Dirt Bike Engine
Discover a full range of dirt bike engine components for rebuilding or upgrading your performance. 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.
- Product
- Qty in Cart
- Quantity
- Price
- Subtotal
-
PROX Valve and Spring Kit 28.SIS1336-2
PROX
$149.95PROX Valve and Spring Kit 28.SIS1336-2Replaces the OEM valves and valve springs, Steel, nitrided valves for increased durability and less wear under extreme conditions, Stronger valve springs deal with the extra weight of the steel valves, Springs are...09261458- SKU:
- 09261458
- Availability:
- Ships Same Business Day
- Weight:
- 0.29 LBS
- PRODUCT NAME:
- SPRING KIT
- TYPE:
- VALVE
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$149.95 -
PROX Valve and Spring Kit 28.SIS1337-2
PROX
$149.95PROX Valve and Spring Kit 28.SIS1337-2Replaces the OEM valves and valve springs, Steel, nitrided valves for increased durability and less wear under extreme conditions, Stronger valve springs deal with the extra weight of the steel valves, Springs are...09261459- SKU:
- 09261459
- Availability:
- Ships Same Business Day
- Weight:
- 0.29 LBS
- PRODUCT NAME:
- SPRING KIT
- TYPE:
- VALVE
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- INTAKE
- UNITS:
- KIT
$149.95Qty in Cart: 0Quantity:Price:$149.95Subtotal: -
PROX Intake Valve and Spring Kit 28.SIS3338-2
PROX
$149.95PROX Intake Valve and Spring Kit 28.SIS3338-2Replaces the OEM valves and valve springs, Steel, nitrided valves for increased durability and less wear under extreme conditions, Stronger valve springs deal with the extra weight of the steel valves, Springs...09261461- SKU:
- 09261461
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- APPLICATION:
- INTAKE
- PRODUCT NAME:
- SPRING KIT
- TYPE:
- VALVE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MATERIAL:
- TI-STEEL
$149.95 -
PROX Valve and Spring Kit 28.SIS4335-2
PROX
$149.95PROX Valve and Spring Kit 28.SIS4335-2Replaces the OEM valves and valve springs, Steel, nitrided valves for increased durability and less wear under extreme conditions, Stronger valve springs deal with the extra weight of the steel valves, Springs are...09261462- SKU:
- 09261462
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- TYPE:
- VALVE
- MATERIAL:
- STEEL
- APPLICATION:
- INTAKE
- PRODUCT NAME:
- SPRING KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$149.95 -
PROX Valve and Spring Kit 28.SIS4336-2
PROX
$149.95PROX Valve and Spring Kit 28.SIS4336-2Replaces the OEM valves and valve springs, Steel, nitrided valves for increased durability and less wear under extreme conditions, Stronger valve springs deal with the extra weight of the steel valves, Springs are...09261463- SKU:
- 09261463
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- PRODUCT NAME:
- SPRING KIT
- TYPE:
- VALVE
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$149.95Qty in Cart: 0Quantity:Price:$149.95Subtotal: -
PROX Valve and Spring Kit 28.SIS4338-2
PROX
$149.95PROX Valve and Spring Kit 28.SIS4338-2Replaces the OEM valves and valve springs, Steel, nitrided valves for increased durability and less wear under extreme conditions, Stronger valve springs deal with the extra weight of the steel valves, Springs are...09261464- SKU:
- 09261464
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- TYPE:
- VALVE
- PRODUCT NAME:
- SPRING KIT
- UNITS:
- KIT
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
$149.95 -
PROX Valve and Spring Kit 28.SIS4341-2
PROX
$149.95PROX Valve and Spring Kit 28.SIS4341-2Replaces the OEM valves and valve springs, Steel, nitrided valves for increased durability and less wear under extreme conditions, Stronger valve springs deal with the extra weight of the steel valves, Springs are...09261465- SKU:
- 09261465
- Availability:
- Ships Same Business Day
- Weight:
- 0.35 LBS
- APPLICATION:
- INTAKE
- PRODUCT NAME:
- SPRING KIT
- TYPE:
- VALVE
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$149.95 -
PROX Exhaust Valve 28.1340-1
PROX
$44.95PROX Exhaust Valve 28.1340-1Manufactured to the highest precision and quality, Constructed to meet OEM specifications, Available in standard sizes only09261419- SKU:
- 09261419
- Availability:
- Ships Same Business Day
- Weight:
- 0.07 LBS
- MATERIAL:
- STEEL
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$44.95 -
PROX Exhaust Valve 28.1409-1
PROX
$44.95PROX Exhaust Valve 28.1409-1Manufactured to the highest precision and quality, Constructed to meet OEM specifications, Available in standard sizes only09261421- SKU:
- 09261421
- Availability:
- Ships Same Business Day
- Weight:
- 0.09 LBS
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- VALVE
- UNITS:
- EACH
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
$44.95 -
PROX Valve and Spring Kit 28.SES2440-1
PROX
$139.95PROX Valve and Spring Kit 28.SES2440-1Replaces the OEM valves and valve springs, Steel, nitrided valves for increased durability and less wear under extreme conditions, Stronger valve springs deal with the extra weight of the steel valves, Springs are...09261427- SKU:
- 09261427
- Availability:
- Ships Same Business Day
- Weight:
- 0.24 LBS
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- SPRING KIT
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- VALVE
$139.95 -
PROX Valve and Spring Kit 28.SES6327-1
PROX
