Dirt Bike Engine Valves and Parts
Dirt Bike Engine Valves & Parts: Kibblewhite Black Diamond Exhaust Valves & Spring Kits at JJ Motorsports
Upgrade your dirt bike's valvetrain for maximum flow, heat resistance, and durability with premium valves and parts from JJ Motorsports, precision-engineered for superior performance in motocross, enduro, and trail riding. Our selection includes Black Diamond stainless steel exhaust valves, high-RPM spring kits, keepers, seals, and guides designed for increased lift, reduced wear, and reliable operation under extreme valve float conditions. Compatible with popular 4-stroke models like Honda CRF, Yamaha YZ/WR, KTM SX/EXC, and more, these Kibblewhite components feature one-piece forging, nitride coatings, and dual-spring technology to enhance airflow, prevent valve train failure, and support big-bore or high-compression builds. From exhaust valves with swirl-polished stems to titanium retainer spring kits for lightweight strength, rebuild your cylinder head for championship-level power, longevity, and confidence on every rev.
Shop trusted brands like Kibblewhite for race-proven quality. Explore related categories such as dirt bike piston and ring kits for full top-end rebuilds or dirt bike engine for camshafts and gaskets.
Top Dirt Bike Valve & Parts
- Kibblewhite Valve - Exhaust - Black Diamond 30-33616 – One-piece Black Diamond stainless steel exhaust valve with nitride coating, swirl-polished stem, and hard tip; designed for high-RPM durability and flow in 4-stroke engines.
- Kibblewhite Spring Kit 40-41600 – Dual-spring kit with titanium retainers, chromoly seats, and high-strength springs; supports increased lift and RPM while preventing valve float in performance builds.
Browse our in-stock inventory below with same-day shipping and expert support. Free shipping on orders over $99! Questions? Contact us for fitment advice!
- Product
- Qty in Cart
- Quantity
- Price
- Subtotal
-
PROX Valve and Spring Kit 28.SIS4336-2
PROX
$149.95If you're running your engine hard, stock valves and springs become a liability. The PROX 28.SIS4336-2 Kit replaces worn or inadequate OEM components with nitrided steel valves and premium chrome vanadium springs engineered to handle sustained high-RPM...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
$149.95If you're pushing your engine to its limits, OEM valve springs won't cut it—they're designed for stock RPM ranges and can't handle the demands of high-performance driving. The PROX Valve and Spring Kit 28.SIS4338-2 upgrades you to nitrided steel valves...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 Exhaust Valve 28.1340-1
PROX
$46.95A precision exhaust valve is critical to your engine's breathing efficiency and thermal management. The PROX 28.1340-1 delivers OEM-specification reliability without compromise, ensuring consistent valve sealing and longevity under sustained performance...09261419- SKU:
- 09261419
- Availability:
- Ships Same Business Day
- Weight:
- 0.07 LBS
- MATERIAL:
- STEEL
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$46.95 -
PROX Exhaust Valve 28.1409-1
PROX
$44.95Exhaust valve performance directly impacts combustion efficiency and engine longevity—especially under high RPM conditions where precision tolerances mean the difference between reliable power and catastrophic failure. The PROX 28.1409-1 is manufactured...09261421- 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
$139.95If you're running your engine hard, OEM valves and springs become a liability under sustained high-RPM operation. The PROX 28.SES2440-1 kit replaces these weak points with nitrided steel valves and premium chrome vanadium springs, engineered to handle...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
$155.95OEM valve springs lose their tension under sustained high-RPM operation, leading to valve float and catastrophic engine failure. The PROX Valve and Spring Kit 28.SES6327-1 replaces those compromised components with nitrided steel valves and premium...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
$155.95Qty in Cart: 0Quantity:Price:$155.95Subtotal: -
PROX Valve and Spring Kit 28.SES6329-1
PROX
$155.95If you're running your engine hard, OEM valves and springs will hold you back. The PROX 28.SES6329-1 Kit replaces weak factory components with nitrided steel valves and premium chrome vanadium springs engineered to handle sustained high-RPM abuse without...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
$155.95 -
PROX Valve and Spring Kit 28.SIS1409-2
PROX
$139.95High-RPM applications demand valve components that can withstand extreme heat, pressure, and cycling without degradation—stock valves simply won't cut it. The PROX Valve and Spring Kit upgrades your engine with nitrided steel valves and premium chrome...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
$139.95If you're pushing your engine to the limit, your OEM valves and springs won't keep pace. The PROX 28.SIS2440-2 Kit replaces worn or inadequate factory components with nitrided steel valves and premium chrome vanadium springs engineered to handle extreme...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
