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
-
Hot Cams Valve Shim 9.48mm x 3.25mm for Honda CRF450R 2002-2012 5PK948325
HOT CAMS
$11.50Valve 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...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
$11.50 -
Hot Cams Valve Shim 9.48mm x 3.30mm for Honda CRF450R 2002-2018 5PK948330
HOT CAMS
$11.50Valve 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...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
$11.50 -
Hot Cams Valve Shim 9.48mm x 3.45mm for Honda CRF450R 2002-2014 5PK948345
HOT CAMS
$11.50Proper 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,...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
$11.50 -
Hot Cams Valve Shim 7.48mm x 3.50mm for Honda CRF150R 2007-2016 5PK748350
HOT CAMS
$11.50Valve 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...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
$11.50 -
Hot Cams Valve Shim 8.90 x 1.80 for KTM 250 SX-F 2005-2011 5PK890180
HOT CAMS
$12.55Valve 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...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
$12.55 -
Hot Cams Valve Shim 8.90mm x 1.92mm for KTM 250 SX-F 2005-2022 5PK890192
HOT CAMS
$12.55Valve 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...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
$12.55 -
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...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
$11.50Valve 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...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
$11.50 -
Hot Cams Valve Shim 9.48mm x 1.30mm for Honda CRF450R 2002-2012 5PK948130
HOT CAMS
$11.50Valve 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...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
$11.50 -
Hot Cams Valve Shim 9.48mm x 1.60mm for Honda CRF450R 2002-2014 5PK948160
HOT CAMS
$11.50Valve 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...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
$11.50 -
Hot Cams Valve Shim 9.48mm x 1.65mm for Honda CRF450R 2002-2016 5PK948165
HOT CAMS
$11.50Valve 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...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
$11.50 -
Hot Cams Valve Shim 9.48mm x 1.70mm for Honda CRF450R 2002-2018 5PK948170
HOT CAMS
$11.50Valve clearance directly affects your CRF450R's power delivery, fuel efficiency, and engine longevity. Hot Cams valve shims are precision-engineered to maintain exact clearance...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
$11.50 -
Hot Cams Valve Shim 9.48mm x 3.10mm for Honda CRF450R 2002-2012 5PK948310
HOT CAMS
$11.50Valve 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...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
$11.50 -
Hot Cams Valve Shim 9.48mm x 3.20mm for Honda CRF450R 2002-2014 5PK948320
HOT CAMS
$11.50Proper 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...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
$11.50 -
Hot Cams Valve Shim 9.48mm x 3.35mm for Honda CRF450R 2002-2012 5PK948335
HOT CAMS
$11.50Valve 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,...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
$11.50 -
Hot Cams Valve Shim Kit for Honda CRF450R 2002-2018 5PK948340
HOT CAMS
$11.50Valve 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...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
$11.50 -
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...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,...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:
