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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- Qty in Cart
- Quantity
- Price
- Subtotal
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MOOSE RACING Magnetic Drain Plug T14-1082S
MOOSE RACING
$17.95Engine wear doesn't announce itself—metal filings circulate silently through your oil until catastrophic damage occurs. The MOOSE RACING Magnetic Drain Plug T14-1082S captures ferrous particles before they cause bearing wear, ring scoring, or complete...09200191- SKU:
- 09200191
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- COLOR/FINISH:
- ANODIZED CLEAR
- FEATURES:
- MAGNETIC
- DIAMETER - THREAD SIZE METRIC:
- M8 X 1.25 X 33 MM
- PRODUCT NAME:
- PLUG
- UNITS:
- EACH
- COLOR/FINISH:
- SILVER
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- DRAIN
$17.95 -
MOOSE RACING Top End Gasket Kit - XR100 810221
MOOSE RACING
$24.85A top-end rebuild demands precision and reliability—this Moose Racing gasket kit delivers both at a fraction of OEM pricing. Whether you're replacing a worn piston or performing routine maintenance, you get every seal, gasket, and O-ring needed for a...M810221- SKU:
- M810221
- Availability:
- Ships Same Business Day
- Weight:
- 0.12 LBS
- TYPE:
- TOP END
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$24.85 -
MOOSE RACING Top End Gasket Kit - CR125R 810232
MOOSE RACING
$23.33A top-end rebuild demands precision gaskets and seals that won't fail under race conditions or repeated heat cycles. This Moose Racing kit eliminates the guesswork by including every component you need—valve seals, head gasket, base gasket, exhaust...M810232- SKU:
- M810232
- Availability:
- Ships Same Business Day
- Weight:
- 0.13 LBS
- TYPE:
- TOP END
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$23.33 -
MOOSE RACING Top End Gasket Kit - CR125R 810233
MOOSE RACING
$42.36When you're rebuilding a CR125R top end, gasket failure isn't an option—it compromises compression, invites oil leakage, and can sideline your bike mid-season. The MOOSE RACING Top End Gasket Kit eliminates guesswork by delivering every seal, O-ring, and...M810233- SKU:
- M810233
- Availability:
- Ships Same Business Day
- Weight:
- 0.13 LBS
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- TOP END
$42.36 -
MOOSE RACING Top End Gasket Kit - CR125 810235
MOOSE RACING
$37.29A top-end rebuild demands precision components that won't compromise reliability or performance. The MOOSE RACING Gasket Kit delivers OEM-quality seals at a fraction of the cost, giving you complete confidence when reassembling your CR125 after a piston...M810235- SKU:
- M810235
- Availability:
- Ships Same Business Day
- Weight:
- 0.13 LBS
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
$37.29 -
MOOSE RACING Top End Gasket Kit - CR250 810251
MOOSE RACING
$17.46A top-end rebuild demands precision gaskets and seals that match OEM specifications without the premium OEM price tag. The MOOSE RACING gasket kit delivers complete coverage for CR250 rebuilds—every gasket, O-ring, and seal you need in one package,...M810251- SKU:
- M810251
- Availability:
- Ships Same Business Day
- Weight:
- 0.13 LBS
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
$17.46 -
MOOSE RACING Top End Gasket Kit - CR250R 810252
MOOSE RACING
$21.90When you're rebuilding a CR250R top end, gasket failure isn't an option. This Moose Racing kit eliminates the guesswork by delivering every seal, O-ring, and gasket you need in one package—all manufactured to precise tolerances and backed by proven...M810252- SKU:
- M810252
- Availability:
- Ships Same Business Day
- Weight:
- 0.13 LBS
- PRODUCT NAME:
- GASKET
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- TOP END
- UNITS:
- KIT
$21.90 -
LA Sleeve Cylinder Sleeve for Suzuki LT250R 1988-1992 FL5064
LA SLEEVE
$148.95When cylinder wear compromises compression and power delivery, a quality sleeve restoration becomes essential for reliable performance. The LA SLEEVE FL5064 restores your Suzuki LT250R's original bore dimensions, eliminating blow-by and revitalizing...FL5064- SKU:
- FL5064
- Availability:
- Ships Same Business Day
- Weight:
- 2.19 LBS
- BORE SIZE METRIC:
- 67.00 MM
- COLOR/FINISH:
- ALUMINUM
- PRODUCT NAME:
- CYLINDER SLEEVE
- TYPE:
- CS
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- CYLINDER BORE COATING:
- CHROME-MOLY ALLOY
$148.95 -
LA Sleeve Cylinder Sleeve 1989-1990 Suzuki RM250 RMX250 67mm Bore FL5093
LA SLEEVE
$153.95If you're rebuilding a 1989-1990 RM250 or RMX250, a worn cylinder is the bottleneck preventing peak performance. The LA SLEEVE FL5093 restores compression and sealing integrity, giving you the reliability needed for serious riding or racing. This...FL5093- SKU:
- FL5093
- Availability:
- Ships Same Business Day
- Weight:
- 1.31 LBS
- COLOR/FINISH:
- CHROME
- UNITS:
- EACH
- BORE SIZE METRIC:
- 67.00 MM
- CYLINDER BORE COATING:
- CHROME-MOLY ALLOY
- TYPE:
- AC
- PRODUCT NAME:
- CYLINDER SLEEVE
- RIDING STYLE:
- OFF-ROAD
$153.95 -
L.A. Sleeve Cylinder Sleeve 47.50mm Bore Suzuki RM80 1991-2001 FL5140
LA SLEEVE
$117.95A worn cylinder sleeve compromises compression, increases blow-by, and robs your RM80 of power and efficiency. The L.A. Sleeve FL5140 restores your engine to factory specifications with a precision-engineered replacement that handles the demands of trail...FL5140- SKU:
- FL5140
- Availability:
- Ships Same Business Day
- Weight:
- 0.88 LBS
- BORE SIZE METRIC:
- 47.50 MM
- PRODUCT NAME:
- CYLINDER SLEEVE
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- CS
- COLOR/FINISH:
- CHROME
- UNITS:
- EACH
- CYLINDER BORE COATING:
- CHROME-MOLY ALLOY
$117.95 -
CYCLE CRAFT Friction Washer 39-21252
CYCLE CRAFT
$37.23Kits contain main spring, cover plate, throw-out springs, pawls, D-washers, rope and pull handle, Parts fit all models ATC185/200; will also fit 90/110 models if different rope is used, Fit models ATC185 80, ATC185S 81-83, ATC200 81-83, ATC200E Big Red...21252- SKU:
- 21252
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- PRODUCT NAME:
- WASHER
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- TYPE:
- STARTER
$37.23 -
CYCLE CRAFT Friction Plate 39-21253
CYCLE CRAFT
$14.31Kits contain main spring, cover plate, throw-out springs, pawls, D-washers, rope and pull handle, Parts fit all models ATC185/200; will also fit 90/110 models if different rope is used, Fit models ATC185 80, ATC185S 81-83, ATC200 81-83, ATC200E Big Red...21253- SKU:
- 21253
- Availability:
- Ships Same Business Day
- Weight:
- 0.13 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- PRODUCT NAME:
- COVER PLATE
- TYPE:
- STARTER
$14.31 -
Cylinder Works Standard Bore Cylinder KTM 50 SX 2009-2023 CW50012
CYLINDER WORKS
$434.95When your KTM 50 SX's cylinder shows signs of wear—scored walls, compression loss, or damaged plating—a quality replacement is essential to restore engine integrity and performance. The Cylinder Works Standard Bore cylinder delivers OEM-equivalent...09311022- SKU:
- 09311022
- Availability:
- Ships Same Business Day
- Weight:
- 2.61 LBS
- UNITS:
- EACH
- CYLINDER DIAMETER METRIC:
- 39.50 MM
- PRODUCT NAME:
- CYLINDER
- RIDING STYLE:
- OFF-ROAD
- CYLINDER DIAMETER:
- 39,50 MM
- ENGINE TYPE:
- 2-CYCLE
- STYLE:
- STANDARD
$434.95 -
Cylinder Works Yamaha WR250F 2018-2019 High Compression Cylinder Kit 20010-K02HC
CYLINDER WORKS
$750.95If you're running a WR250F, factory displacement limits your peak performance and torque delivery. The Cylinder Works high-compression big bore kit unlocks additional cubic centimeters and compression ratio, delivering measurable power gains while...09310709- SKU:
- 09310709
- Availability:
- Ships Same Business Day
- Weight:
- 3.20 LBS
- CYLINDER DIAMETER METRIC:
- 77.00 MM
- CYLINDER DIAMETER:
- 77,00 MM
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE SIZE METRIC:
- 77.00 MM
- COMPRESSION RATIO IMPERIAL:
- 14.2:1
- STYLE:
- STANDARD
- ENGINE TYPE:
- 4-CYCLE
$750.95 -
Cylinder Works Standard Bore Cylinder Kit for 2007-2008 Honda CRF450R 10002-K02
CYLINDER WORKS
$651.95Stock CRF450R cylinders wear, lose compression, and rob you of the power you've built. The Cylinder Works Standard Bore Kit restores your engine to original specifications while delivering the durability and reliability you need for consistent track...09310839- SKU:
- 09310839
- Availability:
- Ships Same Business Day
- Weight:
- 4.71 LBS
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER:
- 96,00 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- CYLINDER DIAMETER METRIC:
- 96.00 MM
- OVERBORE METRIC:
- STANDARD
- STYLE:
- STANDARD
- DISPLACEMENT:
- 449 CC
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- COMPRESSION RATIO IMPERIAL:
- 12.1:1
$651.95 -
Cylinder Works Big Bore Cylinder Kit for Honda CRF450R 2007-2019 10002-K02HC
CYLINDER WORKS
$690.95If you're running a Honda CRF450R, factory displacement limits your peak power output when you're pushing hard on the track or trail. The Cylinder Works Big Bore Kit removes that constraint with a straightforward bolt-on upgrade that delivers measurable...09310841- SKU:
- 09310841
- Availability:
- Ships Same Business Day
- Weight:
- 4.71 LBS
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER:
- 96,00 MM
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- DISPLACEMENT:
- 449 CC
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- CYLINDER DIAMETER METRIC:
- 96.00 MM
- RIDING STYLE:
- OFF-ROAD
$690.95 -
Cylinder Works Standard Bore Cylinder Kit Arctic Cat 400 DVX 2004-2008 40001-K02
CYLINDER WORKS
$717.95If your Arctic Cat 400 DVX is experiencing bore wear or you're looking to restore factory performance, the Cylinder Works Standard Bore Cylinder Kit delivers a complete, bolt-on solution without the downtime of machine work or re-plating. This matched...09310842- SKU:
- 09310842
- Availability:
- Ships Same Business Day
- Weight:
- 5.16 LBS
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- STYLE:
- STANDARD
- CYLINDER DIAMETER:
- 90,00 MM
- PRODUCT NAME:
- CYLINDER KIT
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 11.3:1
- DISPLACEMENT:
- 400 CC
- CYLINDER DIAMETER METRIC:
- 90.00 MM
- ENGINE TYPE:
- 4-CYCLE
- RIDING STYLE:
- ATV
$717.95 -
Cylinder Works Standard Bore High Compression Cylinder Kit for 2004-2008 Arctic Cat 400 DVX 40001-K02HC
CYLINDER WORKS
$716.95If you're running a 2004-2008 Arctic Cat 400 DVX and want measurable gains in displacement and compression ratio without extensive machine work, this Cylinder Works kit delivers a bolt-on solution. The matched Vertex pistons and Nickel Silicon Carbide...09310843- SKU:
- 09310843
- Availability:
- Ships Same Business Day
- Weight:
- 5.16 LBS
- DISPLACEMENT:
- 400 CC
- ENGINE TYPE:
- 4-CYCLE
- CYLINDER DIAMETER METRIC:
- 90.00 MM
- RIDING STYLE:
- ATV
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER:
- 90,00 MM
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- UNITS:
- KIT
$716.95 -
Cylinder Works Standard Bore Cylinder Kit for 2018-2019 Honda CRF250R CW10011K01
CYLINDER WORKS
$622.95If you're running a 2018-2019 CRF250R, this cylinder kit delivers a direct path to increased displacement and responsive power without the downtime of custom machine work. The matched Vertex piston and Nickel Silicon Carbide plating work together to...09310845- SKU:
- 09310845
- Availability:
- Ships Same Business Day
- Weight:
- 3.46 LBS
- DISPLACEMENT:
- 249 CC
- ENGINE TYPE:
- 4-CYCLE
- CYLINDER DIAMETER:
- 79,00 MM
- STYLE:
- STANDARD
- COMPRESSION RATIO IMPERIAL:
- 13.9:1
- CYLINDER DIAMETER METRIC:
- 79.00 MM
- RIDING STYLE:
- OFF-ROAD
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- PRODUCT NAME:
- CYLINDER KIT
- UNITS:
- KIT
$622.95 -
Cylinder Works High Compression Cylinder Kit Honda CRF250R 2018-2019 CW10011K01HC
CYLINDER WORKS
$664.95The CRF250R demands more power to stay competitive on the track or trail, and the Cylinder Works High Compression Cylinder Kit delivers exactly that without requiring expensive machine work or downtime. This bolt-on big bore kit increases displacement...09310846- SKU:
- 09310846
- Availability:
- Ships Same Business Day
- Weight:
- 3.41 LBS
- DISPLACEMENT:
- 249 CC
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- STYLE:
- BIG BORE
- CYLINDER DIAMETER METRIC:
- 79.00 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 14.6:1
- CYLINDER DIAMETER:
- 79,00 MM
$664.95
