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
ATHENA Connecting Rod Kit P40321015
ATHENA
MSRP: $112.95Now: $102.00Was: $112.95High-quality, lightweight connecting rods, Made with similar materials to the OEM component to ensure the same performance, Superficial high-frequency treatment for higher resistance that reduces rotational and alternating stresses, Kits include...09230500- SKU:
- 09230500
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- DISPLACEMENT:
- 125 CC
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- RIDING STYLE:
- STREET
MSRP: $112.95Now: $102.00Was: $112.95 -
On Sale
ATHENA Connecting Rod Kit P40321016
ATHENA
MSRP: $112.95Now: $102.00Was: $112.95High-quality, lightweight connecting rods, Made with similar materials to the OEM component to ensure the same performance, Superficial high-frequency treatment for higher resistance that reduces rotational and alternating stresses, Kits include...09230501- SKU:
- 09230501
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- DISPLACEMENT:
- 125 CC
MSRP: $112.95Now: $102.00Was: $112.95 -
On Sale
ATHENA Connecting Rod Kit P40321017
ATHENA
MSRP: $112.95Now: $102.00Was: $112.95High-quality, lightweight connecting rods, Made with similar materials to the OEM component to ensure the same performance, Superficial high-frequency treatment for higher resistance that reduces rotational and alternating stresses, Kits include...09230502- SKU:
- 09230502
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- DISPLACEMENT:
- 125 CC
- PRODUCT NAME:
- CONNECTING ROD KIT
MSRP: $112.95Now: $102.00Was: $112.95 -
On Sale
ATHENA Connecting Rod Kit P40321021
ATHENA
MSRP: $156.95Now: $141.00Was: $156.95High-quality, lightweight connecting rods, Made with similar materials to the OEM component to ensure the same performance, Superficial high-frequency treatment for higher resistance that reduces rotational and alternating stresses, Kits include...09230505- SKU:
- 09230505
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
- DISPLACEMENT:
- 250 CC
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $156.95Now: $141.00Was: $156.95 -
On Sale
ATHENA Connecting Rod Kit P40321024
ATHENA
MSRP: $160.95Now: $145.00Was: $160.95High-quality, lightweight connecting rods, Made with similar materials to the OEM component to ensure the same performance, Superficial high-frequency treatment for higher resistance that reduces rotational and alternating stresses, Kits include...09230508- SKU:
- 09230508
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- DISPLACEMENT:
- 450 CC
- PRODUCT NAME:
- CONNECTING ROD KIT
MSRP: $160.95Now: $145.00Was: $160.95 -
On Sale
ATHENA Connecting Rod Kit P40321050
ATHENA
MSRP: $257.02Now: $231.00Was: $257.02High-quality, lightweight connecting rods, Made with similar materials to the OEM component to ensure the same performance, Superficial high-frequency treatment for higher resistance that reduces rotational and alternating stresses, Kits include...09230576- SKU:
- 09230576
- Availability:
- Ships Same Business Day
- Weight:
- 1.16 LBS
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- DISPLACEMENT:
- 250 CC
- RIDING STYLE:
- STREET
- UNITS:
- KIT
MSRP: $257.02Now: $231.00Was: $257.02 -
On Sale
ATHENA Connecting Rod Kit P40321053
ATHENA
MSRP: $121.95Now: $110.00Was: $121.95High-quality, lightweight connecting rods, Made with similar materials to the OEM component to ensure the same performance, Superficial high-frequency treatment for higher resistance that reduces rotational and alternating stresses, Kits include...09230578- SKU:
- 09230578
- Availability:
- Ships Same Business Day
- Weight:
- 0.51 LBS
- DISPLACEMENT:
- 65 CC
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $121.95Now: $110.00Was: $121.95 -
On Sale
ATHENA Connecting Rod Kit P40321054
ATHENA
MSRP: $124.95Now: $112.00Was: $124.95High-quality, lightweight connecting rods, Made with similar materials to the OEM component to ensure the same performance, Superficial high-frequency treatment for higher resistance that reduces rotational and alternating stresses, Kits include...09230579- SKU:
- 09230579
- Availability:
- Ships Same Business Day
- Weight:
- 0.56 LBS
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- DISPLACEMENT:
- 85 CC
MSRP: $124.95Now: $112.00Was: $124.95 -
On Sale
ATHENA Piston Ring Set S41316030
ATHENA
MSRP: $42.95Now: $39.00Was: $42.95Replacement rings for Athena Forged Pistons09120158- SKU:
- 09120158
- Availability:
- Ships Same Business Day
- Weight:
- 0.06 LBS
- BORE SIZE METRIC:
- 95.50 MM
- 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 S41316133
ATHENA
MSRP: $33.95Now: $31.00Was: $33.95Replacement rings for Athena Forged Pistons09120159- SKU:
- 09120159
- Availability:
- Ships Same Business Day
- Weight:
- 0.03 LBS
- RIDING STYLE:
- OFF-ROAD
- BORE SIZE METRIC:
- 83.00 MM
- PRODUCT NAME:
- PISTON RING
- UNITS:
- SET
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- FORGED
MSRP: $33.95Now: $31.00Was: $33.95 -
On Sale
ATHENA Piston Ring Set S41316130
ATHENA
MSRP: $15.95Now: $14.00Was: $15.95Replacement rings for Athena Forged Pistons09120160- SKU:
- 09120160
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- UNITS:
- SET
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM
- BORE SIZE METRIC:
- 53.94 MM
- PRODUCT NAME:
- PISTON RING
- RIDING STYLE:
- OFF-ROAD
MSRP: $15.95Now: $14.00Was: $15.95 -
On Sale
ATHENA Piston Ring Set S41316089
ATHENA
MSRP: $39.95Now: $36.00Was: $39.95Replacement rings for Athena Forged Pistons09120281- SKU:
- 09120281
- Availability:
- Ships Same Business Day
- Weight:
- 0.02 LBS
- PRODUCT NAME:
- PISTON RING
- UNITS:
- SET
- BORE SIZE METRIC:
- 82.00 MM
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- FORGED
MSRP: $39.95Now: $36.00Was: $39.95 -
On Sale
ATHENA Crankcase - Yamaha S410130320004
ATHENA
MSRP: $221.95Now: $200.00Was: $221.95Made of special steel and manufactured with CNC high-precision machinery, Standard stroke09210019- SKU:
- 09210019
- Availability:
- Ships Same Business Day
- Weight:
- 2.90 LBS
- RIDING STYLE:
- STREET
- PRODUCT NAME:
- CRANKSHAFT
- UNITS:
- EACH
MSRP: $221.95Now: $200.00Was: $221.95 -
On Sale
ATHENA Crankcase - Yamaha YZ85 S410485320002
ATHENA
MSRP: $171.95Now: $155.00Was: $171.95Made of special steel and manufactured with CNC high-precision machinery, Standard stroke09210589- SKU:
- 09210589
- Availability:
- Ships Same Business Day
- Weight:
- 4.16 LBS
- UNITS:
- EACH
- PRODUCT NAME:
- CRANKSHAFT
- RIDING STYLE:
- OFF-ROAD
MSRP: $171.95Now: $155.00Was: $171.95 -
On Sale
ATHENA Piston Kit S4F05400003B
ATHENA
MSRP: $167.95Now: $151.00Was: $167.95Two-stroke pistons are made from 4032 silicium, Four-stroke pistons are made from 2618 silicium - the same material used to produce Formula 1 pistons, Both include 3% copper in materials for better heat resistance, All pistons are forged using a...09100067- SKU:
- 09100067
- Availability:
- Ships Same Business Day
- Weight:
- 0.36 LBS
- DISPLACEMENT:
- 125 CC
- BORE SIZE METRIC:
- 53.96 MM
- COMPRESSION RATIO IMPERIAL:
- STOCK
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- DISPLACEMENT:
- 124 CC
- PISTON HEAD SHAPE:
- FLAT TOP
- TYPE:
- B
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- 4032 ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
MSRP: $167.95Now: $151.00Was: $167.95 -
ACERBIS X-Power Cover Kit - White - KTM/Husqvarna 2726840002
ACERBIS
$67.95Engine crankcase and Ignition/clutch cover, Protects against dirt, debris and impact, Installs easily with stock crankcase and Ignition/clutch cover bolts, Molded openings for easy access to oil cap and filter cover, Heat resistant; won't interfere with...09401768- SKU:
- 09401768
- Availability:
- Ships Same Business Day
- Weight:
- 1.46 LBS
- MATERIAL:
- PLASTIC
- PRODUCT NAME:
- COVER
- TYPE:
- ENGINE
- COLOR/FINISH:
- WHITE
- MODEL:
- X-POWER
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$67.95 -
ACERBIS X-Power Cover Kit - Black - KTM/Husqvarna 2732130001
ACERBIS
$69.95Engine crankcase and Ignition/clutch cover, Protects against dirt, debris and impact, Installs easily with stock crankcase and Ignition/clutch cover bolts, Molded openings for easy access to oil cap and filter cover, Heat resistant; won't interfere with...09401769- SKU:
- 09401769
- Availability:
- Ships Same Business Day
- Weight:
- 1.46 LBS
- TYPE:
- ENGINE
- COLOR/FINISH:
- BLACK
- MATERIAL:
- PLASTIC
- PRODUCT NAME:
- COVER
- RIDING STYLE:
- OFF-ROAD
- MODEL:
- X-POWER
- UNITS:
- KIT
$69.95 -
ACERBIS X-Power Cover Kit - Black - Honda 2856840001
ACERBIS
$76.95Engine crankcase and Ignition/clutch cover, Protects against dirt, debris and impact, Installs easily with stock crankcase and Ignition/clutch cover bolts, Molded openings for easy access to oil cap and filter cover, Heat resistant; won't interfere with...09401994- SKU:
- 09401994
- Availability:
- Ships Same Business Day
- Weight:
- 1.35 LBS
- MATERIAL:
- PLASTIC
- TYPE:
- ENGINE
- MODEL:
- X-POWER
- PRODUCT NAME:
- COVER
- UNITS:
- KIT
- COLOR/FINISH:
- BLACK
- RIDING STYLE:
- OFF-ROAD
$76.95 -
ACERBIS X-Power Cover Kit - Black - Gas Gas 2872870001
ACERBIS
$76.95Engine crankcase and Ignition/clutch cover, Protects against dirt, debris and impact, Installs easily with stock crankcase and Ignition/clutch cover bolts, Molded openings for easy access to oil cap and filter cover, Heat resistant; won't interfere with...09401996- SKU:
- 09401996
- Availability:
- Ships Same Business Day
- Weight:
- 1.41 LBS
- COLOR/FINISH:
- BLACK
- UNITS:
- KIT
- MODEL:
- X-POWER
- PRODUCT NAME:
- COVER
- RIDING STYLE:
- STREET
- TYPE:
- ENGINE
- MATERIAL:
- PLASTIC
$76.95 -
K & N Oil Filter KN-650
K & N
$11.99K&N delivers a premium oil filter which is built with a synthetic media specifically designed to withstand the high concentrates of synthetic racing oils, A large filter media provides high-flow rates and outstanding oil filtration to keep your motor...07120554- SKU:
- 07120554
- Availability:
- Ships Same Business Day
- Weight:
- 0.11 LBS
- BASE COLOR:
- YELLOW
- BASE FINISH:
- NATURAL
- STYLE:
- STANDARD
- UNITS:
- EACH
- LENGTH METRIC:
- 128 MM
- PRODUCT NAME:
- OIL FILTER
- RIDING STYLE:
- STREET
- COLOR/FINISH:
- YELLOW
- FILTER MEDIA MATERIAL:
- SYNTHETIC
- RIDING STYLE:
- ADVENTURE TOURING / DUAL-SPORT
- TYPE:
- CARTRIDGE
$11.99
