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ATV/UTV Engine

ATV/UTV Engine

ATV/UTV Engine

ATV/UTV Engine Parts at JJ Motorsports

Maximize your ATV or UTV's engine life with top-quality components from JJ Motorsports. Our selection includes gasket kits, connecting rods, water pump rebuild kits, and timing plugs designed for reliable sealing, strength, and easy installation in demanding off-road conditions. Compatible with Polaris, Can-Am, Honda, and more, these parts ensure peak power, reduced wear, and efficient operation for trail riding or utility work.

Shop trusted brands like Moose Racing for rebuild kits and Winderosa for gaskets. Explore related categories such as ATV/UTV air and fuel for intake upgrades or ATV/UTV drivetrain for transmission enhancements.

Top ATV/UTV Engine Products

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
  • On Sale
    ATHENA Top End Gasket Kit - Polaris P400427600015

    ATHENA Top End Gasket Kit - Polaris P400427600015

    ATHENA

    MSRP: $73.95
    Now: $67.00
    Was: $73.95
    Specifically designed for the pro, semi-pro and amateur rider who freshens up their engine prior to a race or during midseason. Gives the rider a choice of using standard gas with stock compression,...
    09344905
    SKU:
    09344905
    Availability:
    Ships Same Business Day
    Weight:
    0.10 LBS
    MATERIAL:
    SILICONE
    UNITS:
    KIT
    PRODUCT NAME:
    GASKET KIT
    RIDING STYLE:
    ATV
    TYPE:
    TOP END
    MSRP: $73.95
    Now: $67.00
    Was: $73.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $73.95
    Now: $67.00
    Was: $73.95
    Subtotal:
  • On Sale
    ATHENA Top End Gasket Kit - Polaris P400427620021

    ATHENA Top End Gasket Kit - Polaris P400427620021

    ATHENA

    MSRP: $139.95
    Now: $126.00
    Was: $139.95
    Specifically designed for the pro, semi-pro and amateur rider who freshens up their engine prior to a race or during midseason. Gives the rider a choice of using standard gas with stock compression,...
    09343194
    SKU:
    09343194
    Availability:
    Ships Same Business Day
    Weight:
    0.45 LBS
    ENGINE TYPE:
    4-STROKE
    PRODUCT NAME:
    GASKET KIT
    MATERIAL:
    STEEL
    RIDING STYLE:
    UTV
    TYPE:
    TOP END
    UNITS:
    KIT
    MSRP: $139.95
    Now: $126.00
    Was: $139.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $139.95
    Now: $126.00
    Was: $139.95
    Subtotal:
  • On Sale
    ATHENA Top End Gasket Kit - Polaris P400427620022

    ATHENA Top End Gasket Kit - Polaris P400427620022

    ATHENA

    MSRP: $139.95
    Now: $126.00
    Was: $139.95
    Specifically designed for the pro, semi-pro and amateur rider who freshens up their engine prior to a race or during midseason. Gives the rider a choice of using standard gas with stock compression,...
    09343196
    SKU:
    09343196
    Availability:
    Ships Same Business Day
    Weight:
    0.50 LBS
    ENGINE TYPE:
    4-STROKE
    PRODUCT NAME:
    GASKET KIT
    TYPE:
    TOP END
    MATERIAL:
    STEEL
    RIDING STYLE:
    UTV
    UNITS:
    KIT
    MSRP: $139.95
    Now: $126.00
    Was: $139.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $139.95
    Now: $126.00
    Was: $139.95
    Subtotal:
  • On Sale
    ATHENA Piston Kit S4C06800001A ATHENA Piston Kit S4C06800001A

    ATHENA Piston Kit S4C06800001A

    ATHENA

    MSRP: $134.95
    Now: $121.00
    Was: $134.95
    Includes rings, clips and pin, Easy-to-follow step-by-step installation instructions
    09101332
    SKU:
    09101332
    Availability:
    Ships Same Business Day
    Weight:
    0.65 LBS
    PISTON DIAMETER METRIC:
    67.95 MM
    PISTON SIZE METRIC:
    STANDARD SIZE A
    PRODUCT NAME:
    PISTON
    STYLE:
    CAST BIG BORE
    COMPRESSION RATIO IMPERIAL:
    11.9:1
    ENGINE TYPE:
    2-STROKE
    RIDING STYLE:
    ATV
    UNITS:
    EACH
    MSRP: $134.95
    Now: $121.00
    Was: $134.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $134.95
    Now: $121.00
    Was: $134.95
    Subtotal:
  • On Sale
    ATHENA Piston Kit S4C06800001B

