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
-
BOYESEN Clutch Cover - Gold - KTM/Husqvarna CC-44CB
BOYESEN
$95.95If you're serious about reducing unsprung weight and shaving precious grams off your KTM or Husqvarna, a lightweight factory clutch cover is non-negotiable. The BOYESEN CC-44CB delivers race-proven durability without the mass penalty, letting your...09401457- SKU:
- 09401457
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
- COLOR/FINISH:
- POWDER-COATED
- MODEL:
- FACTORY RACING
- TYPE:
- CLUTCH
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
- RIDING STYLE:
- STREET
$95.95Qty in Cart: 0Quantity:Price:$95.95Subtotal: -
BOYESEN Clutch Cover - Black - KTM/Husqvarna CC-41AB
BOYESEN
$95.95A lightweight clutch cover reduces unsprung mass and heat retention while delivering the durability required for competitive racing and trail abuse. The Boyesen CC-41AB features precision engineering with a leak-free design that won't compromise engine...09401453- SKU:
- 09401453
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- COLOR/FINISH:
- BLACK
- COLOR/FINISH:
- POWDER-COATED
- MODEL:
- FACTORY RACING
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
- RIDING STYLE:
- STREET
$95.95 -
BOYESEN Ignition Cover - Orange - KTM SC-41CO
BOYESEN
$97.95Stock ignition covers are vulnerable to dirt, water, and premature wear—especially in demanding riding conditions. The Boyesen SC-41CO Factory Ignition Cover is cast from high-grade aluminum to provide reliable protection while maintaining a lightweight...09401447- SKU:
- 09401447
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- COLOR/FINISH:
- ORANGE
- COLOR/FINISH:
- POWDER-COATED
- MATERIAL:
- ALUMINUM
- MODEL:
- FACTORY RACING
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- IGNITION
$97.95 -
BOYESEN Ignition Cover - Gold - KTM/Husqvarna SC-41CM
BOYESEN
$87.95Your engine's internals face constant threats from dust, moisture, and debris—especially in trail and off-road conditions. The BOYESEN Ignition Cover replaces the factory plastic alternative with a precision-cast aluminum design that seals reliably and...09401446- SKU:
- 09401446
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- COLOR/FINISH:
- MAGNESIUM
- COLOR/FINISH:
- POWDER-COATED
- MATERIAL:
- ALUMINUM
- MODEL:
- FACTORY RACING
- PRODUCT NAME:
- COVER
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- IGNITION
- UNITS:
- EACH
$87.95 -
BOYESEN Ignition Cover - Black - KTM/Husqvarna SC-41CB
BOYESEN
$87.95The stock ignition cover on your KTM or Husqvarna is vulnerable to mud, water, and debris—exactly what can compromise engine reliability during aggressive riding. The BOYESEN Factory Ignition Cover replaces that weak point with a precision-cast aluminum...09401445- SKU:
- 09401445
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- IGNITION
- COLOR/FINISH:
- POWDER-COATED
- MATERIAL:
- ALUMINUM
- MODEL:
- FACTORY RACING
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
$87.95Qty in Cart: 0Quantity:Price:$87.95Subtotal: -
BOYESEN Clutch Cover - Gold - Yamaha CC-37AM
BOYESEN
$95.95A clutch cover does more than protect—it's a visible statement of your commitment to quality and performance. The BOYESEN Clutch Cover combines lightweight construction with a factory-grade fit that eliminates leaks and looks sharp on the track or trail...09401371- SKU:
- 09401371
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
- COLOR/FINISH:
- MAGNESIUM
- COLOR/FINISH:
- POWDER-COATED
- MODEL:
- FACTORY RACING
- TYPE:
- CLUTCH
$95.95Qty in Cart: 0Quantity:Price:$95.95Subtotal: -
BOYESEN Clutch Cover - Black - Yamaha CC-37AB
BOYESEN
$95.95A clutch cover does more than protect—it sets the tone for your bike's reliability and appearance. The BOYESEN Lightweight Factory Clutch Cover delivers race-proven durability with a precision-fitted design that eliminates leaks, so you can focus on...09401370- SKU:
- 09401370
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- MODEL:
- FACTORY RACING
- TYPE:
- CLUTCH
- COLOR/FINISH:
- POWDER-COATED
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
$95.95Qty in Cart: 0Quantity:Price:$95.95Subtotal: -
BOYESEN Impeller/Waterpump Cover - Magnesium WPK-38CM
BOYESEN