$149.95If you're running high-RPM applications or building a race engine, OEM valve assemblies won't cut it. The PROX Valve and Spring Kit 28.SIS6327-2 replaces stock valves and springs with nitrided steel construction and premium chrome vanadium springs...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
$149.95Qty in Cart: 0Quantity:Price:$149.95Subtotal: -
PROX Intake Valve and Spring Kit 28.SIS1340-2
PROX
$155.95If you're running higher RPMs or pushing your engine beyond stock parameters, OEM valve springs will eventually lose their ability to control valve timing under load—leading to float, missed shifts, and catastrophic engine damage. The PROX Intake Valve...09262892- SKU:
- 09262892
- Availability:
- Ships Same Business Day
- Weight:
- 0.30 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- VALVE AND SPRING KIT
$155.95 -
PROX Valve and Spring Kit 28.SES2414-1
PROX
$155.95If you're pushing your engine to its limits, factory valve and spring assemblies become a liability. The PROX 28.SES2414-1 kit replaces worn OEM components with nitrided steel valves and premium chrome vanadium springs engineered to withstand sustained...09262724- SKU:
- 09262724
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- VALVE AND SPRING KIT
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- VALVE
- UNITS:
- KIT
$155.95Qty in Cart: 0Quantity:Price:$155.95Subtotal: -
PROX Valve and Spring Kit 28.SES2444-1
PROX
$159.95If you're running your engine at sustained high RPM or pushing it beyond stock parameters, OEM valve springs will eventually lose their snap—and valve float becomes a real problem. The PROX Valve and Spring Kit 28.SES2444-1 pairs durable nitrided steel...09262725- SKU:
- 09262725
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- SPRING KIT
- UNITS:
- KIT
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- VALVE
$159.95Qty in Cart: 0Quantity:Price:$159.95Subtotal: -
PROX Valve and Spring Kit 28.SIS2414-2
PROX
$155.95If you're pushing your engine to its limits, OEM valves and springs won't cut it. The PROX 28.SIS2414-2 Kit replaces those weak factory components with nitrided steel valves and premium chrome vanadium springs engineered to handle extreme RPM and...09262728- SKU:
- 09262728
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- VALVE
- PRODUCT NAME:
- VALVE AND SPRING KIT
- UNITS:
- KIT
$155.95 -
PROX Valve and Spring Kit 28.SIS2444-2
PROX
$166.95If you're running high-RPM applications or pushing your engine beyond stock parameters, OEM valve springs will struggle to keep pace with valve float and premature wear. The PROX Valve and Spring Kit 28.SIS2444-2 replaces both intake and exhaust valves...09262729- SKU:
- 09262729
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- VALVE
- PRODUCT NAME:
- VALVE AND SPRING KIT
- UNITS:
- KIT
$166.95 -
PROX Exhaust Valve 28.1334-1
PROX
$40.95Proper valve operation is critical to engine reliability and performance—a compromised exhaust valve leads to lost compression, increased emissions, and potential catastrophic engine damage. The PROX 28.1334-1 is engineered to OEM specifications,...09260143- SKU:
- 09260143
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
- PRODUCT NAME:
- VALVE
- UNITS:
- EACH
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- EXHAUST
$40.95 -
PROX Exhaust Valve 28.1402-1
PROX
$40.95Proper valve clearance and sealing are critical to engine performance and longevity—a worn or damaged exhaust valve directly impacts compression, combustion efficiency, and power output. The PROX Exhaust Valve 28.1402-1 is engineered to OEM...09260144- SKU:
- 09260144
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- VALVE
- UNITS:
- EACH
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
$40.95 -
PROX Exhaust Valve 28.1495-1
PROX
$35.95A precision exhaust valve is critical to maintaining proper engine breathing and combustion efficiency, directly impacting power output and engine longevity. The PROX 28.1495-1 is engineered to OEM specifications, ensuring reliable performance whether...09260145- SKU:
- 09260145
- Availability:
- Ships Same Business Day
- Weight:
- 0.12 LBS
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- EXHAUST
$35.95Qty in Cart: 0Quantity:Price:$35.95Subtotal: -
PROX Exhaust Valve 28.1654-1
PROX
$56.95Exhaust valve performance directly impacts engine efficiency, combustion temperature management, and overall power delivery. The PROX 28.1654-1 is precision-engineered to OEM specifications, ensuring reliable sealing and consistent valve timing across...09260146- SKU:
- 09260146
- Availability:
- Ships Same Business Day
- Weight:
- 0.12 LBS
- RIDING STYLE:
- OFF-ROAD
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- UNITS:
- EACH
- APPLICATION:
- EXHAUST
$56.95 -
PROX Exhaust Valve 28.3402-1
PROX
$35.95A worn or damaged exhaust valve compromises engine breathing, power delivery, and fuel efficiency—forcing your engine to work harder for less performance. The PROX Exhaust Valve 28.3402-1 restores proper valve sealing and thermal management, ensuring...09260147- SKU:
- 09260147
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- VALVE
$35.95