    ATHENA Piston Kit S4C06800001B

    ATHENA

    MSRP: $134.95
    Now: $121.00
    Was: $134.95
    Includes rings, clips and pin, Easy-to-follow step-by-step installation instructions
    09101333
    SKU:
    09101333
    Availability:
    Ships Same Business Day
    Weight:
    0.65 LBS
    PISTON DIAMETER METRIC:
    67.96 MM
    PRODUCT NAME:
    PISTON
    STYLE:
    CAST BIG BORE
    ENGINE TYPE:
    2-STROKE
    PISTON SIZE METRIC:
    STANDARD SIZE B
    COMPRESSION RATIO IMPERIAL:
    11.9:1
    RIDING STYLE:
    ATV
    UNITS:
    EACH
    MSRP: $134.95
    Now: $121.00
    Was: $134.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $134.95
    Now: $121.00
    Was: $134.95
    Subtotal:
  • On Sale
    ATHENA Cylinder Kit - TRX450R - 490C P400210100017

    ATHENA Cylinder Kit - TRX450R - 490C P400210100017

    ATHENA

    MSRP: $1,227.95
    Now: $1,105.00
    Was: $1,227.95
    Kits include aluminum cylinder with nickel-carbide coating designed with larger water jackets, Forged piston with molybdenum coating, Special gasket kit, Easy-to-follow step-by-step installation...
    09310667
    SKU:
    09310667
    Availability:
    Ships Same Business Day
    Weight:
    4.45 LBS
    CYLINDER BORE COATING:
    NICKEL-CARBIDE
    DISPLACEMENT:
    480 CC
    UNITS:
    KIT
    ENGINE TYPE:
    4-STROKE
    MATERIAL:
    ALUMINUM
    RIDING STYLE:
    ATV
    PRODUCT NAME:
    CYLINDER KIT
    STYLE:
    BIG BORE
    BORE SIZE METRIC:
    100.00 MM
    MSRP: $1,227.95
    Now: $1,105.00
    Was: $1,227.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $1,227.95
    Now: $1,105.00
    Was: $1,227.95
    Subtotal:
  • On Sale
    ATHENA Top End Gasket Kit - Polaris P400427620010

    ATHENA Top End Gasket Kit - Polaris P400427620010

    ATHENA

    MSRP: $70.95
    Now: $64.00
    Was: $70.95
    Specifically designed for the pro, semi-pro and amateur rider who freshens up their engine prior to a race or during midseason. Gives the rider a choice of using standard gas with stock compression,...
    09342173
    SKU:
    09342173
    Availability:
    Ships Same Business Day
    Weight:
    0.10 LBS
    MATERIAL:
    SILICONE
    TYPE:
    TOP END
    UNITS:
    KIT
    PRODUCT NAME:
    GASKET KIT
    RIDING STYLE:
    ATV
    MSRP: $70.95
    Now: $64.00
    Was: $70.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $70.95
    Now: $64.00
    Was: $70.95
    Subtotal:
  • On Sale
    ATHENA Top End Gasket Kit - Polaris P400427620013

    ATHENA Top End Gasket Kit - Polaris P400427620013

    ATHENA

    MSRP: $131.95
    Now: $119.00
    Was: $131.95
    Specifically designed for the pro, semi-pro and amateur rider who freshens up their engine prior to a race or during midseason. Gives the rider a choice of using standard gas with stock compression,...
    09342175
    SKU:
    09342175
    Availability:
    Ships Same Business Day
    Weight:
    0.33 LBS
    UNITS:
    KIT
    ENGINE TYPE:
    4-STROKE
    PRODUCT NAME:
    GASKET KIT
    RIDING STYLE:
    ATV
    TYPE:
    TOP END
    MSRP: $131.95
    Now: $119.00
    Was: $131.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $131.95
    Now: $119.00
    Was: $131.95
    Subtotal:
  • On Sale
    ATHENA Gasket Kit - YFZ350 P400485160021

    ATHENA Gasket Kit - YFZ350 P400485160021

    ATHENA

    MSRP: $38.95
    Now: $38.00
    Was: $38.95
    Kits include aluminum cylinder with nickel-carbide coating designed with larger water jackets, Forged piston with molybdenum coating, Special gasket kit, Easy-to-follow step-by-step installation...
    09342194
    SKU:
    09342194
    Availability:
    Ships Same Business Day
    Weight:
    0.14 LBS
    BORE SIZE METRIC:
    68.00 MM
    RIDING STYLE:
    ATV
    TYPE:
    TOP END
    UNITS:
    KIT
    BORE SIZE:
    68,00 MM
    PRODUCT NAME:
    GASKET KIT
    MSRP: $38.95
    Now: $38.00
    Was: $38.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $38.95
    Now: $38.00
    Was: $38.95
    Subtotal:
  • On Sale
    ATHENA Top End Gasket Kit - Polaris P400427600001

    ATHENA Top End Gasket Kit - Polaris P400427600001

    ATHENA

    MSRP: $33.95
    Now: $29.00
    Was: $33.95
    Specifically designed for the pro, semi-pro and amateur rider who freshens up their engine prior to a race or during midseason. Gives the rider a choice of using standard gas with stock compression,...
    400427600001
    SKU:
    400427600001
    Availability:
    Ships Same Business Day
    Weight:
    0.13 LBS
    MSRP: $33.95
    Now: $29.00
    Was: $33.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $33.95
    Now: $29.00
    Was: $33.95
    Subtotal:
  • On Sale
    ATHENA Top End Gasket Kit - Polaris P400427600002

    ATHENA Top End Gasket Kit - Polaris P400427600002

    ATHENA

    MSRP: $51.95
    Now: $44.00
    Was: $51.95
    Specifically designed for the pro, semi-pro and amateur rider who freshens up their engine prior to a race or during midseason. Gives the rider a choice of using standard gas with stock compression,...
    400427600002
    SKU:
    400427600002
    Availability:
    Ships Same Business Day
    Weight:
    0.13 LBS
    MSRP: $51.95
    Now: $44.00
    Was: $51.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $51.95
    Now: $44.00
    Was: $51.95
    Subtotal:
  • On Sale
    ATHENA Top End Gasket Kit - Polaris P400427600004

    ATHENA Top End Gasket Kit - Polaris P400427600004

    ATHENA

    MSRP: $47.95
    Now: $43.00
    Was: $47.95
    Specifically designed for the pro, semi-pro and amateur rider who freshens up their engine prior to a race or during midseason. Gives the rider a choice of using standard gas with stock compression,...
    400427600004
    SKU:
    400427600004
    Availability:
    Ships Same Business Day
    Weight:
    0.19 LBS
    MSRP: $47.95
    Now: $43.00
    Was: $47.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $47.95
    Now: $43.00
    Was: $47.95
    Subtotal:
  • On Sale
    ATHENA Top End Gasket Kit - Polaris P400427600006

    ATHENA Top End Gasket Kit - Polaris P400427600006

    ATHENA

    MSRP: $97.95
    Now: $84.00
    Was: $97.95
    Specifically designed for the pro, semi-pro and amateur rider who freshens up their engine prior to a race or during midseason. Gives the rider a choice of using standard gas with stock compression,...
    400427600006
    SKU:
    400427600006
    Availability:
    Ships Same Business Day
    Weight:
    0.50 LBS
    MSRP: $97.95
    Now: $84.00
    Was: $97.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $97.95
    Now: $84.00
    Was: $97.95
    Subtotal:
  • On Sale
    ATHENA Complete Gasket Kit - Polaris P400427850004

    ATHENA Complete Gasket Kit - Polaris P400427850004

    ATHENA

    MSRP: $54.95
    Now: $49.00
    Was: $54.95
    Superior-quality gasket sets from Athena, Head gaskets feature rubber-coated spring steel construction, Soft steel base gaskets are rubber coated, Steel core materials feature high springback and...
    400427850004
    SKU:
    400427850004
    Availability:
    Ships Same Business Day
    Weight:
    0.25 LBS
    MSRP: $54.95
    Now: $49.00
    Was: $54.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $54.95
    Now: $49.00
    Was: $54.95
    Subtotal:
  • Cylinder Works Big Bore Gasket Kit for Honda TRX450R 2004-2005 11003-G01

    Cylinder Works Big Bore Gasket Kit for Honda TRX450R 2004-2005 11003-G01

    CYLINDER WORKS

    $99.95
    If you're running a Honda TRX450R and want measurable gains in displacement and power without extensive machine work, this big bore kit delivers the displacement increase you need with minimal...
    09341526
    SKU:
    09341526
    Availability:
    Ships Same Business Day
    Weight:
    0.26 LBS
    BORE SIZE METRIC:
    OVERSIZED (+3.00 MM)
    TYPE:
    TOP END
    STYLE:
    BIG BORE
    PRODUCT NAME:
    GASKET KIT
    RIDING STYLE:
    ATV
    UNITS:
    KIT
    MATERIAL:
    NICKEL SILICON CARBIDE
    Qty in Cart: 0
    Quantity:
    Price:
    $99.95
    Subtotal:
  • Cylinder Works Big Bore Gasket Kit 94mm Bore Arctic Cat 400 DVX 2004-2008 41001-G01

    Cylinder Works Big Bore Gasket Kit 94mm Bore Arctic Cat 400 DVX 2004-2008 41001-G01

