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
-
On Sale
PROX Valve and Spring Kit 28.SIS3408-2
PROX
MSRP: $143.95Now: $119.00Was: $143.95If you're pushing your engine beyond stock limits, OEM valves and springs become your weak link. The PROX 28.SIS3408-2 Valve and Spring Kit replaces those components with hardened steel valves and premium chrome vanadium springs engineered to handle...09261039- SKU:
- 09261039
- Availability:
- Ships Same Business Day
- Weight:
- 0.32 LBS
- PRODUCT NAME:
- SPRING KIT
- TYPE:
- VALVE
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $143.95Now: $119.00Was: $143.95 -
On Sale
PROX Valve and Spring Kit 28.SES3408-1
PROX
MSRP: $143.95Now: $119.00Was: $143.95If you're running high-RPM applications or pushing your engine beyond stock limits, OEM valve and spring assemblies become a liability. The PROX 28.SES3408-1 replaces weak factory components with nitrided steel valves and premium chrome vanadium springs...09261040- SKU:
- 09261040
- Availability:
- Ships Same Business Day
- Weight:
- 0.26 LBS
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- VALVE
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- SPRING KIT
MSRP: $143.95Now: $119.00Was: $143.95 -
On Sale
PROX Exhaust Valve 28.1070-1
PROX
MSRP: $25.95Now: $21.00Was: $25.95A precision exhaust valve is critical to maintaining proper scavenging, reducing backpressure, and maximizing power output in high-revving engines. The PROX 28.1070-1 delivers OEM-equivalent sealing and durability, making it an essential replacement for...09260664- SKU:
- 09260664
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- APPLICATION:
- EXHAUST
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
MSRP: $25.95Now: $21.00Was: $25.95 -
On Sale
PROX Intake Valve 28.1070-2
PROX
MSRP: $17.95Now: $13.00Was: $17.95A properly functioning intake valve is critical to your engine's breathing efficiency and combustion reliability. The PROX 28.1070-2 is precision-manufactured to OEM specifications, ensuring consistent sealing and optimal airflow into your combustion...09260665- SKU:
- 09260665
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- UNITS:
- EACH
MSRP: $17.95Now: $13.00Was: $17.95 -
On Sale
PROX Exhaust Valve 28.1226-1
PROX
MSRP: $30.95Now: $25.00Was: $30.95A precision exhaust valve is critical to maintaining proper engine breathing and combustion efficiency. The PROX 28.1226-1 delivers OEM-specification performance, ensuring reliable operation across demanding driving conditions. Whether you're rebuilding...09260666- SKU:
- 09260666
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- APPLICATION:
- EXHAUST
MSRP: $30.95Now: $25.00Was: $30.95 -
On Sale
PROX Intake Valve 28.1226-2
PROX
MSRP: $22.95Now: $17.00Was: $22.95A precision intake valve is critical to your engine's breathing efficiency and combustion reliability. The PROX 28.1226-2 delivers OEM-specification performance without compromise, ensuring consistent valve sealing and optimal airflow across your...09260667- SKU:
- 09260667
- Availability:
- Ships Same Business Day
- Weight:
- 0.09 LBS
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- VALVE
- APPLICATION:
- INTAKE
- UNITS:
- EACH
MSRP: $22.95Now: $17.00Was: $22.95 -
On Sale
PROX Intake Valve 28.1227-2
PROX
MSRP: $22.95Now: $17.00Was: $22.95Intake valve performance directly impacts combustion efficiency and engine responsiveness—compromised valve integrity leads to poor sealing, lost compression, and reduced power output. The PROX 28.1227-2 is engineered to OEM specifications, ensuring...09260669- SKU:
- 09260669
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- RIDING STYLE:
- OFF-ROAD
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- APPLICATION:
- INTAKE
- UNITS:
- EACH
MSRP: $22.95Now: $17.00Was: $22.95 -
On Sale
PROX Exhaust Valve 28.1323-1
PROX
MSRP: $30.95Now: $25.00Was: $30.95A precision exhaust valve is critical to maintaining proper engine breathing and combustion efficiency—without it, you're looking at compromised performance, increased emissions, and potential engine damage. The PROX 28.1323-1 is engineered to OEM...09260670- SKU:
- 09260670
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- VALVE
- UNITS:
- EACH
MSRP: $30.95Now: $25.00Was: $30.95 -
On Sale
PROX Intake Valve 28.1323-2
PROX
MSRP: $22.95Now: $17.00Was: $22.95The PROX Intake Valve 28.1323-2 is engineered to restore optimal valve sealing and combustion efficiency in high-demand engine applications. Precision-manufactured to OEM specifications, this valve ensures consistent performance and longevity under...09260671- SKU:
- 09260671
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- UNITS:
- EACH
MSRP: $22.95Now: $17.00Was: $22.95 -
On Sale
PROX Exhaust Valve 28.1338-1
PROX