$149.95PROX Valve and Spring Kit 28.SES6327-1Replaces the OEM valves and valve springs, Steel, nitrided valves for increased durability and less wear under extreme conditions, Stronger valve springs deal with the extra weight of the steel valves, Springs are...09261429- SKU:
- 09261429
- Availability:
- Ships Same Business Day
- Weight:
- 0.26 LBS
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- SPRING KIT
- TYPE:
- VALVE
$149.95 -
PROX Valve and Spring Kit 28.SES6329-1
PROX
$149.95PROX Valve and Spring Kit 28.SES6329-1Replaces the OEM valves and valve springs, Steel, nitrided valves for increased durability and less wear under extreme conditions, Stronger valve springs deal with the extra weight of the steel valves, Springs are...09261430- SKU:
- 09261430
- Availability:
- Ships Same Business Day
- Weight:
- 0.24 LBS
- APPLICATION:
- EXHAUST
- TYPE:
- VALVE
- PRODUCT NAME:
- SPRING KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MATERIAL:
- STEEL
$149.95 -
PROX Valve and Spring Kit 28.SIS1409-2
PROX
$139.95PROX Valve and Spring Kit 28.SIS1409-2Replaces the OEM valves and valve springs, Steel, nitrided valves for increased durability and less wear under extreme conditions, Stronger valve springs deal with the extra weight of the steel valves, Springs are...09261431- SKU:
- 09261431
- Availability:
- Ships Same Business Day
- Weight:
- 0.31 LBS
- APPLICATION:
- INTAKE
- PRODUCT NAME:
- SPRING KIT
- TYPE:
- VALVE
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$139.95 -
PROX Valve and Spring Kit 28.SIS2440-2
PROX
$139.95PROX Valve and Spring Kit 28.SIS2440-2Replaces the OEM valves and valve springs, Steel, nitrided valves for increased durability and less wear under extreme conditions, Stronger valve springs deal with the extra weight of the steel valves, Springs are...09261432- SKU:
- 09261432
- Availability:
- Ships Same Business Day
- Weight:
- 0.34 LBS
- PRODUCT NAME:
- SPRING KIT
- TYPE:
- VALVE
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- INTAKE
$139.95Qty in Cart: 0Quantity:Price:$139.95Subtotal: -
PROX Valve and Spring Kit 28.SIS6327-2
PROX
$149.95PROX Valve and Spring Kit 28.SIS6327-2Replaces the OEM valves and valve springs, Steel, nitrided valves for increased durability and less wear under extreme conditions, Stronger valve springs deal with the extra weight of the steel valves, Springs are...09261435- SKU:
- 09261435
- Availability:
- Ships Same Business Day
- Weight:
- 0.27 LBS
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- APPLICATION:
- INTAKE
- PRODUCT NAME:
- SPRING KIT
- TYPE:
- VALVE
$149.95 -
PROX Piston Kit 01.1113.B
PROX
$89.95PROX Piston Kit 01.1113.BManufactured in Japan and designed to be OEM replacement, Cast from a high-silicon-content aluminum alloy that meets or exceeds OEM specifications, then CNC-machined to extremely close tolerances, Pistons supplied in a kit...09100020- SKU:
- 09100020
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 47.45 MM
- ENGINE TYPE:
- 2-STROKE
- PISTON SIZE METRIC:
- STANDARD SIZE B
- PISTON DIAMETER METRIC:
- 47.45 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
$89.95 -
PROX Piston Kit 01.1113.C
PROX
$89.95PROX Piston Kit 01.1113.CManufactured in Japan and designed to be OEM replacement, Cast from a high-silicon-content aluminum alloy that meets or exceeds OEM specifications, then CNC-machined to extremely close tolerances, Pistons supplied in a kit...09100021- SKU:
- 09100021
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PISTON DIAMETER METRIC:
- 47.46 MM
- PISTON SIZE METRIC:
- STANDARD SIZE C
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 47.46 MM
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
- PRODUCT NAME:
- PISTON KIT
$89.95 -
PROX Piston Kit 01.4022.A
PROX
$79.95PROX Piston Kit 01.4022.AManufactured in Japan and designed to be OEM replacement, Cast from a high-silicon-content aluminum alloy that meets or exceeds OEM specifications, then CNC-machined to extremely close tolerances, Pistons supplied in a kit...09100022- SKU:
- 09100022
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- BORE SIZE METRIC:
- 44.45 MM
- PISTON DIAMETER METRIC:
- 42.96 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- EACH
- PISTON SIZE METRIC:
- STANDARD SIZE A
- RIDING STYLE:
- OFF-ROAD
$79.95 -
PROX Piston Kit 01.4022.B
PROX
$79.95PROX Piston Kit 01.4022.BManufactured in Japan and designed to be OEM replacement, Cast from a high-silicon-content aluminum alloy that meets or exceeds OEM specifications, then CNC-machined to extremely close tolerances, Pistons supplied in a kit...09100023- SKU:
- 09100023
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- BORE SIZE METRIC:
- 44.46 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- EACH
- PISTON DIAMETER METRIC:
- 44.46 MM
- PISTON SIZE METRIC:
- STANDARD SIZE B
- RIDING STYLE:
- OFF-ROAD
$79.95 -
PROX Piston Kit 01.4223.B
PROX
$105.95PROX Piston Kit 01.4223.BManufactured in Japan and designed to be OEM replacement, Cast from a high-silicon-content aluminum alloy that meets or exceeds OEM specifications, then CNC-machined to extremely close tolerances, Pistons supplied in a kit...09100025- SKU:
- 09100025
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON DIAMETER METRIC:
- 53.96 MM
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 2-STROKE
- PISTON SIZE METRIC:
- STANDARD SIZE B
- UNITS:
- EACH
- BORE SIZE METRIC:
- 53.96 MM
- PRODUCT NAME:
- PISTON KIT
$105.95Qty in Cart: 0Quantity:Price:$105.95Subtotal:
