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!
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- Price
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On Sale
Wossner Piston Ring 68mm for 1992-1998 Yamaha YZ250 RSB6800
WOSSNER
MSRP: $18.50Now: $17.58Was: $18.50A worn or damaged piston ring directly compromises compression, fuel efficiency, and power delivery in your YZ250—making replacement critical for both trail and competition use. The Wossner RSB6800...09120731- SKU:
- 09120731
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
MSRP: $18.50Now: $17.58Was: $18.50Qty in Cart: 0Quantity:Price:MSRP: $18.50Now: $17.58Was: $18.50Subtotal: -
On Sale
Wossner Piston Ring 72.50mm for 1999-2006 Polaris 500 Classic RSB7250
WOSSNER
MSRP: $18.50Now: $17.58Was: $18.50Worn or damaged piston rings are a direct threat to engine compression, power output, and fuel efficiency—especially critical in 2-stroke engines where ring sealing directly impacts performance. The...09120736- SKU:
- 09120736
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
MSRP: $18.50Now: $17.58Was: $18.50 -
On Sale
Wossner Universal Small End Bearing 16 mm x 20 mm x 19.5 mm N1013
WOSSNER
MSRP: $18.50Now: $17.58Was: $18.50Small-end bearing wear is one of the most common failure points in high-performance engine builds, leading to catastrophic rod failure if left unchecked. The Wossner N1013 is a precision needle...09240452- SKU:
- 09240452
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
MSRP: $18.50Now: $17.58Was: $18.50 -
VERTEX Engine Rebuild Kit - KTM 250 SXF/CXF WR101-160
VERTEX
$1,315.95A complete engine rebuild demands precision components that restore your KTM 250 SXF/CXF to factory specifications—and this VERTEX kit delivers exactly that. Rather than sourcing individual...09031261- SKU:
- 09031261
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
$1,315.95Qty in Cart: 0Quantity:Price:$1,315.95Subtotal: -
VERTEX Engine Rebuild Kit - KTM XC/XC-W 250 | Husqvarna TE250 WR101-091
VERTEX
$1,064.65When your KTM XC/XC-W 250 or Husqvarna TE250 engine reaches the end of its service life, a quality rebuild kit saves time and eliminates guesswork—you get every critical component in one box instead...09031066- SKU:
- 09031066
- Availability:
- Ships Same Business Day
- Weight:
- 15.20 LBS
$1,064.65 -
On Sale
Wossner Piston Ring Set 97.00mm Yamaha YZ450F 2020-2022 970XSY-3
WOSSNER
MSRP: $41.50Now: $39.43Was: $41.50Worn or damaged piston rings compromise combustion efficiency and increase blow-by, robbing your YZ450F of power and responsiveness. This Wossner ring set restores proper cylinder sealing with...09120689- SKU:
- 09120689
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
MSRP: $41.50Now: $39.43Was: $41.50Qty in Cart: 0Quantity:Price:MSRP: $41.50Now: $39.43Was: $41.50Subtotal: -
MOOSE OFFROAD Cylinder - 66.40 mm - Yamaha MSE20009
MOOSE OFFROAD
$597.95A worn or damaged cylinder compromises ring seal, increases blowby, and degrades power output—issues that ripple through your entire engine. This MOOSE OFFROAD cylinder restores your Yamaha to OEM...09311074- SKU:
- 09311074
- Availability:
- Ships Same Business Day
- Weight:
- 6.15 LBS
$597.95 -
HOT RODS Crankshaft - OEM Stroke - Polaris HR00046
HOT RODS
$1,104.95If you're running a Polaris engine that demands reliability on the track or trail, a properly balanced crankshaft is non-negotiable—it's the foundation that keeps your entire rotating assembly in...09210888- SKU:
- 09210888
- Availability:
- Ships Same Business Day
- Weight:
- 19.65 LBS
$1,104.95 -
On Sale
ATHENA Water Pump Gasket Kit - Yamaha P400485475014
ATHENA
MSRP: $57.95Now: $49.00Was: $57.95A worn or degraded water pump gasket kit compromises your cooling system's integrity, leading to coolant leaks, overheating, and potential engine damage. The ATHENA Water Pump Gasket Kit for Yamaha...09347194- SKU:
- 09347194
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
MSRP: $57.95Now: $49.00Was: $57.95 -
On Sale
KIBBLEWHITE Spring Kit 30-33600
KIBBLEWHITE
MSRP: $227.93Now: $191.73Was: $227.93If you're running boost or pushing your engine to its limits, valvetrain control becomes non-negotiable. The KIBBLEWHITE Spring Kit 30-33600 delivers the spring rates and component durability needed...09263377- SKU:
- 09263377
