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-44CM
BOYESEN
$95.95A lightweight clutch cover that delivers the precision fit and durability expected on the track—without compromising on appearance. The individually surfaced design eliminates common leak points,...09401458- SKU:
- 09401458
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- COLOR/FINISH:
- MAGNESIUM
- RIDING STYLE:
- STREET
- MODEL:
- FACTORY RACING
- TYPE:
- CLUTCH
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- COLOR/FINISH:
- POWDER-COATED
- PRODUCT NAME:
- COVER
$95.95Qty in Cart: 0Quantity:Price:$95.95Subtotal: -
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...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
$95.95 -
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...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
$95.95Qty in Cart: 0Quantity:Price:$95.95Subtotal: -
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...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...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...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
$87.95 -
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...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...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...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
$219.95Qty in Cart: 0Quantity:Price:$219.95Subtotal: -
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...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
$219.95 -
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...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...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...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...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...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...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...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...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...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...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