    CYLINDER WORKS

    $115.95
    When you're pushing your Arctic Cat 400 DVX to its limits, factory bore limitations hold you back. The Cylinder Works Big Bore Gasket Kit delivers a complete, ready-to-install solution that increases...
    09341527
    SKU:
    09341527
    Availability:
    Ships Same Business Day
    Weight:
    0.23 LBS
    RIDING STYLE:
    ADVENTURE TOURING / DUAL-SPORT
    TYPE:
    TOP END
    UNITS:
    KIT
    BORE SIZE METRIC:
    OVERSIZE (+4.00 MM)
    PRODUCT NAME:
    GASKET KIT
    STYLE:
    BIG BORE
    MATERIAL:
    NICKEL SILICON CARBIDE
    RIDING STYLE:
    OFF-ROAD
    ENGINE TYPE:
    4-STROKE
    RIDING STYLE:
    ATV
    $115.95
    Qty in Cart: 0
    Quantity:
    Price:
    $115.95
    Subtotal:
  • On Sale
    ATHENA Top End Gasket Kit - Honda P400210600305

    ATHENA Top End Gasket Kit - Honda P400210600305

    ATHENA

    MSRP: $107.95
    Now: $92.00
    Was: $107.95
    Keep your engine running at peak performance between races with the ATHENA Top End Gasket Kit. Whether you're running on pump gas with stock compression or pushing higher octane fuel with elevated...
    09344871
    SKU:
    09344871
    Availability:
    Ships Same Business Day
    Weight:
    0.30 LBS
    MATERIAL:
    SILICONE
    UNITS:
    KIT
    PRODUCT NAME:
    GASKET KIT
    RIDING STYLE:
    ATV
    TYPE:
    TOP END
    MSRP: $107.95
    Now: $92.00
    Was: $107.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $107.95
    Now: $92.00
    Was: $107.95
    Subtotal:
  • HOT RODS Crank Seal - YFZ350 K018

    HOT RODS Crank Seal - YFZ350 K018

    HOT RODS

    $26.95
    A leaking countershaft seal doesn't just waste oil—it compromises engine reliability and forces you off the track or out of the garage. The HOT RODS Crank Seal kit delivers a complete, bolt-on...
    09350069
    SKU:
    09350069
    Availability:
    Ships Same Business Day
    Weight:
    0.19 LBS
    UNITS:
    KIT
    APPLICATION:
    MAIN CRANKSHAFT
    PRODUCT NAME:
    SEAL KIT
    TYPE:
    OIL
    RIDING STYLE:
    ATV
    $26.95
    Qty in Cart: 0
    Quantity:
    Price:
    $26.95
    Subtotal:
  • HOT RODS Counter Balancer Bearing Kit BBK0021

    HOT RODS Counter Balancer Bearing Kit BBK0021

    HOT RODS

    $52.95
    A counter balancer bearing kit is essential when performing any new counter balancer installation, engine case rebuild, or shaft replacement on modern 4-stroke engines. Using OEM-quality bearings...
    09500612
    SKU:
    09500612
    Availability:
    Ships Same Business Day
    Weight:
    0.20 LBS
    RIDING STYLE:
    ATV
    TYPE:
    COUNTERBALANCE SHAFT
    UNITS:
    KIT
    PRODUCT NAME:
    BEARING KIT
    $52.95
    Qty in Cart: 0
    Quantity:
    Price:
    $52.95
    Subtotal:
  • HOT RODS Counter Balancer Bearing Kit - Honda BBK0005

    HOT RODS Counter Balancer Bearing Kit - Honda BBK0005

    HOT RODS

    $21.95
    If you're rebuilding or installing a new counter balancer in your 4-stroke engine, bearing failure is a silent killer that leads to catastrophic damage. The HOT RODS Counter Balancer Bearing Kit...
    09500541
    SKU:
    09500541
    Availability:
    Ships Same Business Day
    Weight:
    0.30 LBS
    UNITS:
    KIT
    RIDING STYLE:
    ATV
    TYPE:
    COUNTERBALANCE SHAFT
    PRODUCT NAME:
    BEARING KIT
    Qty in Cart: 0
    Quantity:
    Price:
    $21.95
    Subtotal:
  • Total: items /

Adding your products to cart

Big Power, Nice Sound!

Picked up a Pro Circuit pipe and silencer for my YZ125 it’s a game changer. The power feels way better and the sound is awesome.

Tyler D. - 06/12

Perfect Fit

First time ordering here and dang y’all knocked it outta the park! The wheels fit my Ranger UTV perfect, and I’ll definitely be back for more 5 stars all day!

Sarah L. - 08/24

Fast Shipping!!

Ordered on a Monday, and it was on my doorstep by Wednesday! Super impressed with how fast the shipping was.

Jason P. - 09/13

Helps keep cool, works great!

Bought the dual pass Allstar radiator for my build, and it’s been solid. Keeps the engine running cool even on the hottest days no complaints here!

Jake M. - 05/21

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