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
MSRP: $227.93Now: $191.73Was: $227.93 -
On Sale
KIBBLEWHITE Valve Kit - Intake 30-34000
KIBBLEWHITE
MSRP: $196.98Now: $165.68Was: $196.98A properly functioning intake valve system is fundamental to engine reliability and performance—worn or substandard valves compromise compression, increase blowby, and accelerate wear on your entire...09263378- SKU:
- 09263378
- Availability:
- Ships Same Business Day
- Weight:
- 0.70 LBS
MSRP: $196.98Now: $165.68Was: $196.98 -
On Sale
KIBBLEWHITE Valve - Intake - Black Diamond* 30-33612
KIBBLEWHITE
MSRP: $37.55Now: $33.80Was: $37.55Intake valve performance directly impacts combustion efficiency and engine reliability—particularly under high-RPM racing conditions where standard valves falter. Kibblewhite's Black Diamond valves...09263379- SKU:
- 09263379
- Availability:
- Ships Same Business Day
- Weight:
- 0.20 LBS
MSRP: $37.55Now: $33.80Was: $37.55 -
On Sale
KIBBLEWHITE Valve - Exhaust - Black Diamond* 30-33616
KIBBLEWHITE
MSRP: $37.55Now: $33.80Was: $37.55If you're running high-RPM applications or pushing your engine to its limits, valve quality directly impacts reliability and longevity. The Kibblewhite Black Diamond Exhaust Valve delivers the...09263380- SKU:
- 09263380
- Availability:
- Ships Same Business Day
- Weight:
- 0.21 LBS
MSRP: $37.55Now: $33.80Was: $37.55 -
On Sale
KIBBLEWHITE Valve Guide - Intake - Standard 30-33620
KIBBLEWHITE
MSRP: $24.89Now: $22.40Was: $24.89Valve guides are critical to maintaining proper valve seat geometry and preventing blow-by that kills performance and reliability. KIBBLEWHITE's Ampco-45 construction ensures superior heat...09263381- SKU:
- 09263381
- Availability:
- Ships Same Business Day
- Weight:
- 0.26 LBS
MSRP: $24.89Now: $22.40Was: $24.89 -
On Sale
KIBBLEWHITE Valve Guide - Intake - +0.010" 30-33629
KIBBLEWHITE
MSRP: $24.89Now: $22.40Was: $24.89Worn valve guides compromise cylinder head integrity and allow oil to seep into the combustion chamber, killing performance and reliability. KIBBLEWHITE intake valve guides are precision-engineered...09263382- SKU:
- 09263382
- Availability:
- Ships Same Business Day
- Weight:
- 0.26 LBS
MSRP: $24.89Now: $22.40Was: $24.89 -
On Sale
KIBBLEWHITE Valve Guide - Exhaust - Standard 30-33630
KIBBLEWHITE
MSRP: $24.89Now: $22.40Was: $24.89Exhaust valve guides experience extreme thermal cycling and abrasive wear—they're critical to maintaining valve sealing integrity and engine longevity. The KIBBLEWHITE Standard 30-33630 uses Ampco-45...09263383- SKU:
- 09263383
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
MSRP: $24.89Now: $22.40Was: $24.89 -
On Sale
KIBBLEWHITE Valve Guide - Exhaust - +0.010" 30-33639
KIBBLEWHITE
MSRP: $22.95Now: $20.66Was: $22.95Worn or damaged valve guides compromise cylinder head integrity and allow oil to seep into combustion chambers, reducing performance and increasing emissions. KIBBLEWHITE's +0.010" exhaust valve...09263384- SKU:
- 09263384
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
MSRP: $22.95Now: $20.66Was: $22.95 -
On Sale
KIBBLEWHITE Spring Kit 40-41600
KIBBLEWHITE
MSRP: $227.93Now: $191.73Was: $227.93If you're running a forced induction setup or high-lift cam profile, stock valve springs will cost you reliability and peak power. The KIBBLEWHITE Spring Kit 40-41600 delivers the valvetrain control...09263385- SKU:
- 09263385
- Availability:
- Ships Same Business Day
- Weight:
- 0.53 LBS
MSRP: $227.93Now: $191.73Was: $227.93 -
On Sale
KIBBLEWHITE Valve Kit - Intake 40-41650
KIBBLEWHITE
MSRP: $188.83Now: $151.76Was: $188.83Your engine's intake valves are constantly under extreme thermal and mechanical stress—worn or substandard valves will compromise combustion efficiency, increase friction losses, and accelerate wear...09263386- SKU:
- 09263386
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
MSRP: $188.83Now: $151.76Was: $188.83 -
On Sale
KIBBLEWHITE Valve - Intake - White Diamond 40-41612H
KIBBLEWHITE
MSRP: $35.22Now: $27.91Was: $35.22Kibblewhite's White Diamond intake valves are engineered for maximum durability and thermal stability in high-performance applications. Built from premium EV8 stainless steel or Inconel-751 and...09263387- SKU:
- 09263387
- Availability:
- Ships Same Business Day
- Weight:
- 0.07 LBS
MSRP: $35.22Now: $27.91Was: $35.22
