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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CYLINDER WORKS Cylinder - Standard 10002
CYLINDER WORKS
$402.95OEM cylinder wear compromises ring seal integrity and increases blowby, robbing you of power and reliability. The CYLINDER WORKS Standard 10002 delivers a factory-fresh bore with the durability of nickel silicon carbide plating—all without the downtime...09310129- SKU:
- 09310129
- Availability:
- Ships Same Business Day
- Weight:
- 0.13 LBS
- DISPLACEMENT:
- 449 CC
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER
- COMPRESSION RATIO IMPERIAL:
- 12.1:1
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- UNITS:
- EACH
- CYLINDER DIAMETER:
- 96,00 MM
- RIDING STYLE:
- OFF-ROAD
- CYLINDER DIAMETER METRIC:
- 96.00 MM
- OVERBORE METRIC:
- STANDARD
- STYLE:
- STANDARD
$402.95 -
Cylinder Works Standard Bore Cylinder Kit for Yamaha YZ250F 2005-2007 20002-K02
CYLINDER WORKS
$395.95If you're running a 2005-2007 Yamaha YZ250F and want to restore or upgrade cylinder performance without machine shop downtime, the Cylinder Works Standard Bore Kit is your direct solution. The nickel silicon carbide plating significantly outlasts stock...09310131- SKU:
- 09310131
- Availability:
- Ships Same Business Day
- Weight:
- 2.90 LBS
- BORE SIZE METRIC:
- 77.00 MM
- STYLE:
- STANDARD
- ENGINE TYPE:
- 4-CYCLE
- CYLINDER DIAMETER METRIC:
- 77.00 MM
- UNITS:
- EACH
- CYLINDER DIAMETER:
- 77,00 MM
- PRODUCT NAME:
- CYLINDER
- RIDING STYLE:
- OFF-ROAD
$395.95 -
Cylinder Works Big Bore Kit Honda TRX450R 2004-2005 479cc 10.5:1 11003-K01
CYLINDER WORKS
$809.95A big bore upgrade is one of the most effective ways to unlock additional displacement and power from your TRX450R without compromising reliability. The Cylinder Works 479cc kit delivers a straightforward bolt-on solution that combines precision...09310133- SKU:
- 09310133
- Availability:
- Ships Same Business Day
- Weight:
- 4.47 LBS
- COMPRESSION RATIO IMPERIAL:
- 10.5:1
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER METRIC:
- 97.00 MM
- OVERBORE METRIC:
- +3.00 MM
- ENGINE TYPE:
- 4-CYCLE
- RIDING STYLE:
- ATV
- CYLINDER DIAMETER:
- 97,00 MM
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- DISPLACEMENT:
- 479 CC
- UNITS:
- KIT
$809.95 -
Cylinder Works Yamaha WR450F YFZ450R YZ450F 2007-2014 High Compression Cylinder Kit 20003-K01HC
CYLINDER WORKS
$788.95If you're running a 2007-2014 Yamaha WR450F, YFZ450R, or YZ450F, a worn or damaged cylinder directly compromises compression, throttle response, and overall engine reliability. The Cylinder Works High Compression Cylinder Kit restores—and improves...09310299- SKU:
- 09310299
- Availability:
- Ships Same Business Day
- Weight:
- 4.38 LBS
- COMPRESSION RATIO IMPERIAL:
- 13.5:1
- CYLINDER DIAMETER METRIC:
- 95.00 MM
- DISPLACEMENT:
- 449 CC
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- OFF-ROAD
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- UNITS:
- KIT
- CYLINDER DIAMETER:
- 95,00 MM
- STYLE:
- HIGH COMPRESSION
$788.95 -
Cylinder Works High Compression Cylinder Kit for Suzuki LT-R450 2006-2009 40002-K01HC
CYLINDER WORKS
$743.95If you're serious about extracting more power from your LT-R450, a high-compression cylinder kit is one of the most effective bolt-on upgrades available. This Cylinder Works kit delivers a straightforward path to increased displacement and compression...09310303- SKU:
- 09310303
- Availability:
- Ships Same Business Day
- Weight:
- 4.30 LBS
- COMPRESSION RATIO IMPERIAL:
- 13.0:1
- DISPLACEMENT:
- 449 CC
- ENGINE TYPE:
- 4-CYCLE
- STYLE:
- HIGH COMPRESSION
- CYLINDER DIAMETER:
- 95,50 MM
- RIDING STYLE:
- ATV
- UNITS:
- KIT
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER METRIC:
- 95.50 MM
- PRODUCT NAME:
- CYLINDER KIT
$743.95 -
Cylinder Works Big Bore Kit Yamaha YZ250F 2001-2013 21002-K01
CYLINDER WORKS
$836.95If you're running a YZ250F and want to unlock measurable gains in displacement and power output, a big bore kit is one of the most direct upgrades available. The Cylinder Works 21002-K01 delivers a complete, bolt-on solution that eliminates...09310121- SKU:
- 09310121
- Availability:
- Ships Same Business Day
- Weight:
- 3.37 LBS
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- DISPLACEMENT:
- 269 CC
- OVERBORE METRIC:
- +3.00 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- CYLINDER DIAMETER METRIC:
- 80.00 MM
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- CYLINDER DIAMETER:
- 80,00 MM
$836.95 -
CYLINDER WORKS Cylinder - Standard 30001
CYLINDER WORKS
$410.95A worn or damaged cylinder can severely limit your engine's efficiency and reliability on the track or in the shop. The CYLINDER WORKS Standard 30001 delivers a ready-to-install replacement that matches OEM specifications without requiring costly...09310130- SKU:
- 09310130
- Availability:
- Ships Same Business Day
- Weight:
- 2.50 LBS
- RIDING STYLE:
- OFF-ROAD
- CYLINDER DIAMETER METRIC:
- 77.00 MM
- STYLE:
- STANDARD
- CYLINDER DIAMETER:
- 77,00 MM
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER
- BORE SIZE METRIC:
- 77.00 MM
- UNITS:
- EACH
$410.95 -
Cylinder Works Standard Bore Cylinder for Yamaha YFZ450 2004-2009 2012-2013 20001
CYLINDER WORKS
$410.95Your YFZ450's cylinder is the foundation of reliable power delivery—when it wears, you lose compression, efficiency, and overall engine performance. The Cylinder Works Standard Bore Cylinder (20001) is a direct bolt-on replacement that restores your...09310132- SKU:
- 09310132
- Availability:
- Ships Same Business Day
- Weight:
- 3.30 LBS
- CYLINDER DIAMETER:
- 95,00 MM
- OVERBORE METRIC:
- STANDARD
- STYLE:
- STANDARD
- COMPRESSION RATIO IMPERIAL:
- 12.0:1
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- DISPLACEMENT:
- 449 CC
- PRODUCT NAME:
- CYLINDER
- CYLINDER DIAMETER METRIC:
- 95.00 MM
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- ENGINE TYPE:
- 4-CYCLE
$410.95 -
Cylinder Works Big Bore Kit for Suzuki DR-Z400 2000-2004 41001-K01
CYLINDER WORKS
$837.95If you're running a stock DR-Z400, you're leaving power on the table. The Cylinder Works Big Bore Kit delivers a straightforward displacement increase with zero guesswork—everything you need arrives matched and ready to bolt on, so you can focus on...09310135- SKU:
- 09310135
- Availability:
- Ships Same Business Day
- Weight:
- 4.44 LBS
- COMPRESSION RATIO IMPERIAL:
- 11.3:1
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- STREET
- STYLE:
- BIG BORE
- CYLINDER DIAMETER:
- 94,00 MM
- DISPLACEMENT:
- 434 CC
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- OVERBORE METRIC:
- +4.00 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- CYLINDER DIAMETER METRIC:
- 94.00 MM
- RIDING STYLE:
- ATV
$837.95 -
