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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Hot Cams Valve Shim 9.48mm x 3.25mm for Honda CRF450R 2002-2012 5PK948325
HOT CAMS
$10.95Valve clearance directly impacts your CRF450R's power delivery, fuel efficiency, and engine longevity. As your engine ages and components wear, shims shift and clearances drift—leaving performance on the table and risking valve damage. Hot Cams'...09261413- SKU:
- 09261413
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 3.25 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- MATERIAL:
- STEEL
$10.95 -
Hot Cams Valve Shim 9.48mm x 3.30mm for Honda CRF450R 2002-2018 5PK948330
HOT CAMS
$10.95Valve clearance directly impacts combustion efficiency, engine longevity, and overall performance—even small deviations from spec can rob you of horsepower and increase wear on critical components. This 5-pack of HOT CAMS valve shims gives you precision...09261414- SKU:
- 09261414
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 3.30 MM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
$10.95 -
Hot Cams Valve Shim 9.48mm x 3.45mm for Honda CRF450R 2002-2014 5PK948345
HOT CAMS
$10.95Proper valve clearance is critical to CRF450R performance—too tight and you risk bent valves, too loose and you lose power. Hot Cams valve shims are precision-engineered to hold exact tolerances, letting you dial in your clearance spec and keep your...09261417- SKU:
- 09261417
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- RIDING STYLE:
- STREET
- VALVE SHIM THICKNESS METRIC:
- 3.45 MM
- 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:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
$10.95 -
Hot Cams Valve Shim 7.48mm x 3.50mm for Honda CRF150R 2007-2016 5PK748350
HOT CAMS
$10.95Valve clearance directly impacts combustion efficiency, fuel economy, and engine longevity—and even minor deviations can cause performance loss or mechanical wear. The Hot Cams Valve Shim 7.48mm x 3.50mm is a precision replacement designed to restore...09261348- SKU:
- 09261348
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- OUTSIDE DIAMETER METRIC:
- 7.48 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- VALVE SHIM THICKNESS METRIC:
- 3.50 MM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
$10.95Qty in Cart: 0Quantity:Price:$10.95Subtotal: -
Hot Cams Valve Shim 8.90 x 1.80 for KTM 250 SX-F 2005-2011 5PK890180
HOT CAMS
$11.95Valve clearance directly impacts combustion efficiency, engine longevity, and peak performance on your KTM 250 SX-F. Over time, thermal cycling causes valve seats to wear, requiring shim adjustments to maintain optimal clearance tolerances. This 5-pack...09261351- SKU:
- 09261351
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- RIDING STYLE:
- STREET
- VALVE SHIM THICKNESS METRIC:
- 1.80 MM
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
$11.95 -
Hot Cams Valve Shim 8.90mm x 1.92mm for KTM 250 SX-F 2005-2022 5PK890192
HOT CAMS
$11.95Valve clearance directly impacts engine performance, fuel efficiency, and longevity—making proper shim selection critical for KTM 250 SX-F owners. This HOT CAMS valve shim set provides the precise dimensions needed to dial in exact clearances, whether...09261354- SKU:
- 09261354
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- VALVE SHIM THICKNESS METRIC:
- 1.92 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
$11.95 -
Hot Cams Valve Shim 8.90mm x 2.60mm for KTM 250 SX-F 2005-2011 5PK890260
HOT CAMS
$11.95Valve clearance directly impacts combustion efficiency, valve longevity, and overall engine performance—even a few hundredths of a millimeter out of spec can rob you of power and create premature wear. The HOT CAMS Valve Shim 8.90mm x 2.60mm gives you...09261371- SKU:
- 09261371
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 8.90 MM
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 2.60 MM
- RIDING STYLE:
- STREET
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
$11.95Qty in Cart: 0Quantity:Price:$11.95Subtotal: -
Hot Cams Valve Shim 9.48mm x 1.25mm for Honda CRF450R 2002-2014 5PK948125
HOT CAMS
$10.95Valve clearance drift is inevitable in high-revving engines, and running incorrect shim sizes compromises both performance and engine longevity. The Hot Cams Valve Shim 9.48mm x 1.25mm pack gives you five precision-engineered replacements ready for when...09261373- SKU:
- 09261373
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- MATERIAL:
- STEEL
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- TYPE:
- VALVE
- VALVE SHIM THICKNESS METRIC:
- 1.25 MM
$10.95Qty in Cart: 0Quantity:Price:$10.95Subtotal: -
Hot Cams Valve Shim 9.48mm x 1.30mm for Honda CRF450R 2002-2012 5PK948130
HOT CAMS
$10.95Valve clearance directly impacts engine efficiency, combustion timing, and overall performance—even slight deviations can lead to power loss or engine damage. These HOT CAMS valve shims maintain precise clearance specifications on your CRF450R, ensuring...09261374- SKU:
- 09261374
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- MATERIAL:
- STEEL
- VALVE SHIM THICKNESS METRIC:
- 1.30 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
$10.95 -
Hot Cams Valve Shim 9.48mm x 1.60mm for Honda CRF450R 2002-2014 5PK948160
HOT CAMS
$10.95Valve clearance directly impacts your CRF450R's power delivery, fuel efficiency, and engine longevity. Over time, valve shims wear and compress, throwing off precise tolerances that keep your four-stroke running at peak efficiency. This 5-pack of Hot...09261380- SKU:
- 09261380
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- VALVE SHIM THICKNESS METRIC:
- 1.60 MM
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- ATV
$10.95Qty in Cart: 0Quantity:Price:$10.95Subtotal: -
Hot Cams Valve Shim 9.48mm x 1.65mm for Honda CRF450R 2002-2016 5PK948165
HOT CAMS
$10.95Valve clearance drift is inevitable with engine wear—ignoring it costs you horsepower, increases noise, and risks catastrophic valve damage. The Hot Cams 9.48mm x 1.65mm valve shim pack delivers the precision adjustments your Honda CRF450R needs to...09261381- SKU:
- 09261381
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- VALVE SHIM THICKNESS METRIC:
- 1.65 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- MATERIAL:
- STEEL
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
$10.95 -
Hot Cams Valve Shim 9.48mm x 1.70mm for Honda CRF450R 2002-2018 5PK948170
HOT CAMS
$10.95Valve clearance directly affects your CRF450R's power delivery, fuel efficiency, and engine longevity. Hot Cams valve shims are precision-engineered to maintain exact clearance specifications—critical for competitive racing and reliable trail riding...09261382- SKU:
- 09261382
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 1.70 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
$10.95Qty in Cart: 0Quantity:Price:$10.95Subtotal: -
Hot Cams Valve Shim 9.48mm x 3.10mm for Honda CRF450R 2002-2012 5PK948310
HOT CAMS
$10.95Valve clearance directly impacts combustion efficiency, fuel economy, and engine longevity—and worn shims compromise all three. This five-pack of Hot Cams valve shims keeps your CRF450R's valve train operating at factory specifications, preventing costly...09261410- SKU:
- 09261410
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- RIDING STYLE:
- STREET
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- UNITS:
- 5 PACK
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
- VALVE SHIM THICKNESS METRIC:
- 3.10 MM
$10.95 -
Hot Cams Valve Shim 9.48mm x 3.20mm for Honda CRF450R 2002-2014 5PK948320
HOT CAMS
$10.95Proper valve clearance is critical to engine longevity and performance—even a few thousandths of an inch out of spec can cause premature wear, valve float, and power loss. The Hot Cams Valve Shim 9.48mm x 3.20mm is a direct replacement for Honda CRF450R...09261412- SKU:
- 09261412
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- STREET
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 3.20 MM
- MATERIAL:
- STEEL
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- ATV
- TYPE:
- VALVE
$10.95 -
Hot Cams Valve Shim 9.48mm x 3.35mm for Honda CRF450R 2002-2012 5PK948335
HOT CAMS
$10.95Valve shim wear is one of the most common causes of improper valve clearance and loss of power output in high-mileage CRF450R engines. Hot Cams replacement shims restore precise valve adjustment, ensuring optimal engine efficiency and preventing costly...09261415- SKU:
- 09261415
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- ATV
- RIDING STYLE:
- STREET
- VALVE SHIM THICKNESS METRIC:
- 3.35 MM
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- MATERIAL:
- STEEL
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- OFF-ROAD
$10.95 -
Hot Cams Valve Shim Kit for Honda CRF450R 2002-2018 5PK948340
HOT CAMS
$10.95Valve clearance directly impacts engine performance, fuel efficiency, and longevity—and worn or incorrect shims compromise all three. The Hot Cams Valve Shim Kit delivers precision-engineered replacements to restore optimal clearance on your CRF450R,...09261416- SKU:
- 09261416
- Availability:
- Ships Same Business Day
- Weight:
- 0.03 LBS
- OUTSIDE DIAMETER METRIC:
- 9.48 MM
- RIDING STYLE:
- SNOW
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- SHIM
- RIDING STYLE:
- UTV
- RIDING STYLE:
- WATERCRAFT
- TYPE:
- VALVE
- UNITS:
- 5 PACK
- VALVE SHIM THICKNESS METRIC:
- 3.40 MM
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- RIDING STYLE:
- ATV
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
$10.95 -
On Sale
PROX Piston - GP 760 Waverunner 01.2514.050
PROX
MSRP: $138.95Now: $110.00Was: $138.95Piston for watercraft applications09102745- SKU:
- 09102745
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
- BORE SIZE METRIC:
- 84.50 MM
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- EACH
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
MSRP: $138.95Now: $110.00Was: $138.95 -
On Sale
PROX Piston - GP 760 Waverunner 01.2514.100
PROX
MSRP: $129.95Now: $110.00Was: $129.95Piston for watercraft applications09102747- SKU:
- 09102747
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- WATERCRAFT
- PISTON MATERIAL:
- ALUMINUM
- ENGINE TYPE:
- 2-STROKE
- UNITS:
- EACH
- BORE SIZE METRIC:
- 85.00 MM
MSRP: $129.95Now: $110.00Was: $129.95Qty in Cart: 0Quantity:Price:MSRP: $129.95Now: $110.00Was: $129.95Subtotal: -
On Sale
PROX Ring Set 02.1111
PROX
MSRP: $24.95Now: $21.00Was: $24.95Piston rings are fundamental to engine sealing and compression—worn or substandard rings directly compromise power output, fuel efficiency, and oil consumption. The PROX Ring Set 02.1111 delivers OEM-equivalent performance with Japanese manufacturing...09120161- SKU:
- 09120161
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- PRODUCT NAME:
- PISTON RING
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- SET
- PISTON MATERIAL:
- ALUMINUM ALLOY
MSRP: $24.95Now: $21.00Was: $24.95 -
On Sale
PROX Piston Kit - KTM300EXC '17-'18 01.6387.B
PROX
MSRP: $189.95Now: $161.00Was: $189.95When your KTM 300 EXC demands peak performance and reliability, OEM-spec pistons are non-negotiable. The PROX Piston Kit delivers factory-equivalent durability with precision Japanese engineering, ensuring consistent combustion, reduced blow-by, and...09106265- SKU:
- 09106265
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- PISTON KIT
MSRP: $189.95Now: $161.00Was: $189.95Qty in Cart: 0Quantity:Price:MSRP: $189.95Now: $161.00Was: $189.95Subtotal:
