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
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On Sale
VINTCO Main Bearing and Seal Kit - Honda KMB005
VINTCO
MSRP: $49.95Now: $46.45Was: $49.95A proper crankshaft installation hinges on quality bearings and seals—cheap or worn components can lead to bearing failure, oil leaks, and catastrophic engine damage. The VINTCO Main Bearing and Seal...09240654- SKU:
- 09240654
- Availability:
- Ships Same Business Day
- Weight:
- 1.46 LBS
MSRP: $49.95Now: $46.45Was: $49.95Qty in Cart: 0Quantity:Price:MSRP: $49.95Now: $46.45Was: $49.95Subtotal: -
On Sale
VINTCO Main Bearing and Seal Kit - Honda KMB006
VINTCO
MSRP: $47.95Now: $44.59Was: $47.95Main bearing and seal failure compromises engine reliability and can lead to catastrophic damage if left unaddressed. The VINTCO KMB006 kit delivers OEM-spec components engineered for precise...09240655- SKU:
- 09240655
- Availability:
- Ships Same Business Day
- Weight:
- 1.46 LBS
MSRP: $47.95Now: $44.59Was: $47.95 -
On Sale
VINTCO Main Bearing and Seal Kit - Honda KMB034
VINTCO
MSRP: $54.95Now: $51.10Was: $54.95A quality crankshaft installation demands precision-matched bearings and seals that maintain proper clearances and prevent oil leakage under high RPM stress. The VINTCO KMB034 kit delivers OEM-grade...09240656- SKU:
- 09240656
- Availability:
- Ships Same Business Day
- Weight:
- 1.46 LBS
MSRP: $54.95Now: $51.10Was: $54.95 -
On Sale
VINTCO Main Bearing and Seal Kit - Honda KMB032
VINTCO
MSRP: $54.95Now: $51.10Was: $54.95A worn or improperly installed crankshaft bearing and seal assembly can lead to catastrophic engine failure, metal-on-metal contact, and catastrophic loss of oil pressure. The VINTCO KMB032 Main...09240657- SKU:
- 09240657
- Availability:
- Ships Same Business Day
- Weight:
- 1.46 LBS
MSRP: $54.95Now: $51.10Was: $54.95Qty in Cart: 0Quantity:Price:MSRP: $54.95Now: $51.10Was: $54.95Subtotal: -
On Sale
VINTCO Main Bearing and Seal Kit - Honda KMB031
VINTCO
MSRP: $44.95Now: $41.80Was: $44.95A failing crankshaft seal or worn main bearing will compromise engine reliability and performance—and catching these issues early requires a complete, quality bearing and seal kit. The VINTCO KMB031...09240658- SKU:
- 09240658
- Availability:
- Ships Same Business Day
- Weight:
- 0.91 LBS
MSRP: $44.95Now: $41.80Was: $44.95 -
On Sale
VINTCO Main Bearing and Seal Kit - Kawasaki KMB007
VINTCO
MSRP: $29.95Now: $27.85Was: $29.95A crankshaft rebuild demands precision and reliability—this kit delivers both with Japanese-manufactured bearings and seals engineered to Kawasaki specifications. Whether you're completing a full...09240659- SKU:
- 09240659
- Availability:
- Ships Same Business Day
- Weight:
- 0.71 LBS
MSRP: $29.95Now: $27.85Was: $29.95 -
On Sale
VINTCO Main Bearing and Seal Kit - Kawasaki KMB009
VINTCO
MSRP: $47.95Now: $44.59Was: $47.95A complete crankshaft installation requires precision-matched bearings and seals that can handle sustained high RPM loads without compromise. The VINTCO Main Bearing and Seal Kit delivers OEM-quality...09240660- SKU:
- 09240660
- Availability:
- Ships Same Business Day
- Weight:
- 1.16 LBS
MSRP: $47.95Now: $44.59Was: $47.95Qty in Cart: 0Quantity:Price:MSRP: $47.95Now: $44.59Was: $47.95Subtotal: -
On Sale
VINTCO Main Bearing and Seal Kit - Kawasaki KMB011
VINTCO
MSRP: $47.95Now: $44.59Was: $47.95A compromised crankshaft bearing or seal can silently degrade engine performance and lead to catastrophic failure. The VINTCO KMB011 Main Bearing and Seal Kit eliminates guesswork by providing...09240661- SKU:
- 09240661
- Availability:
- Ships Same Business Day
- Weight:
- 1.16 LBS
MSRP: $47.95Now: $44.59Was: $47.95 -
On Sale
VINTCO Main Bearing and Seal Kit - Kawasaki KMB010
VINTCO
MSRP: $47.95Now: $44.59Was: $47.95A worn crankshaft bearing or failing seal will compromise engine efficiency, increase operating temperatures, and accelerate internal wear—ultimately shortening your engine's lifespan. The VINTCO...09240662- SKU:
- 09240662
- Availability:
- Ships Same Business Day
- Weight:
- 1.16 LBS
MSRP: $47.95Now: $44.59Was: $47.95 -
On Sale
VINTCO Main Bearing and Seal Kit - Kawasaki KMB008
VINTCO
MSRP: $29.95Now: $27.85Was: $29.95A reliable crankshaft installation depends on precision-engineered bearings and seals that can withstand sustained load and RPM cycles. The VINTCO Main Bearing and Seal Kit supplies OEM-quality...09240663- SKU:
- 09240663
- Availability:
- Ships Same Business Day
- Weight:
- 0.76 LBS
MSRP: $29.95Now: $27.85Was: $29.95 -
On Sale
VINTCO Main Bearing and Seal Kit - Maico KMB028
VINTCO
MSRP: $109.95Now: $102.25Was: $109.95A worn or damaged main bearing and seal assembly compromises crankshaft stability, leading to excessive runout, oil leakage, and accelerated engine wear. The VINTCO KMB028 kit delivers a complete...09240664- SKU:
- 09240664
- Availability:
- Ships Same Business Day
- Weight:
- 1.46 LBS
MSRP: $109.95Now: $102.25Was: $109.95 -
On Sale
VINTCO Main Bearing and Seal Kit - Maico KMB026
VINTCO
MSRP: $69.95Now: $65.05Was: $69.95A quality crankshaft installation depends on precision-engineered bearings and seals that can handle sustained RPMs and load cycling without degradation. The VINTCO Main Bearing and Seal Kit for...09240665- SKU:
- 09240665
- Availability:
- Ships Same Business Day
- Weight:
- 1.54 LBS
MSRP: $69.95Now: $65.05Was: $69.95 -
On Sale
VINTCO Main Bearing and Seal Kit - Maico KMB027
VINTCO
MSRP: $79.95Now: $74.35Was: $79.95A properly sealed and supported crankshaft is foundational to engine reliability and longevity. This VINTCO Main Bearing and Seal Kit supplies OEM-quality Japanese bearings and seals engineered to...09240666- SKU:
- 09240666
- Availability:
- Ships Same Business Day
- Weight:
- 1.46 LBS
MSRP: $79.95Now: $74.35Was: $79.95 -
On Sale
VINTCO Main Bearing and Seal Kit - Suzuki KMB014
VINTCO
MSRP: $34.95Now: $32.50Was: $34.95A complete crankshaft installation demands precision-matched bearings and seals—any compromise here risks catastrophic engine failure and costly downtime. The VINTCO KMB014 Main Bearing and Seal Kit...09240667- SKU:
- 09240667
- Availability:
- Ships Same Business Day
- Weight:
- 0.96 LBS
MSRP: $34.95Now: $32.50Was: $34.95 -
On Sale
VINTCO Main Bearing and Seal Kit - Suzuki KMB015
VINTCO
MSRP: $29.95Now: $27.85Was: $29.95A quality main bearing and seal kit is fundamental to a reliable crankshaft assembly—it directly impacts engine longevity, oil retention, and overall performance stability. The VINTCO KMB015 delivers...09240668- SKU:
- 09240668
- Availability:
- Ships Same Business Day
- Weight:
- 0.81 LBS
MSRP: $29.95Now: $27.85Was: $29.95 -
On Sale
VINTCO Main Bearing and Seal Kit - Suzuki KMB016
VINTCO
MSRP: $29.95Now: $27.85Was: $29.95A proper crankshaft installation depends on quality main bearings and seals—failure here leads to catastrophic engine damage and costly rebuilds. The VINTCO KMB016 kit delivers OEM-spec components...09240669- SKU:
- 09240669
- Availability:
- Ships Same Business Day
- Weight:
- 0.81 LBS
MSRP: $29.95Now: $27.85Was: $29.95 -
On Sale
VINTCO Main Bearing and Seal Kit - Suzuki KMB022
VINTCO
MSRP: $44.95Now: $41.80Was: $44.95A complete crankshaft installation demands precision-matched bearings and seals—this kit eliminates the guesswork by bundling everything you need in one package. VINTCO's OEM-quality Japanese...09240672- SKU:
- 09240672
- Availability:
- Ships Same Business Day
- Weight:
- 1.76 LBS
MSRP: $44.95Now: $41.80Was: $44.95Qty in Cart: 0Quantity:Price:MSRP: $44.95Now: $41.80Was: $44.95Subtotal: -
On Sale
VINTCO Main Bearing and Seal Kit - Suzuki KMB017
VINTCO
MSRP: $32.95Now: $30.64Was: $32.95A compromised crankshaft bearing or seal will quickly degrade engine reliability and performance—making a quality bearing and seal kit essential for any serious engine rebuild. The VINTCO KMB017...09240673- SKU:
- 09240673
- Availability:
- Ships Same Business Day
- Weight:
- 0.81 LBS
MSRP: $32.95Now: $30.64Was: $32.95 -
On Sale
VINTCO Main Bearing and Seal Kit - Suzuki KMB020
VINTCO
MSRP: $61.95Now: $57.61Was: $61.95A worn or damaged crankshaft bearing and seal assembly compromises engine reliability, efficiency, and longevity—especially in high-performance applications where precision tolerances are critical...09240674- SKU:
- 09240674
- Availability:
- Ships Same Business Day
- Weight:
- 1.01 LBS
MSRP: $61.95Now: $57.61Was: $61.95 -
On Sale
VINTCO Main Bearing and Seal Kit - Suzuki KMB021
VINTCO
MSRP: $37.95Now: $35.29Was: $37.95Your Suzuki's crankshaft requires precise bearing clearances and reliable seals to maintain oil pressure and prevent catastrophic engine failure. This complete VINTCO kit eliminates the guesswork of...09240675- SKU:
- 09240675
- Availability:
- Ships Same Business Day
- Weight:
- 1.76 LBS
MSRP: $37.95Now: $35.29Was: $37.95