MSRP: $39.95Now: $34.00Was: $39.95Maintaining precise valve operation is critical to engine reliability and performance, especially in high-stress racing applications. The PROX Exhaust Valve 28.1338-1 delivers OEM-matched specifications with the manufacturing precision required to...09260672- SKU:
- 09260672
- Availability:
- Ships Same Business Day
- Weight:
- 0.07 LBS
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- UNITS:
- EACH
- APPLICATION:
- EXHAUST
- RIDING STYLE:
- OFF-ROAD
MSRP: $39.95Now: $34.00Was: $39.95 -
On Sale
PROX Exhaust Valve 28.1381-1
PROX
MSRP: $30.95Now: $25.00Was: $30.95A precision exhaust valve is critical to maintaining optimal engine breathing and combustion efficiency—especially in high-performance applications where valve integrity directly impacts reliability and power output. The PROX 28.1381-1 meets OEM...09260675- SKU:
- 09260675
- Availability:
- Ships Same Business Day
- Weight:
- 0.08 LBS
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- PRODUCT NAME:
- VALVE
- APPLICATION:
- EXHAUST
MSRP: $30.95Now: $25.00Was: $30.95 -
On Sale
PROX Intake Valve 28.1381-2
PROX
MSRP: $22.95Now: $17.00Was: $22.95A properly functioning intake valve is critical to your engine's breathing efficiency and power delivery. The PROX 28.1381-2 is precision-engineered to OEM specifications, ensuring reliable sealing and consistent performance across combustion cycles...09260676- SKU:
- 09260676
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- APPLICATION:
- INTAKE
- UNITS:
- EACH
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- OFF-ROAD
MSRP: $22.95Now: $17.00Was: $22.95 -
PROX Exhaust Valve 28.2200-1
PROX
$25.95A precision exhaust valve is critical to your engine's breathing efficiency and power delivery—especially in high-performance applications where stock components fall short. The PROX 28.2200-1 is engineered to OEM specifications with the tolerances and...09260678- SKU:
- 09260678
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- VALVE
- UNITS:
- EACH
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
$25.95 -
PROX Intake Valve 28.2200-2
PROX
$17.95A precision intake valve is fundamental to your engine's breathing efficiency and combustion reliability. The PROX 28.2200-2 is manufactured to OEM specifications, ensuring consistent performance and longevity whether you're rebuilding a stock engine or...09260679- SKU:
- 09260679
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
$17.95 -
PROX Intake Valve 28.6520-2
PROX
$35.95A quality intake valve is fundamental to your engine's breathing efficiency and overall performance. The PROX 28.6520-2 is engineered to OEM specifications, ensuring reliable operation and proper sealing under all combustion cycles. Whether you're...09260689- SKU:
- 09260689
- Availability:
- Ships Same Business Day
- Weight:
- 0.12 LBS
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
$35.95 -
PROX Valve and Spring Kit 28.SES2402-1
PROX
$155.95If you're running high-RPM applications or pushing your engine beyond stock parameters, OEM valve and spring assemblies become your limiting factor. The PROX 28.SES2402-1 kit replaces weak factory components with nitrided steel valves and premium chrome...09261455- SKU:
- 09261455
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- SPRING KIT
- APPLICATION:
- EXHAUST
- TYPE:
- VALVE
$155.95 -
PROX Valve and Spring Kit 28.SES3338-1
PROX
$155.95If you're running your engine hard at high RPM, stock valve springs simply don't have the strength to keep up—resulting in valve float, lost power, and potential catastrophic failure. The PROX Valve and Spring Kit 28.SES3338-1 replaces those weak OEM...09261456- SKU:
- 09261456
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- UNITS:
- KIT
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- SPRING KIT
- TYPE:
- VALVE
$155.95 -
PROX Valve and Spring Kit 28.SIS1336-2
PROX
$155.95If you're pushing your engine to the limit, factory valve springs and valves will hold you back—they're simply not engineered for sustained high-RPM loads or the thermal stress of performance driving. The PROX 28.SIS1336-2 Kit replaces those weak links...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
$155.95 -
PROX Valve and Spring Kit 28.SIS1337-2
PROX
$149.95If you're running high-RPM applications or pushing your engine beyond stock parameters, OEM valve springs and valves become a limiting factor. The PROX 28.SIS1337-2 kit replaces both with nitrided steel valves and premium chrome vanadium springs...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 Valve and Spring Kit 28.SIS4335-2
PROX
$155.95If you're pushing your engine to its limits, OEM valves and springs become your limiting factor. The PROX 28.SIS4335-2 Kit replaces them with nitrided steel valves and premium chrome vanadium springs engineered to handle extreme RPMs and sustained...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
$155.95