$219.95Engine temperatures spike under load, compromising reliability and power output. The BOYESEN Impeller/Waterpump Cover upgrades your cooling system's core efficiency by increasing coolant flow across the entire RPM range, keeping your engine running at...09401369- SKU:
- 09401369
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- BASE FINISH:
- POWDER-COATED
- UNITS:
- KIT
- COLOR/FINISH:
- MAGNESIUM
- MATERIAL:
- ALUMINUM
- TYPE:
- WATER PUMP
- COLOR/FINISH:
- POWDER-COATED
- MODEL:
- SUPERCOOLER
- PRODUCT NAME:
- COVER AND IMPELLER KIT
- RIDING STYLE:
- OFF-ROAD
$219.95 -
BOYESEN Impeller/Waterpump Cover - Black WPK-38CB
BOYESEN
$219.95Engine cooling efficiency directly impacts performance, reliability, and longevity—especially under sustained high-RPM operation. The BOYESEN WPK-38CB water pump cover and impeller upgrade increases coolant flow across your entire RPM range, keeping...09401368- SKU:
- 09401368
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- BASE COLOR:
- BLACK
- MODEL:
- SUPERCOOLER
- TYPE:
- WATER PUMP
- BASE FINISH:
- POWDER-COATED
- MATERIAL:
- ALUMINUM
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COLOR/FINISH:
- POWDER-COATED
- PRODUCT NAME:
- COVER AND IMPELLER KIT
$219.95Qty in Cart: 0Quantity:Price:$219.95Subtotal: -
BOYESEN Impeller/Waterpump Cover - Black WPK-37AB
BOYESEN
$219.95Engine temperature stability directly impacts performance and longevity—especially under sustained high-RPM operation. The BOYESEN WPK-37AB water pump cover and impeller assembly increases coolant flow across the entire RPM band, keeping combustion...09401366- SKU:
- 09401366
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- BASE FINISH:
- POWDER-COATED
- UNITS:
- KIT
- COLOR/FINISH:
- BLACK
- COLOR/FINISH:
- POWDER-COATED
- MODEL:
- SUPERCOOLER
- PRODUCT NAME:
- COVER AND IMPELLER KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- WATER PUMP
- BASE COLOR:
- BLACK
- MATERIAL:
- ALUMINUM
$219.95Qty in Cart: 0Quantity:Price:$219.95Subtotal: -
BOYESEN Impeller/Waterpump Cover - Orange WPK-45O
BOYESEN
$199.95Engine coolant flow directly impacts operating temperature stability and component longevity—inadequate cooling creates hot spots that accelerate wear on gaskets, seals, and bearings. The Boyesen WPK-45O water pump cover and impeller upgrade increases...09401365- SKU:
- 09401365
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- TYPE:
- WATER PUMP
- COLOR/FINISH:
- ORANGE
- COLOR/FINISH:
- POWDER-COATED
- MODEL:
- SUPERCOOLER
- PRODUCT NAME:
- COVER AND IMPELLER KIT
- BASE FINISH:
- POWDER-COATED
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BASE COLOR:
- ORANGE
- MATERIAL:
- ALUMINUM
$199.95Qty in Cart: 0Quantity:Price:$199.95Subtotal: -
BOYESEN Impeller/Waterpump Cover - Magnesium WPK-45M
BOYESEN
$194.95Engine cooling efficiency directly impacts performance, reliability, and longevity—especially under sustained high-RPM operation. The Boyesen WPK-45M delivers increased coolant flow across the entire RPM range, maintaining optimal operating temperatures...09401364- SKU:
- 09401364
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COLOR/FINISH:
- POWDER-COATED
- PRODUCT NAME:
- COVER AND IMPELLER KIT
- MODEL:
- SUPERCOOLER
- TYPE:
- WATER PUMP
- BASE FINISH:
- POWDER-COATED
- COLOR/FINISH:
- MAGNESIUM
- MATERIAL:
- ALUMINUM
$194.95Qty in Cart: 0Quantity:Price:$194.95Subtotal: -
BOYESEN Impeller/Waterpump Cover - Black WPK-45B
BOYESEN
$194.95Engine cooling efficiency directly impacts performance, reliability, and longevity—especially under high-RPM conditions. The BOYESEN WPK-45B water pump cover and impeller combo increases coolant flow across the entire RPM range, allowing your engine to...09401363- SKU:
- 09401363
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BASE FINISH:
- POWDER-COATED
- MATERIAL:
- ALUMINUM
- TYPE:
- WATER PUMP
- BASE COLOR:
- BLACK
- MODEL:
- SUPERCOOLER
- COLOR/FINISH:
- POWDER-COATED
- PRODUCT NAME:
- COVER AND IMPELLER KIT
$194.95Qty in Cart: 0Quantity:Price:$194.95Subtotal: -
BOYESEN Clutch Cover - Gold - KTM/Husaberg CC-45M
BOYESEN
$95.95A factory-lightweight clutch cover cuts parasitic weight without sacrificing durability—critical when lap times are measured in hundredths. The individually surfaced design guarantees a leak-free fit straight out of the box, while the powder-coated...09401264- SKU:
- 09401264