Cylinder Works Standard Bore Cylinder Kit for Suzuki DR-Z400S 2000-2022 40001-K01
CYLINDER WORKS
$440.95The stock cylinder on your DR-Z400S will eventually wear, leading to lost compression, increased blow-by, and sluggish performance. The Cylinder Works Standard Bore Cylinder Kit restores your engine to factory specifications with a bolt-on replacement...09310139- SKU:
- 09310139
- Availability:
- Ships Same Business Day
- Weight:
- 3.61 LBS
- CYLINDER DIAMETER METRIC:
- 90.00 MM
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- CYLINDER DIAMETER:
- 90,00 MM
- PRODUCT NAME:
- CYLINDER
- RIDING STYLE:
- OFF-ROAD
- STYLE:
- STANDARD
- ENGINE TYPE:
- 4-CYCLE
- RIDING STYLE:
- STREET
$440.95 -
Cylinder Works Big Bore Cylinder Kit for Honda CRF150R 2012-2020 11004-K02
CYLINDER WORKS
$694.95If you're running a Honda CRF150R and want measurable gains in displacement and power output, a big bore kit is one of the most direct paths forward. The Cylinder Works 11004-K02 delivers bolt-on simplicity without sacrificing the precision fit and...09310485- SKU:
- 09310485
- Availability:
- Ships Same Business Day
- Weight:
- 2.80 LBS
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- CYLINDER DIAMETER:
- 68,00 MM
- DISPLACEMENT:
- 159 CC
- OVERBORE METRIC:
- +2.00 MM
- PRODUCT NAME:
- CYLINDER KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 11.7:1
- STYLE:
- BIG BORE
- CYLINDER DIAMETER METRIC:
- 68.00 MM
- ENGINE TYPE:
- 4-CYCLE
$694.95 -
Cylinder Works Big Bore Cylinder Kit for 2009-2015 Kawasaki KX450F 31011-K01
CYLINDER WORKS
$786.95If you're serious about extracting maximum displacement from your KX450F, the Cylinder Works Big Bore Kit delivers tangible power gains without the machine shop hassle. This bolt-on upgrade pairs a nickel silicon carbide-plated cylinder with Vertex...09310603- SKU:
- 09310603
- Availability:
- Ships Same Business Day
- Weight:
- 3.95 LBS
- DISPLACEMENT:
- 469 CC
- OVERBORE METRIC:
- +2.00 MM
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- PRODUCT NAME:
- CYLINDER KIT
- STYLE:
- BIG BORE
- UNITS:
- KIT
- COMPRESSION RATIO IMPERIAL:
- 12.5:1
- RIDING STYLE:
- OFF-ROAD
- CYLINDER DIAMETER:
- 98,00 MM
- CYLINDER DIAMETER METRIC:
- 98.00 MM
- ENGINE TYPE:
- 4-CYCLE
$786.95 -
Cylinder Works Standard Bore Cylinder Kit for Polaris RZR XP 900 2011-2013 60001-K02
CYLINDER WORKS
$1,204.95When your RZR XP 900's engine is ready for more, a complete cylinder kit eliminates the guesswork and delivers measurable gains in displacement and reliability. This Cylinder Works kit arrives as a true bolt-on solution—no machine work, no...09310657- SKU:
- 09310657
- Availability:
- Ships Same Business Day
- Weight:
- 10.00 LBS
- COMPRESSION RATIO IMPERIAL:
- 10.6:1
- CYLINDER DIAMETER:
- 93,00 MM
- ENGINE TYPE:
- 4-CYCLE
- PRODUCT NAME:
- CYLINDER KIT
- CYLINDER BORE COATING:
- NICKEL-SILICON CARBIDE
- DISPLACEMENT:
- 875 CC
- UNITS:
- KIT
- CYLINDER DIAMETER METRIC:
- 93.00 MM
- RIDING STYLE:
- UTV
- STYLE:
- STANDARD
$1,204.95 -
DEL WEST Intake Valves CRF250RIV10NDHF
DEL WEST
$155.95If you're building a CRF250R engine that demands maximum flow and rpm capability, DEL WEST intake valves are engineered for zero compromises. The 50-degree seat angle and flat valve face eliminate turbulence, delivering measurable gains in volumetric...09262469- SKU:
- 09262469
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- MATERIAL:
- TITANIUM
- APPLICATION:
- INTAKE
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
$155.95 -
On Sale
DEL WEST Exhaust Valves CRF250REV10NDHF
DEL WEST
MSRP: $155.95Now: $100.00Was: $155.95If you're building an engine that demands maximum airflow and can handle higher RPMs, the DEL WEST Exhaust Valves are engineered for serious competitors who refuse compromise. The 50-degree seat angle and flat valve face eliminate restrictions, while the...09262470- SKU:
- 09262470
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- MATERIAL:
- TITANIUM
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
MSRP: $155.95Now: $100.00Was: $155.95 -
On Sale
DEL WEST Exhaust Valve DWCRF450REV09ND
DEL WEST
MSRP: $155.95Now: $100.00Was: $155.95Off-road racing demands exhaust components that can withstand extreme conditions without sacrificing performance or reliability. The DEL WEST Exhaust Valve DWCRF450REV09ND is engineered specifically for high-stress competition environments, backed by a...09262471- SKU:
- 09262471
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- MATERIAL:
- TITANIUM
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- EACH
- APPLICATION:
- EXHAUST
MSRP: $155.95Now: $100.00Was: $155.95 -
DEL WEST Valve Spring Retainer DW-H-RX01-S
DEL WEST
$48.95When you're pushing your engine to the limit, valve spring retainers become a critical failure point. The DEL WEST DW-H-RX01-S is engineered from premium titanium to withstand extreme RPMs and valve loads without compromise. Trust the same retainers that...09262472- SKU:
- 09262472
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- RETAINER
- TYPE:
- VALVE SPRING
- UNITS:
- EACH
- APPLICATION:
- EXHAUST
$48.95 -
DEL WEST Valve Spring Retainer DW-H-RX02-S
DEL WEST
$48.95Del West valve spring retainers are engineered for maximum durability in high-RPM racing applications where standard components fail. Built by the same manufacturer trusted by NASCAR, Formula One, and professional motocross teams, these retainers deliver...09262473- SKU:
- 09262473
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- APPLICATION:
- INTAKE
- MATERIAL:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- VALVE SPRING
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- RETAINER
- UNITS:
- EACH
$48.95Qty in Cart: 0Quantity:Price:$48.95Subtotal: -
DEL WEST Exhaust Valve DW-CRF250R-EV08
DEL WEST
$155.95If you're running a CRF250R in competition or high-stress riding conditions, valve reliability directly impacts your engine's performance window and race-day consistency. DEL WEST exhaust valves are purpose-built for off-road demands, engineered to...09261042- SKU:
- 09261042
- Availability:
- Ships Same Business Day
- Weight:
- 0.15 LBS
- MATERIAL:
- TITANIUM
- UNITS:
- EACH
- APPLICATION:
- EXHAUST
- PRODUCT NAME:
- VALVE
- RIDING STYLE:
- OFF-ROAD
$155.95 -
DEL WEST Exhaust Valve DW-CRF250R-EV10
DEL WEST
$155.95If you're serious about off-road performance, your exhaust valve needs to match your ambition. DEL WEST has built its reputation on valves that survive the punishing conditions of competition—high RPMs, extreme temperatures, and relentless abuse. This...09261043- SKU:
- 09261043
- Availability:
- Ships Same Business Day
- Weight:
- 0.07 LBS
- APPLICATION:
- EXHAUST
- UNITS:
- EACH
- PRODUCT NAME:
- VALVE
- MATERIAL:
- TITANIUM
- RIDING STYLE:
- OFF-ROAD
$155.95
