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PROX

PROX

PROX

Prox Pistons, Gaskets, and Engine Components at JJ Motorsports

Prox, established in the late 1970s, is a respected brand in the powersports industry, specializing in high-performance aftermarket parts for motorcycles, ATVs, and off-road vehicles. With a focus on quality and innovation, Prox offers OEM-style replacements that deliver exceptional reliability and performance for both recreational riders and professionals.

At JJ Motorsports, we provide a comprehensive selection of Prox products, including complete gasket kits, top-end gasket sets, piston kits, connecting rod kits, crankshaft bearing/seal kits, and more. Whether you're rebuilding an engine or upgrading for better durability, Prox delivers precise-fit solutions compatible with major brands like Honda, Kawasaki, Suzuki, and KTM. Explore our inventory to find the ideal parts for your vehicle.

Key features of Prox products include precision engineering to OEM specifications, use of high-silicon-content aluminum alloys for pistons, double-forged construction for strength, and complete kits for easy installation. Shop now and enhance your powersports performance with Prox!

  • Product
  • Qty in Cart
  • Quantity
  • Price
  • Subtotal
  • On Sale
    PROX Piston Kit 01.4221.B

    PROX Piston Kit 01.4221.B

    PROX

    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    Your engine's piston kit is the foundation of reliable power delivery and longevity under load. Factory pistons wear, lose compression, and compromise performance—the PROX Piston Kit 01.4221.B...
    PX4221B
    SKU:
    PX4221B
    Availability:
    Ships Same Business Day
    Weight:
    0.42 LBS
    PISTON DIAMETER METRIC:
    53.97 MM
    RIDING STYLE:
    OFF-ROAD
    BORE SIZE METRIC:
    53.97 MM
    PISTON SIZE METRIC:
    STANDARD SIZE B
    PRODUCT NAME:
    PISTON KIT
    UNITS:
    EACH
    PISTON MATERIAL:
    ALUMINUM ALLOY
    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    Subtotal:
  • On Sale
    PROX Ring Set 02.4106

    PROX Ring Set 02.4106

    PROX

    MSRP: $24.95
    Now: $21.00
    Was: $24.95
    Piston rings are the critical seal between your combustion chamber and crankcase—when they wear, you lose compression, burn oil, and sacrifice power. The PROX Ring Set 02.4106 delivers OEM-quality...
    PX4230R
    SKU:
    PX4230R
    Availability:
    Ships Same Business Day
    Weight:
    0.05 LBS
    PISTON MATERIAL:
    ALUMINUM ALLOY
    RIDING STYLE:
    OFF-ROAD
    PRODUCT NAME:
    PISTON RING
    UNITS:
    SET
    MSRP: $24.95
    Now: $21.00
    Was: $24.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $24.95
    Now: $21.00
    Was: $24.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.1208.A3

    PROX Piston Kit 01.1208.A3

    PROX

    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    A worn or damaged piston kit compromises combustion efficiency, increases blow-by, and accelerates engine wear—ultimately costing you performance and reliability. The PROX Piston Kit 01.1208.A3...
    PX4240D
    SKU:
    PX4240D
    Availability:
    Ships Same Business Day
    Weight:
    0.38 LBS
    BORE SIZE METRIC:
    53.97 MM
    PISTON DIAMETER METRIC:
    53.96 MM
    PISTON MATERIAL:
    ALUMINUM ALLOY
    UNITS:
    EACH
    RIDING STYLE:
    OFF-ROAD
    PISTON SIZE METRIC:
    STANDARD SIZE A
    PRODUCT NAME:
    PISTON KIT
    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.1218.A1

    PROX Piston Kit 01.1218.A1

    PROX

    MSRP: $132.95
    Now: $90.00
    Was: $132.95
    A piston kit is the heart of engine reliability and performance—without proper pistons, you're risking catastrophic failure under boost or high RPM. The PROX Piston Kit 01.1218.A1 delivers OEM-grade...
    PX4260A
    SKU:
    PX4260A
    Availability:
    Ships Same Business Day
    Weight:
    0.38 LBS
    RIDING STYLE:
    OFF-ROAD
    PISTON DIAMETER METRIC:
    53.94 MM
    PRODUCT NAME:
    PISTON KIT
    BORE SIZE METRIC:
    53.94 MM
    PISTON SIZE METRIC:
    STANDARD SIZE A
    PISTON MATERIAL:
    ALUMINUM ALLOY
    UNITS:
    EACH
    MSRP: $132.95
    Now: $90.00
    Was: $132.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $132.95
    Now: $90.00
    Was: $132.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.1218.A2

    PROX Piston Kit 01.1218.A2

    PROX

    MSRP: $132.95
    Now: $90.00
    Was: $132.95
    A worn or damaged piston directly compromises engine efficiency, compression, and longevity—especially under sustained high-RPM operation. The PROX Piston Kit 01.1218.A2 delivers OEM-equivalent...
    PX4260B
    SKU:
    PX4260B
    Availability:
    Ships Same Business Day
    Weight:
    0.38 LBS
    BORE SIZE METRIC:
    53.95 MM
    PISTON DIAMETER METRIC:
    53.95 MM
    PRODUCT NAME:
    PISTON KIT
    PISTON MATERIAL:
    ALUMINUM ALLOY
    UNITS:
    EACH
    PISTON SIZE METRIC:
    STANDARD SIZE A
    RIDING STYLE:
    OFF-ROAD
    MSRP: $132.95
    Now: $90.00
    Was: $132.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $132.95
    Now: $90.00
    Was: $132.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.1218.A4

    PROX Piston Kit 01.1218.A4

    PROX

    MSRP: $132.95
    Now: $90.00
    Was: $132.95
    A piston kit is the backbone of engine reliability and performance—worn or damaged pistons lead to compression loss, increased blowby, and catastrophic engine failure. The PROX Piston Kit 01.1218.A4...
    PX4260D
    SKU:
    PX4260D
    Availability:
    Ships Same Business Day
    Weight:
    0.40 LBS
    PISTON DIAMETER METRIC:
    53.97 MM
    RIDING STYLE:
    OFF-ROAD
    BORE SIZE METRIC:
    53.97 MM
    PISTON MATERIAL:
    ALUMINUM ALLOY
    PRODUCT NAME:
    PISTON KIT
    UNITS:
    EACH
    PISTON SIZE METRIC:
    STANDARD SIZE A
    MSRP: $132.95
    Now: $90.00
    Was: $132.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $132.95
    Now: $90.00
    Was: $132.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.4108.A

    PROX Piston Kit 01.4108.A

    PROX

    MSRP: $93.95
    Now: $76.00
    Was: $93.95
    When your engine's internal components start to wear, piston degradation directly impacts compression, fuel efficiency, and overall power delivery. The PROX Piston Kit 01.4108.A is engineered as a...
    PX4280A
    SKU:
    PX4280A
    Availability:
    Ships Same Business Day
    Weight:
    0.30 LBS
    PISTON SIZE METRIC:
    STANDARD SIZE A
    PRODUCT NAME:
    PISTON KIT
    PISTON MATERIAL:
    ALUMINUM ALLOY
    UNITS:
    EACH
    PISTON DIAMETER METRIC:
    47.94 MM
    BORE SIZE METRIC:
    47.94 MM
    RIDING STYLE:
    OFF-ROAD
    MSRP: $93.95
    Now: $76.00
    Was: $93.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $93.95
    Now: $76.00
    Was: $93.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.4108.C

    PROX Piston Kit 01.4108.C

    PROX

    MSRP: $89.95
    Now: $76.00
    Was: $89.95
    When your engine demands precision and reliability, stock pistons won't cut it. The PROX Piston Kit 01.4108.C delivers OEM-equivalent performance with the tight tolerances and material integrity your...
    PX4280C
    SKU:
    PX4280C
    Availability:
    Ships Same Business Day
    Weight:
    0.30 LBS
    PISTON DIAMETER METRIC:
    47.96 MM
    PISTON MATERIAL:
    ALUMINUM ALLOY
    PISTON SIZE METRIC:
    STANDARD SIZE C
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    EACH
    BORE SIZE METRIC:
    47.96 MM
    PRODUCT NAME:
    PISTON KIT
    MSRP: $89.95
    Now: $76.00
    Was: $89.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $89.95
    Now: $76.00
    Was: $89.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.4121.A

    PROX Piston Kit 01.4121.A

    PROX

    MSRP: $99.95
    Now: $76.00
    Was: $99.95
    Factory pistons wear out or fail, leaving you with expensive downtime and compromised engine performance. The PROX Piston Kit 01.4121.A delivers OEM-equivalent quality at a fraction of the cost,...
    PX4281A
    SKU:
    PX4281A
    Availability:
    Ships Same Business Day
    Weight:
    0.42 LBS
    PISTON SIZE METRIC:
    STANDARD SIZE A
    PRODUCT NAME:
    PISTON KIT
    PISTON DIAMETER METRIC:
    48.45 MM
    PISTON MATERIAL:
    ALUMINUM ALLOY
    UNITS:
    EACH
    BORE SIZE METRIC:
    48.45 MM
    RIDING STYLE:
    OFF-ROAD
    MSRP: $99.95
    Now: $76.00
    Was: $99.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $99.95
    Now: $76.00
    Was: $99.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.4121.B

    PROX Piston Kit 01.4121.B

    PROX

    MSRP: $99.95
    Now: $76.00
    Was: $99.95
    When your engine demands reliability at high RPM, OEM-equivalent pistons aren't optional—they're essential. The PROX Piston Kit 01.4121.B delivers factory-spec performance with the precision...
    PX4281B
    SKU:
    PX4281B
    Availability:
    Ships Same Business Day
    Weight:
    0.42 LBS
    PISTON DIAMETER METRIC:
    48.46 MM
    PISTON MATERIAL:
    ALUMINUM ALLOY
    UNITS:
    EACH
    BORE SIZE METRIC:
    48.46 MM
    PISTON SIZE METRIC:
    STANDARD SIZE B
    PRODUCT NAME:
    PISTON KIT
    RIDING STYLE:
    OFF-ROAD
    MSRP: $99.95
    Now: $76.00
    Was: $99.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $99.95
    Now: $76.00
    Was: $99.95
    Subtotal:
  • On Sale
    PROX Ring Set 02.4121

    PROX Ring Set 02.4121

    PROX

    MSRP: $24.95
    Now: $21.00
    Was: $24.95
    Piston ring wear directly impacts compression, blow-by, and fuel efficiency—making quality ring sets essential for maintaining peak engine performance. The PROX Ring Set 02.4121 delivers...
    PX4281R
    SKU:
    PX4281R
    Availability:
    Ships Same Business Day
    Weight:
    0.02 LBS
    PISTON MATERIAL:
    ALUMINUM ALLOY
    RIDING STYLE:
    OFF-ROAD
    PRODUCT NAME:
    PISTON RING
    UNITS:
    SET
    MSRP: $24.95
    Now: $21.00
    Was: $24.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $24.95
    Now: $21.00
    Was: $24.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.4100.B

    PROX Piston Kit 01.4100.B

    PROX

    MSRP: $79.95
    Now: $68.00
    Was: $79.95
    When your engine demands precision and reliability, OEM-quality pistons are non-negotiable. The PROX Piston Kit 01.4100.B delivers factory-spec performance with Japanese engineering and CNC...
    PX4290A
    SKU:
    PX4290A
    Availability:
    Ships Same Business Day
    Weight:
    0.25 LBS
    PISTON DIAMETER METRIC:
    42.96 MM
    PISTON MATERIAL:
    ALUMINUM ALLOY
    PRODUCT NAME:
    PISTON KIT
    UNITS:
    EACH
    BORE SIZE METRIC:
    42.96 MM
    PISTON SIZE METRIC:
    STANDARD SIZE A
    RIDING STYLE:
    OFF-ROAD
    MSRP: $79.95
    Now: $68.00
    Was: $79.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $79.95
    Now: $68.00
    Was: $79.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.4216.A

    PROX Piston Kit 01.4216.A

    PROX

    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    When your engine's pistons wear beyond safe limits, you're looking at catastrophic failure and a complete rebuild. The PROX Piston Kit 01.4216.A restores your engine to OEM-specification performance...
    PX4296A
    SKU:
    PX4296A
    Availability:
    Ships Same Business Day
    Weight:
    0.42 LBS
    PISTON MATERIAL:
    ALUMINUM ALLOY
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    EACH
    BORE SIZE METRIC:
    53.95 MM
    PISTON SIZE METRIC:
    STANDARD SIZE A
    PISTON DIAMETER METRIC:
    53.95 MM
    PRODUCT NAME:
    PISTON KIT
    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.4216.B

    PROX Piston Kit 01.4216.B

    PROX

    MSRP: $121.95
    Now: $90.00
    Was: $121.95
    A worn or damaged piston compromises combustion efficiency, reduces power output, and can lead to catastrophic engine failure. The PROX Piston Kit 01.4216.B delivers OEM-level reliability with...
    PX4296B
    SKU:
    PX4296B
    Availability:
    Ships Same Business Day
    Weight:
    0.38 LBS
    PISTON MATERIAL:
    ALUMINUM ALLOY
    PISTON SIZE METRIC:
    STANDARD SIZE B
    UNITS:
    EACH
    PISTON DIAMETER METRIC:
    53.96 MM
    RIDING STYLE:
    OFF-ROAD
    BORE SIZE METRIC:
    53.96 MM
    PRODUCT NAME:
    PISTON KIT
    MSRP: $121.95
    Now: $90.00
    Was: $121.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $121.95
    Now: $90.00
    Was: $121.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.4216.C

    PROX Piston Kit 01.4216.C

    PROX

    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    When you're rebuilding an engine or replacing worn pistons, you need a drop-in solution that matches OEM performance without compromise. The PROX Piston Kit 01.4216.C delivers exactly...
    PX4296C
    SKU:
    PX4296C
    Availability:
    Ships Same Business Day
    Weight:
    0.38 LBS
    PISTON MATERIAL:
    ALUMINUM ALLOY
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    EACH
    PISTON DIAMETER METRIC:
    53.97 MM
    BORE SIZE METRIC:
    53.97 MM
    PISTON SIZE METRIC:
    STANDARD SIZE C
    PRODUCT NAME:
    PISTON KIT
    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    Subtotal:
  • On Sale
    PROX Ring Set 02.4217

    PROX Ring Set 02.4217

    PROX

    MSRP: $24.95
    Now: $21.00
    Was: $24.95
    Maintaining proper ring seal is critical to engine efficiency, compression, and longevity. The PROX Ring Set 02.4217 delivers OEM-equivalent performance with Japanese manufacturing precision,...
    PX4296R
    SKU:
    PX4296R
    Availability:
    Ships Same Business Day
    Weight:
    0.05 LBS
    UNITS:
    SET
    PISTON MATERIAL:
    ALUMINUM ALLOY
    PRODUCT NAME:
    PISTON RING
    RIDING STYLE:
    OFF-ROAD
    MSRP: $24.95
    Now: $21.00
    Was: $24.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $24.95
    Now: $21.00
    Was: $24.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.4218.A

    PROX Piston Kit 01.4218.A

    PROX

    MSRP: $121.95
    Now: $90.00
    Was: $121.95
    A piston kit is the heart of your engine's combustion cycle—worn or damaged pistons directly compromise compression, power delivery, and engine longevity. The PROX Piston Kit 01.4218.A delivers...
    PX4299A
    SKU:
    PX4299A
    Availability:
    Ships Same Business Day
    Weight:
    0.50 LBS
    BORE SIZE METRIC:
    53.96 MM
    PISTON SIZE METRIC:
    STANDARD SIZE A
    PRODUCT NAME:
    PISTON KIT
    RIDING STYLE:
    OFF-ROAD
    PISTON DIAMETER METRIC:
    53.96 MM
    PISTON MATERIAL:
    ALUMINUM ALLOY
    UNITS:
    EACH
    MSRP: $121.95
    Now: $90.00
    Was: $121.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $121.95
    Now: $90.00
    Was: $121.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.4218.C

    PROX Piston Kit 01.4218.C

    PROX

    MSRP: $121.95
    Now: $90.00
    Was: $121.95
    Your engine's power delivery and longevity depend on piston quality—and factory replacements often compromise on durability or precision. The PROX Piston Kit 01.4218.C delivers OEM-equivalent...
    PX4299C
    SKU:
    PX4299C
    Availability:
    Ships Same Business Day
    Weight:
    0.42 LBS
    PRODUCT NAME:
    PISTON KIT
    BORE SIZE METRIC:
    53.98 MM
    PISTON SIZE METRIC:
    STANDARD SIZE C
    RIDING STYLE:
    OFF-ROAD
    PISTON DIAMETER METRIC:
    53.98 MM
    PISTON MATERIAL:
    ALUMINUM ALLOY
    UNITS:
    EACH
    MSRP: $121.95
    Now: $90.00
    Was: $121.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $121.95
    Now: $90.00
    Was: $121.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.4322.B

    PROX Piston Kit 01.4322.B

    PROX

    MSRP: $143.95
    Now: $119.00
    Was: $143.95
    A worn or damaged piston compromises combustion efficiency, power delivery, and engine longevity. The PROX Piston Kit 01.4322.B restores OEM-level performance with precision-engineered components...
    PX4308B
    SKU:
    PX4308B
    Availability:
    Ships Same Business Day
    Weight:
    0.75 LBS
    PISTON DIAMETER METRIC:
    66.35 MM
    PISTON MATERIAL:
    ALUMINUM ALLOY
    PRODUCT NAME:
    PISTON KIT
    BORE SIZE METRIC:
    66.35 MM
    UNITS:
    EACH
    PISTON SIZE METRIC:
    STANDARD SIZE B
    RIDING STYLE:
    OFF-ROAD
    MSRP: $143.95
    Now: $119.00
    Was: $143.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $143.95
    Now: $119.00
    Was: $143.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.4322.C

    PROX Piston Kit 01.4322.C

    PROX

    MSRP: $143.95
    Now: $119.00
    Was: $143.95
    A piston kit is the heart of your engine's combustion chamber—when yours shows wear, blow-by, or loss of compression, replacement becomes non-negotiable for reliable performance. The PROX Piston Kit...
    PX4308C
    SKU:
    PX4308C
    Availability:
    Ships Same Business Day
    Weight:
    0.75 LBS
    PISTON DIAMETER METRIC:
    66.36 MM
    PISTON SIZE METRIC:
    STANDARD SIZE C
    PRODUCT NAME:
    PISTON KIT
    UNITS:
    EACH
    BORE SIZE METRIC:
    66.36 MM
    PISTON MATERIAL:
    ALUMINUM ALLOY
    RIDING STYLE:
    OFF-ROAD
    MSRP: $143.95
    Now: $119.00
    Was: $143.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $143.95
    Now: $119.00
    Was: $143.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.4285.A

    PROX Piston Kit 01.4285.A

    PROX

    MSRP: $132.95
    Now: $110.00
    Was: $132.95
    When your engine's factory pistons show wear or you're rebuilding after high-mileage use, settling for inferior replacements compromises reliability and performance. The PROX Piston Kit 01.4285.A...
    PX4310A
    SKU:
    PX4310A
    Availability:
    Ships Same Business Day
    Weight:
    0.55 LBS
    PISTON MATERIAL:
    ALUMINUM ALLOY
    UNITS:
    EACH
    PISTON DIAMETER METRIC:
    65.94 MM
    RIDING STYLE:
    OFF-ROAD
    BORE SIZE METRIC:
    65.94 MM
    PISTON SIZE METRIC:
    STANDARD SIZE A
    PRODUCT NAME:
    PISTON KIT
    MSRP: $132.95
    Now: $110.00
    Was: $132.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $132.95
    Now: $110.00
    Was: $132.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.4285.B

    PROX Piston Kit 01.4285.B

    PROX

    MSRP: $132.95
    Now: $110.00
    Was: $132.95
    When your engine's internals are worn or damaged, a quality piston kit is non-negotiable for restoring reliable power and compression. The PROX Piston Kit 01.4285.B delivers OEM-grade performance...
    PX4310B
    SKU:
    PX4310B
    Availability:
    Ships Same Business Day
    Weight:
    0.60 LBS
    PISTON DIAMETER METRIC:
    65.95 MM
    RIDING STYLE:
    OFF-ROAD
    PISTON MATERIAL:
    ALUMINUM ALLOY
    UNITS:
    EACH
    PISTON SIZE METRIC:
    STANDARD SIZE B
    BORE SIZE METRIC:
    65.95 MM
    PRODUCT NAME:
    PISTON KIT
    MSRP: $132.95
    Now: $110.00
    Was: $132.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $132.95
    Now: $110.00
    Was: $132.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.4285.C

    PROX Piston Kit 01.4285.C

    PROX

    MSRP: $132.95
    Now: $110.00
    Was: $132.95
    A piston kit is fundamental to engine reliability and performance—worn or damaged pistons compromise combustion efficiency, increase blow-by, and risk catastrophic engine failure. The PROX Piston Kit...
    PX4310C
    SKU:
    PX4310C
    Availability:
    Ships Same Business Day
    Weight:
    0.65 LBS
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    EACH
    PRODUCT NAME:
    PISTON KIT
    PISTON DIAMETER METRIC:
    65.96 MM
    BORE SIZE METRIC:
    65.96 MM
    PISTON MATERIAL:
    ALUMINUM ALLOY
    PISTON SIZE METRIC:
    STANDARD SIZE C
    MSRP: $132.95
    Now: $110.00
    Was: $132.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $132.95
    Now: $110.00
    Was: $132.95
    Subtotal:
  • On Sale
    PROX Ring Set 02.4285

    PROX Ring Set 02.4285

    PROX

    MSRP: $44.95
    Now: $38.00
    Was: $44.95
    Piston rings are the critical seal between your combustion chamber and crankcase—when they wear, you lose compression, power, and fuel efficiency. The PROX Ring Set 02.4285 delivers OEM-equivalent...
    PX4310R
    SKU:
    PX4310R
    Availability:
    Ships Same Business Day
    Weight:
    0.05 LBS
    PISTON MATERIAL:
    ALUMINUM ALLOY
    PRODUCT NAME:
    PISTON RING
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    SET
    MSRP: $44.95
    Now: $38.00
    Was: $44.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $44.95
    Now: $38.00
    Was: $44.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.4408.A

    PROX Piston Kit 01.4408.A

    PROX

    MSRP: $185.95
    Now: $158.00
    Was: $185.95
    A worn or damaged piston can compromise engine efficiency, increase blow-by, and lead to catastrophic failure if left unaddressed. The PROX Piston Kit 01.4408.A delivers OEM-equivalent performance...
    PX4330A
    SKU:
    PX4330A
    Availability:
    Ships Same Business Day
    Weight:
    1.18 LBS
    RIDING STYLE:
    OFF-ROAD
    PISTON SIZE METRIC:
    STANDARD SIZE A
    PRODUCT NAME:
    PISTON KIT
    BORE SIZE METRIC:
    85.94 MM
    PISTON MATERIAL:
    ALUMINUM ALLOY
    PISTON DIAMETER METRIC:
    85.94 MM
    UNITS:
    EACH
    MSRP: $185.95
    Now: $158.00
    Was: $185.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $185.95
    Now: $158.00
    Was: $185.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.4408.B

    PROX Piston Kit 01.4408.B

    PROX

    MSRP: $185.95
    Now: $158.00
    Was: $185.95
    A worn or damaged piston kit compromises combustion efficiency, reduces power output, and risks catastrophic engine failure. The PROX Piston Kit 01.4408.B delivers OEM-equivalent performance with...
    PX4330B
    SKU:
    PX4330B
    Availability:
    Ships Same Business Day
    Weight:
    1.18 LBS
    PISTON DIAMETER METRIC:
    85.95 MM
    BORE SIZE METRIC:
    85.95 MM
    UNITS:
    EACH
    PISTON MATERIAL:
    ALUMINUM ALLOY
    PRODUCT NAME:
    PISTON KIT
    PISTON SIZE METRIC:
    STANDARD SIZE B
    RIDING STYLE:
    OFF-ROAD
    MSRP: $185.95
    Now: $158.00
    Was: $185.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $185.95
    Now: $158.00
    Was: $185.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.1315.A

    PROX Piston Kit 01.1315.A

    PROX

    MSRP: $139.95
    Now: $119.00
    Was: $139.95
    A piston kit is your foundation for reliable engine performance and longevity. The PROX Piston Kit 01.1315.A delivers OEM-equivalent quality with precision engineering that ensures proper ring...
    PX4420A
    SKU:
    PX4420A
    Availability:
    Ships Same Business Day
    Weight:
    0.63 LBS
    PISTON MATERIAL:
    ALUMINUM ALLOY
    UNITS:
    EACH
    BORE SIZE METRIC:
    66.34 MM
    PISTON SIZE METRIC:
    STANDARD SIZE A
    RIDING STYLE:
    OFF-ROAD
    PISTON DIAMETER METRIC:
    66.34 MM
    PRODUCT NAME:
    PISTON KIT
    MSRP: $139.95
    Now: $119.00
    Was: $139.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $139.95
    Now: $119.00
    Was: $139.95
    Subtotal:
  • On Sale
    PROX Ring Set 02.1315

    PROX Ring Set 02.1315

    PROX

    MSRP: $49.95
    Now: $42.00
    Was: $49.95
    Worn piston rings directly compromise combustion efficiency, oil consumption, and overall engine reliability—making a quality replacement essential for consistent performance. The PROX Ring Set 02...
    PX4420R
    SKU:
    PX4420R
    Availability:
    Ships Same Business Day
    Weight:
    0.05 LBS
    PRODUCT NAME:
    PISTON RING
    UNITS:
    SET
    RIDING STYLE:
    OFF-ROAD
    PISTON MATERIAL:
    ALUMINUM ALLOY
    MSRP: $49.95
    Now: $42.00
    Was: $49.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $49.95
    Now: $42.00
    Was: $49.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.1320.A

    PROX Piston Kit 01.1320.A

    PROX

    MSRP: $143.95
    Now: $119.00
    Was: $143.95
    Your engine's performance and longevity depend on pistons that can withstand extreme temperatures, pressures, and RPMs without compromise. The PROX Piston Kit 01.1320.A is engineered as a direct OEM...
    PX4430A
    SKU:
    PX4430A
    Availability:
    Ships Same Business Day
    Weight:
    0.63 LBS
    RIDING STYLE:
    OFF-ROAD
    BORE SIZE METRIC:
    66.34 MM
    PISTON DIAMETER METRIC:
    66.34 MM
    PISTON SIZE METRIC:
    STANDARD SIZE A
    PRODUCT NAME:
    PISTON KIT
    PISTON MATERIAL:
    ALUMINUM ALLOY
    UNITS:
    EACH
    MSRP: $143.95
    Now: $119.00
    Was: $143.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $143.95
    Now: $119.00
    Was: $143.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.1320.A1

    PROX Piston Kit 01.1320.A1

    PROX

    MSRP: $143.95
    Now: $119.00
    Was: $143.95
    When your engine demands reliable power delivery and long-term durability, stock pistons often fall short of performance expectations. The PROX Piston Kit 01.1320.A1 delivers OEM-equivalent quality...
    PX4430B
    SKU:
    PX4430B
    Availability:
    Ships Same Business Day
    Weight:
    0.75 LBS
    PISTON DIAMETER METRIC:
    66.34 MM
    PISTON SIZE METRIC:
    STANDARD SIZE A
    BORE SIZE METRIC:
    66.35 MM
    PRODUCT NAME:
    PISTON KIT
    PISTON MATERIAL:
    ALUMINUM ALLOY
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    EACH
    MSRP: $143.95
    Now: $119.00
    Was: $143.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $143.95
    Now: $119.00
    Was: $143.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.2660.000

    PROX Piston Kit 01.2660.000

    PROX

    MSRP: $155.95
    Now: $119.00
    Was: $155.95
    When your engine's pistons show wear, you're losing compression, efficiency, and power—and risking catastrophic failure. The PROX Piston Kit 01.2660.000 is engineered to OEM specifications using...
    PX4670
    SKU:
    PX4670
    Availability:
    Ships Same Business Day
    Weight:
    1.34 LBS
    PISTON MATERIAL:
    ALUMINUM ALLOY
    ENGINE TYPE:
    4-STROKE
    RIDING STYLE:
    ATV
    UNITS:
    EACH
    PISTON DIAMETER METRIC:
    100.00 MM
    BORE SIZE METRIC:
    100.00 MM
    PISTON SIZE METRIC:
    STANDARD
    PRODUCT NAME:
    PISTON KIT
    RIDING STYLE:
    UTV
    MSRP: $155.95
    Now: $119.00
    Was: $155.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $155.95
    Now: $119.00
    Was: $155.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.2660.050

    PROX Piston Kit 01.2660.050

    PROX

    MSRP: $155.95
    Now: $119.00
    Was: $155.95
    When your engine demands precision and reliability, OEM-quality pistons are non-negotiable. The PROX Piston Kit 01.2660.050 delivers Japanese manufacturing excellence with high-silicon aluminum...
    PX4672
    SKU:
    PX4672
    Availability:
    Ships Same Business Day
    Weight:
    1.36 LBS
    BORE SIZE METRIC:
    100.50 MM
    ENGINE TYPE:
    4-STROKE
    PISTON DIAMETER METRIC:
    100.50 MM
    PISTON MATERIAL:
    ALUMINUM ALLOY
    PISTON SIZE METRIC:
    +0.50 MM
    RIDING STYLE:
    ATV
    UNITS:
    EACH
    PRODUCT NAME:
    PISTON KIT
    RIDING STYLE:
    UTV
    MSRP: $155.95
    Now: $119.00
    Was: $155.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $155.95
    Now: $119.00
    Was: $155.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.2660.100

    PROX Piston Kit 01.2660.100

    PROX

    MSRP: $139.95
    Now: $119.00
    Was: $139.95
    When your engine demands reliability at high RPM, OEM-spec pistons are non-negotiable. The PROX Piston Kit 01.2660.100 delivers factory-engineered performance with the precision tolerances required...
    PX4674
    SKU:
    PX4674
    Availability:
    Ships Same Business Day
    Weight:
    1.38 LBS
    BORE SIZE METRIC:
    101.00 MM
    RIDING STYLE:
    UTV
    PISTON MATERIAL:
    ALUMINUM ALLOY
    ENGINE TYPE:
    4-STROKE
    PISTON SIZE METRIC:
    +1.00 MM
    PRODUCT NAME:
    PISTON KIT
    RIDING STYLE:
    ATV
    UNITS:
    EACH
    PISTON DIAMETER METRIC:
    101.00 MM
    MSRP: $139.95
    Now: $119.00
    Was: $139.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $139.95
    Now: $119.00
    Was: $139.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.3214.B

    PROX Piston Kit 01.3214.B

    PROX

    MSRP: $121.95
    Now: $90.00
    Was: $121.95
    When your engine demands reliability under extreme conditions, OEM-equivalent performance becomes non-negotiable. The PROX Piston Kit 01.3214.B delivers Japanese manufacturing precision with...
    PX5050B
    SKU:
    PX5050B
    Availability:
    Ships Same Business Day
    Weight:
    0.44 LBS
    PISTON MATERIAL:
    ALUMINUM ALLOY
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    EACH
    PISTON SIZE METRIC:
    STANDARD SIZE B
    BORE SIZE METRIC:
    53.95 MM
    PISTON DIAMETER METRIC:
    53.95 MM
    PRODUCT NAME:
    PISTON KIT
    MSRP: $121.95
    Now: $90.00
    Was: $121.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $121.95
    Now: $90.00
    Was: $121.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.3214.C

    PROX Piston Kit 01.3214.C

    PROX

    MSRP: $121.95
    Now: $90.00
    Was: $121.95
    A piston kit is fundamental to engine reliability and performance—worn or damaged pistons compromise compression, increase blowby, and risk catastrophic engine failure. The PROX Piston Kit 01.3214.C...
    PX5050C
    SKU:
    PX5050C
    Availability:
    Ships Same Business Day
    Weight:
    0.44 LBS
    UNITS:
    EACH
    PISTON DIAMETER METRIC:
    53.96 MM
    PISTON MATERIAL:
    ALUMINUM ALLOY
    PISTON SIZE METRIC:
    STANDARD SIZE C
    RIDING STYLE:
    OFF-ROAD
    BORE SIZE METRIC:
    53.96 MM
    PRODUCT NAME:
    PISTON KIT
    MSRP: $121.95
    Now: $90.00
    Was: $121.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $121.95
    Now: $90.00
    Was: $121.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.3214.D

    PROX Piston Kit 01.3214.D

    PROX

    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    A failed or worn piston compromises combustion efficiency, power delivery, and engine reliability. The PROX Piston Kit 013214D delivers OEM-equivalent performance with precision manufacturing that...
    PX5050D
    SKU:
    PX5050D
    Availability:
    Ships Same Business Day
    Weight:
    0.44 LBS
    BORE SIZE METRIC:
    53.97 MM
    PISTON DIAMETER METRIC:
    53.97 MM
    PISTON SIZE METRIC:
    STANDARD SIZE D
    RIDING STYLE:
    OFF-ROAD
    PISTON MATERIAL:
    ALUMINUM ALLOY
    UNITS:
    EACH
    PRODUCT NAME:
    PISTON KIT
    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    Subtotal:
  • On Sale
    PROX Ring Set 02.3212

    PROX Ring Set 02.3212

    PROX

    MSRP: $24.95
    Now: $21.00
    Was: $24.95
    Piston rings are critical to engine sealing and compression—worn or damaged rings lead to blow-by, oil consumption, and power loss. The PROX Ring Set 02.3212 delivers OEM-equivalent performance with...
    PX5050R
    SKU:
    PX5050R
    Availability:
    Ships Same Business Day
    Weight:
    0.02 LBS
    PISTON MATERIAL:
    ALUMINUM ALLOY
    RIDING STYLE:
    OFF-ROAD
    PRODUCT NAME:
    PISTON RING
    UNITS:
    SET
    MSRP: $24.95
    Now: $21.00
    Was: $24.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $24.95
    Now: $21.00
    Was: $24.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.3220.A

    PROX Piston Kit 01.3220.A

    PROX

    MSRP: $121.95
    Now: $87.00
    Was: $121.95
    Your engine's pistons are the hardworking heart of combustion—and when they wear, performance suffers. The PROX Piston Kit 01.3220.A restores your engine to OEM specifications with...
    PX5060A
    SKU:
    PX5060A
    Availability:
    Ships Same Business Day
    Weight:
    0.42 LBS
    PISTON DIAMETER METRIC:
    53.94 MM
    PISTON MATERIAL:
    ALUMINUM ALLOY
    PRODUCT NAME:
    PISTON KIT
    UNITS:
    EACH
    BORE SIZE METRIC:
    53.94 MM
    PISTON SIZE METRIC:
    STANDARD SIZE A
    RIDING STYLE:
    OFF-ROAD
    MSRP: $121.95
    Now: $87.00
    Was: $121.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $121.95
    Now: $87.00
    Was: $121.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.3220.B

    PROX Piston Kit 01.3220.B

    PROX

    MSRP: $101.95
    Now: $87.00
    Was: $101.95
    A worn or damaged piston directly compromises engine compression, power output, and fuel efficiency—making a quality replacement essential for reliable performance. The PROX Piston Kit 01.3220.B...
    PX5060B
    SKU:
    PX5060B
    Availability:
    Ships Same Business Day
    Weight:
    0.42 LBS
    BORE SIZE METRIC:
    53.95 MM
    PISTON SIZE METRIC:
    STANDARD SIZE B
    PISTON MATERIAL:
    ALUMINUM ALLOY
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    EACH
    PISTON DIAMETER METRIC:
    53.95 MM
    PRODUCT NAME:
    PISTON KIT
    MSRP: $101.95
    Now: $87.00
    Was: $101.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $101.95
    Now: $87.00
    Was: $101.95
    Subtotal:
  • On Sale
    PROX Piston Kit 01.3220.C

    PROX Piston Kit 01.3220.C

    PROX

    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    Your engine's ability to handle sustained RPMs and maintain combustion efficiency depends entirely on piston quality—worn or substandard pistons lead to blow-by, compression loss, and catastrophic...
    PX5060C
    SKU:
    PX5060C
    Availability:
    Ships Same Business Day
    Weight:
    0.42 LBS
    PISTON DIAMETER METRIC:
    53.96 MM
    PISTON MATERIAL:
    ALUMINUM ALLOY
    PISTON SIZE METRIC:
    STANDARD SIZE C
    RIDING STYLE:
    OFF-ROAD
    UNITS:
    EACH
    BORE SIZE METRIC:
    53.96 MM
    PRODUCT NAME:
    PISTON KIT
    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $105.95
    Now: $90.00
    Was: $105.95
    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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