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
- COLOR/FINISH:
- MAGNESIUM
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- COVER
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- TYPE:
- CLUTCH
- COLOR/FINISH:
- POWDER-COATED
- MODEL:
- FACTORY RACING
$95.95Qty in Cart: 0Quantity:Price:$95.95Subtotal: -
BOYESEN Clutch Cover - Black - KTM/Husaberg CC-45B
BOYESEN
$95.95A lightweight clutch cover isn't just about aesthetics—it's about reducing unsprung weight and minimizing heat retention in high-demand racing conditions. The Boyesen CC-45B is individually surfaced for a precision fit that eliminates the leak points...09401263- SKU:
- 09401263
- Availability:
- Ships Same Business Day
- Weight:
- 0.86 LBS
- PRODUCT NAME:
- COVER
- RIDING STYLE:
- STREET
- UNITS:
- EACH
- COLOR/FINISH:
- BLACK
- COLOR/FINISH:
- POWDER-COATED
- MODEL:
- FACTORY RACING
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
$95.95Qty in Cart: 0Quantity:Price:$95.95Subtotal: -
BOYESEN Impeller/Waterpump Cover - Orange WPK-44O
BOYESEN
$199.95Engine temperatures spike under load, robbing you of reliability and consistent performance—especially critical in racing applications where thermal management directly impacts horsepower delivery. The BOYESEN Impeller/Waterpump Cover upgrades your...09401236- SKU:
- 09401236
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- COLOR/FINISH:
- ORANGE
- COLOR/FINISH:
- POWDER-COATED
- PRODUCT NAME:
- COVER AND IMPELLER KIT
- MODEL:
- SUPERCOOLER
- TYPE:
- WATER PUMP
- BASE COLOR:
- ORANGE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BASE FINISH:
- POWDER-COATED
- MATERIAL:
- ALUMINUM
$199.95Qty in Cart: 0Quantity:Price:$199.95Subtotal: -
BOYESEN Impeller/Waterpump Cover - Magnesium WPK-44M
BOYESEN
$194.95Engine cooling efficiency directly impacts performance, reliability, and longevity—especially under sustained high-RPM operation. The BOYESEN WPK-44M water pump cover and impeller combo increases coolant circulation across your entire RPM range, keeping...09401235- SKU:
- 09401235
- Availability:
- Ships Same Business Day
- Weight:
- 0.38 LBS
- COLOR/FINISH:
- POWDER-COATED
- PRODUCT NAME:
- COVER AND IMPELLER KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- MODEL:
- SUPERCOOLER
- BASE FINISH:
- POWDER-COATED
- COLOR/FINISH:
- MAGNESIUM
- MATERIAL:
- ALUMINUM
- TYPE:
- WATER PUMP
$194.95Qty in Cart: 0Quantity:Price:$194.95Subtotal: -
BOYESEN Impeller/Waterpump Cover - Black WPK-44B
BOYESEN
$194.95Engine overheating under load is a performance killer—and stock cooling systems often can't keep pace with modified or high-RPM engines. The Boyesen WPK-44B water pump cover and impeller upgrade increases coolant flow across the entire RPM range,...09401234- SKU:
- 09401234
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- BASE COLOR:
- BLACK
- COLOR/FINISH:
- POWDER-COATED
- MATERIAL:
- ALUMINUM
- MODEL:
- SUPERCOOLER
- PRODUCT NAME:
- COVER AND IMPELLER KIT
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
- BASE FINISH:
- POWDER-COATED
- TYPE:
- WATER PUMP
- UNITS:
- KIT
$194.95Qty in Cart: 0Quantity:Price:$194.95Subtotal: -
BOYESEN Clutch Cover - Orange - KTM CC-44AO
BOYESEN
$105.95A lightweight clutch cover is essential for reducing rotating mass and improving engine responsiveness, especially in competitive racing environments where every gram matters. The BOYESEN CC-44AO delivers factory-grade protection without the weight...09401233- SKU:
- 09401233
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
- COLOR/FINISH:
- ORANGE
- COLOR/FINISH:
- POWDER-COATED
- MODEL:
- FACTORY RACING
- RIDING STYLE:
- STREET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
$105.95 -
BOYESEN Clutch Cover - Black - KTM CC-44AB
BOYESEN
$95.95A clutch cover isn't just cosmetic—it's your first line of defense against impact, contamination, and heat damage. The BOYESEN Lightweight Clutch Cover delivers race-proven protection without the weight penalty, featuring precision engineering that...09401231- SKU:
- 09401231
- Availability:
- Ships Same Business Day
- Weight:
- 0.88 LBS
- PRODUCT NAME:
- COVER
- UNITS:
- EACH
- COLOR/FINISH:
- POWDER-COATED
- RIDING STYLE:
- STREET
- COLOR/FINISH:
- BLACK
- MODEL:
- FACTORY RACING
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CLUTCH
$95.95
