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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HOT RODS Crankshaft Kit CBK0015
HOT RODS
$595.95If you're building a high-displacement engine or need a crankshaft assembly that meets OEM specs without compromise, the HOT RODS Crankshaft Kit CBK0015 delivers factory-assembled reliability with performance that matches or exceeds stock specifications...09210274- SKU:
- 09210274
- Availability:
- Ships Same Business Day
- Weight:
- 12.40 LBS
- PRODUCT NAME:
- CRANKSHAFT KIT
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- OEM
- UNITS:
- KIT
$595.95Qty in Cart: 0Quantity:Price:$595.95Subtotal: -
HOT RODS Crankshaft Kit CBK0014
HOT RODS
$502.95If you're building or rebuilding a high-performance engine, your crankshaft is the foundation of reliability and power delivery. The HOT RODS Crankshaft Kit CBK0014 arrives factory-assembled and true to OEM specifications, eliminating guesswork and...09210273- SKU:
- 09210273
- Availability:
- Ships Same Business Day
- Weight:
- 8.10 LBS
- PRODUCT NAME:
- CRANKSHAFT KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- TYPE:
- OEM
$502.95 -
HOT RODS Crankshaft Kit CBK0013
HOT RODS
$502.95If you're building a high-performance engine or refreshing a tired bottom end, the HOT RODS Crankshaft Kit CBK0013 delivers factory-spec reliability with the durability to handle increased output. This complete assembly arrives ready for installation,...09210272- SKU:
- 09210272
- Availability:
- Ships Same Business Day
- Weight:
- 8.50 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PRODUCT NAME:
- CRANKSHAFT KIT
- TYPE:
- OEM
$502.95 -
HOT RODS Crankshaft 4028
HOT RODS
$556.95Whether you're pushing your ATV to the limit on the track or maximizing reliability in demanding conditions, a robust crankshaft is the foundation of engine durability. The HOT RODS Crankshaft 4028 arrives factory-assembled and trued to OEM...09210237- SKU:
- 09210237
- Availability:
- Ships Same Business Day
- Weight:
- 10.01 LBS
- MATERIAL:
- 4140 STEEL
- UNITS:
- ASSEMBLY
- MODEL:
- 2-CYCLE
- RIDING STYLE:
- STREET
- COLOR/FINISH:
- STEEL
- FEATURES:
- STANDARD CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH METRIC:
- 72.00 MM
- TYPE:
- OEM STROKE
- DISPLACEMENT:
- 250 CC TO 300 CC
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
$556.95 -
HOT RODS Crankshaft 4066
HOT RODS
$318.95If you're building a high-displacement ATV engine or restoring a damaged crankshaft, the HOT RODS 4066 delivers factory-proven reliability without the machine work and custom fabrication typically required for long-stroke applications. This complete...09210075- SKU:
- 09210075
- Availability:
- Ships Same Business Day
- Weight:
- 4.61 LBS
- DISPLACEMENT:
- 85 CC TO 100 CC
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- MODEL:
- 2-CYCLE
- FEATURES:
- STANDARD CRANKSHAFT
- STROKE LENGTH METRIC:
- 45.80 MM
- TYPE:
- OEM STROKE
- COLOR/FINISH:
- STEEL
- MATERIAL:
- 4140 STEEL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- ASSEMBLY
$318.95 -
HOT RODS Crankshaft 4064
HOT RODS
$531.95If you're building a high-performance long-stroke engine for your ATV, the HOT RODS Crankshaft 4064 delivers the bottom-end reliability you need without compromise. This complete assembly arrives factory-trued to OEM specifications and pairs seamlessly...09210073- SKU:
- 09210073
- Availability:
- Ships Same Business Day
- Weight:
- 7.13 LBS
- MODEL:
- 4-CYCLE
- TYPE:
- OEM STROKE
- DISPLACEMENT:
- 250 CC
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- STROKE LENGTH METRIC:
- 53.60 MM
- FEATURES:
- HEAVY DUTY CRANKSHAFT
- MATERIAL:
- 4140 STEEL
- UNITS:
- ASSEMBLY
- COLOR/FINISH:
- STEEL
- RIDING STYLE:
- OFF-ROAD
$531.95 -
HOT RODS Crankshaft 4071
HOT RODS
$436.95If you're building a long-stroke engine for your ATV, the HOT RODS Crankshaft 4071 eliminates the guesswork and machine work typically required for displacement increases. This complete assembly arrives factory-assembled, trued to OEM specs, and ready to...09210051- SKU:
- 09210051
- Availability:
- Ships Same Business Day
- Weight:
- 4.81 LBS
- COLOR/FINISH:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- STROKE LENGTH METRIC:
- 48.90 MM
- DISPLACEMENT:
- 85 CC TO 105 CC
- MATERIAL:
- 4140 STEEL
- UNITS:
- ASSEMBLY
- FEATURES:
- STANDARD CRANKSHAFT
- MODEL:
- 2-CYCLE
- TYPE:
- OEM STROKE
$436.95 -
HOT RODS Crankshaft - Stroker 4148
HOT RODS
$645.95A stroker crankshaft is the foundation of serious displacement gains, and the HOT RODS 4148 delivers reliable long-stroke performance without the machine work typically required for these builds. By pairing this crankshaft with HOT RODS'...09210040- SKU:
- 09210040
- Availability:
- Ships Same Business Day
- Weight:
- 9.75 LBS
- DISPLACEMENT:
- 470 CC
- MODEL:
- 4-CYCLE
- TYPE:
- STROKER
- FEATURES:
- HEAVY DUTY CRANKSHAFT
- MATERIAL:
- 4140 STEEL
- STROKE LENGTH METRIC:
- 65.00 MM
- UNITS:
- ASSEMBLY
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- COLOR/FINISH:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- STROKE LENGTH:
- 65,00 MM
$645.95Qty in Cart: 0Quantity:Price:$645.95Subtotal: -
HOT RODS Crankshaft - Stroker 4149
HOT RODS
$592.95Maximize your ATV's displacement and low-end torque without extensive engine machine work. The HOT RODS Stroker 4149 crankshaft delivers proven long-stroke performance through precision engineering and factory-matched components designed specifically for...09210039- SKU:
- 09210039
- Availability:
- Ships Same Business Day
- Weight:
- 6.88 LBS
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- STROKE LENGTH:
- 56,60 MM
- TYPE:
- STROKER
- FEATURES:
- STANDARD CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
- DISPLACEMENT:
- 264 CC
- MODEL:
- 4-CYCLE
- COLOR/FINISH:
- STEEL
- MATERIAL:
- 4140 STEEL
- STROKE LENGTH METRIC:
- 56.60 MM
- UNITS:
- ASSEMBLY
$592.95 -
HOT RODS Crankshaft Assembly 4048
HOT RODS
$464.95If you're building a long-stroke engine for your ATV, you need a crankshaft assembly engineered to handle the demands of increased displacement and sustained performance. The HOT RODS Crankshaft Assembly 4048 arrives factory-assembled and trued to OEM...09210015- SKU:
- 09210015
- Availability:
- Ships Same Business Day
- Weight:
- 9.80 LBS
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- MODEL:
- 4-CYCLE
- COLOR/FINISH:
- STEEL
- DISPLACEMENT:
- 450 CC
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- OEM STROKE
- FEATURES:
- HEAVY DUTY CRANKSHAFT
- MATERIAL:
- 4140 STEEL
- STROKE LENGTH METRIC:
- 62.00 MM
- UNITS:
- ASSEMBLY
$464.95 -
HOT RODS Crankshaft Assembly 4049
HOT RODS
$489.95If you're rebuilding a high-performance four-stroke or planning a long-stroke conversion on your ATV, starting with a properly assembled crankshaft is non-negotiable. The HOT RODS Crankshaft Assembly 4049 arrives factory-assembled and trued to OEM...09210013- SKU:
- 09210013
- Availability:
- Ships Same Business Day
- Weight:
- 6.95 LBS
- PRODUCT NAME:
- CRANKSHAFT ASSEMBLY
- MODEL:
- 4-CYCLE
- UNITS:
- ASSEMBLY
- COLOR/FINISH:
- STEEL
- RIDING STYLE:
- OFF-ROAD
- TYPE:
- OEM STROKE
- DISPLACEMENT:
- 250 CC
- FEATURES:
- HEAVY DUTY CRANKSHAFT
- MATERIAL:
- 4140 STEEL
- STROKE LENGTH METRIC:
- 53.60 MM
$489.95 -
HOT RODS Wrist Pin Bearing WB104
HOT RODS
$18.95Wrist pin bearings are critical wear items in high-RPM applications, and OEM-quality replacement units are essential for maintaining engine reliability and performance. The HOT RODS WB104 delivers factory-spec durability with design enhancements...09130302- SKU:
- 09130302
- Availability:
- Ships Same Business Day
- Weight:
- 0.10 LBS
- DISPLACEMENT:
- 65 CC
- UNITS:
- EACH
- TYPE:
- WRIST PIN
- PRODUCT NAME:
- BEARING
- RIDING STYLE:
- OFF-ROAD
$18.95 -
On Sale
ATHENA Piston Ring Set S41316178
ATHENA
MSRP: $57.95Now: $52.00Was: $57.95Maintaining proper ring seal is critical to engine performance, compression retention, and oil control—especially in high-boost or high-RPM applications. The ATHENA Piston Ring Set S41316178 delivers OEM-quality ring geometry and material specifications...09120374- SKU:
- 09120374
- Availability:
- Ships Same Business Day
- Weight:
- 0.03 LBS
- BORE SIZE METRIC:
- 100.00 MM
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- PISTON RING
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- FORGED
- UNITS:
- SET
MSRP: $57.95Now: $52.00Was: $57.95 -
VERTEX Ring Set 53010005600
VERTEX
$29.95Piston ring degradation is one of the fastest ways to lose compression, power, and engine reliability—whether you're running a high-revving two-stroke or a four-stroke workhorse. VERTEX Ring Set 53010005600 delivers OEM-quality replacement rings with...09120366- SKU:
- 09120366
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- UNITS:
- SET
- RIDING STYLE:
- OFF-ROAD
- PRODUCT NAME:
- PISTON RING
- PISTON DIAMETER METRIC:
- 55.95 MM
$29.95Qty in Cart: 0Quantity:Price:$29.95Subtotal: -
On Sale
ATHENA Piston Ring Set S41316157
ATHENA
MSRP: $15.95Now: $14.00Was: $15.95Maintaining proper ring seal is critical to engine performance, compression, and longevity—especially in high-boost or high-RPM applications where factory rings fall short. The ATHENA Piston Ring Set S41316157 is engineered to work seamlessly with Athena...09120104- SKU:
- 09120104
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- PISTON MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- PISTON RING
- ENGINE TYPE:
- 2-STROKE
- BORE SIZE METRIC:
- 57.94 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- SET
MSRP: $15.95Now: $14.00Was: $15.95 -
On Sale
ATHENA Piston Ring Set S41316119
ATHENA
MSRP: $42.95Now: $39.00Was: $42.95When you've invested in forged pistons, your ring set is the critical seal between combustion and oil control—cheap rings will tank your compression, spike blowby, and leave you stranded. The ATHENA Piston Ring Set S41316119 is engineered to exact OEM...09120103- SKU:
- 09120103
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- BORE SIZE METRIC:
- 94 MM
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- PISTON RING
- RIDING STYLE:
- ATV
- PISTON MATERIAL:
- FORGED
- UNITS:
- SET
MSRP: $42.95Now: $39.00Was: $42.95 -
On Sale
ATHENA Piston Ring Set S41316062
ATHENA
MSRP: $42.95Now: $39.00Was: $42.95Piston rings are critical to engine sealing and compression—worn or damaged rings compromise power output, increase blow-by, and accelerate engine wear. The ATHENA Piston Ring Set S41316062 is engineered as a direct replacement for Athena Forged Pistons,...09120101- SKU:
- 09120101
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- PRODUCT NAME:
- PISTON RING
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 100.00 MM
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- FORGED
- RIDING STYLE:
- ATV
- UNITS:
- SET
MSRP: $42.95Now: $39.00Was: $42.95 -
On Sale
PROX Ring Set 02.1402
PROX
MSRP: $54.95Now: $47.00Was: $54.95Proper ring sealing is fundamental to engine efficiency and longevity—worn or substandard rings cause blow-by, oil consumption, and power loss. The PROX Ring Set 02.1402 delivers OEM-equivalent performance with Japanese manufacturing precision, restoring...09120047- SKU:
- 09120047
- Availability:
- Ships Same Business Day
- Weight:
- 0.05 LBS
- UNITS:
- SET
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON RING
- RIDING STYLE:
- OFF-ROAD
MSRP: $54.95Now: $47.00Was: $54.95Qty in Cart: 0Quantity:Price:MSRP: $54.95Now: $47.00Was: $54.95Subtotal: -
On Sale
ATHENA Piston Ring Set - Standard S41316016
ATHENA
MSRP: $34.95Now: $31.00Was: $34.95Piston rings are the critical seal between your piston and cylinder wall—they control compression, manage oil consumption, and directly impact power delivery and engine longevity. If you're running Athena Forged Pistons, using the matching OEM ring set...09120021- SKU:
- 09120021
- Availability:
- Ships Same Business Day
- Weight:
- 0.03 LBS
- BORE SIZE METRIC:
- 71.93 MM
- PISTON MATERIAL:
- FORGED
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- PISTON RING
- UNITS:
- SET
- RIDING STYLE:
- OFF-ROAD
MSRP: $34.95Now: $31.00Was: $34.95Qty in Cart: 0Quantity:Price:MSRP: $34.95Now: $31.00Was: $34.95Subtotal: -
JE PISTONS Piston Kit 379030
JE PISTONS
$314.99If you're building or rebuilding an engine for competition or high-output street duty, piston quality directly determines your engine's reliability ceiling. JE Pistons' 379030 kit delivers the precision engineering and material science required to...09106391- SKU:
- 09106391
- Availability:
- Ships Same Business Day
- Weight:
- 0.61 LBS
- BORE SIZE METRIC:
- 78.00 MM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE METRIC:
- STANDARD
- COMPRESSION RATIO IMPERIAL:
- 14.5:1
- BORE - OVERSIZE:
- STANDARD
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$314.99
