK
- MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- CASE SAVER
- RIDING STYLE:
- STREET
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COLOR/FINISH:
- ANODIZED
$32.95 -
MOOSE RACING Piston Kit - 53.94 mm MSE22189B
MOOSE RACING
$146.95If you're rebuilding an engine or recovering from ring blow-by, a quality piston kit is non-negotiable. MOOSE Racing's gravity-cast design with 18% silicon content resists wear and thermal distortion, giving you the reliability needed for consistent...09102669- SKU:
- 09102669
- Availability:
- Ships Same Business Day
- Weight:
- 0.37 LBS
- ENGINE TYPE:
- 2-STROKE
- STYLE:
- CAST REPLICA
- COMPRESSION RATIO IMPERIAL:
- STOCK
- PISTON DIAMETER METRIC:
- 53.94 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- UNITS:
- KIT
- DISPLACEMENT:
- 125 CC
- CYLINDER DIAMETER METRIC:
- 54.00 MM
- PRODUCT NAME:
- PISTON KIT
$146.95 -
MOOSE RACING Piston Kit - 53.94 mm MSE22685C
MOOSE RACING
$99.95A piston kit is one of the most critical internal upgrades for extending engine life and maintaining peak performance under high-load conditions. The MOOSE Racing MSE22685C combines gravity-cast aluminum with 18% silicon content to deliver exceptional...09102689- SKU:
- 09102689
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- PISTON DIAMETER METRIC:
- 53.94 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- PISTON KIT
- PISTON MATERIAL:
- ALUMINUM ALLOY
$99.95Qty in Cart: 0Quantity:Price:$99.95Subtotal: -
MOOSE RACING Piston Kit - 44.45 mm MSE22860B
MOOSE RACING
$113.35A piston kit is fundamental to engine longevity and reliability—especially under high-load conditions. The MOOSE RACING MSE22860B combines precision gravity-cast construction with wear-resistant coatings designed to minimize friction during break-in and...09102697- SKU:
- 09102697
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON DIAMETER METRIC:
- 44.45 MM
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$113.35 -
MOOSE RACING Cylinder - Standard - FC250 MSE50006
MOOSE RACING
$498.95A worn or damaged cylinder directly compromises engine performance, throttle response, and overall reliability. The MOOSE RACING Cylinder restores your FC250 to OEM specifications with precision-machined tolerances and a low-friction bore surface that...09310879- SKU:
- 09310879
- Availability:
- Ships Same Business Day
- Weight:
- 2.55 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- PRODUCT NAME:
- CYLINDER
- MATERIAL:
- ALUMINUM
- MATERIAL:
- CAST
$498.95
