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Dirt Bike Piston and Ring Kits

Dirt Bike Piston and Ring Kits

Dirt Bike Piston and Ring Kits

Dirt Bike Piston & Ring Kits for Yamaha YZ85, WR250 & YZ250 at JJ Motorsports

Rebuild your dirt bike's top end for maximum power and reliability with premium piston and ring kits from JJ Motorsports, forged from high-strength aluminum for superior heat resistance, lightweight performance, and precise fit in motocross, enduro, and trail riding. Our selection includes complete kits with pistons, high-performance rings, wrist pins, circlips, top-end bearings, and gaskets designed for enhanced combustion efficiency, reduced blow-by, and longer engine life under high-RPM abuse. Compatible with popular models like Yamaha YZ85 (2002-2018), WR250, and YZ250, these Wiseco-engineered components feature CNC-machined crowns for optimal cam shape, ArmorGlide skirt coatings for low friction, and 4032 alloy construction for durability in dusty, aggressive conditions. Whether you're refreshing a youth 85cc 2-stroke or upgrading a 250cc big bore, these kits ensure crisp throttle response, better sealing, and race-ready power without the need for custom boring—perfect for DIY rebuilds or pro-level maintenance.

Shop trusted brands like Wiseco for race-proven quality. Explore related categories such as dirt bike engine for cylinders and valves or dirt bike air and fuel for carburetors and jets.

Top Dirt Bike Piston & Ring Kits

Browse our in-stock inventory below with same-day shipping and expert support. Free shipping on orders over $99! Questions? Contact us for fitment advice!

  • Product
  • Qty in Cart
  • Quantity
  • Price
  • Subtotal
  • On Sale
    PROX Piston Kit - 77.96 mm - Kawasaki KX250/KX250X 01.4353.A

    PROX Piston Kit - 77.96 mm - Kawasaki KX250/KX250X 01.4353.A

    PROX

    MSRP: $188.95
    Now: $158.00
    Was: $188.95
    Piston Kit - 77.96 mm - Kawasaki KX250/KX250X Kit includes piston, rings, wrist pin, circlips and instruction sheet, The piston is precision machined on state of the art CNC equipment, Piston rings are made by OEM factories to exact specifications
    09106787
    SKU:
    09106787
    Availability:
    Ships Same Business Day
    Weight:
    0.50 LBS
    MSRP: $188.95
    Now: $158.00
    Was: $188.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $188.95
    Now: $158.00
    Was: $188.95
    Subtotal:
  • On Sale
    PROX Piston Kit - 57.94 mm - Husqvarna TE150i | KTM 150EXC TPI 01.6241.A

    PROX Piston Kit - 57.94 mm - Husqvarna TE150i | KTM 150EXC TPI 01.6241.A

    PROX

    MSRP: $139.95
    Now: $119.00
    Was: $139.95
    Piston Kit - 57.94 mm - Husqvarna TE150i | KTM 150EXC TPI Manufactured in Japan and designed to be OEM replacement, Cast from a high-silicon-content aluminum alloy that meets or exceeds OEM specifications, then CNC-machined to extremely close tolerances,...
    09106792
    SKU:
    09106792
    Availability:
    Ships Same Business Day
    Weight:
    0.50 LBS
    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 - 87.96 mm - Gas Gas | Husqvarna | KTM 01.6353.A

    PROX Piston Kit - 87.96 mm - Gas Gas | Husqvarna | KTM 01.6353.A

    PROX

    MSRP: $209.95
    Now: $195.00
    Was: $229.73
    Piston Kit - 87.96 mm - Gas Gas | Husqvarna | KTM Kit includes piston, rings, wrist pin, circlips and instruction sheet, The piston is precision machined on state of the art CNC equipment, Piston rings are made by OEM factories to exact specifications
    09106793
    SKU:
    09106793
    Availability:
    Ships Same Business Day
    Weight:
    0.45 LBS
    MSRP: $209.95
    Now: $195.00
    Was: $229.73
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $209.95
    Now: $195.00
    Was: $229.73
    Subtotal:
  • On Sale
    PROX Piston Kit - 94.95 mm - Gas Gas | Husqvarna | KTM 01.6434.A

    PROX Piston Kit - 94.95 mm - Gas Gas | Husqvarna | KTM 01.6434.A

    PROX

    MSRP: $221.95
    Now: $183.00
    Was: $221.95
    Piston Kit - 94.95 mm - Gas Gas | Husqvarna | KTM Kit includes piston, rings, wrist pin, circlips and instruction sheet, The piston is precision machined on state of the art CNC equipment, Piston rings are made by OEM factories to exact specifications
    09106794
    SKU:
    09106794
    Availability:
    Ships Same Business Day
    Weight:
    1.00 LBS
    MSRP: $221.95
    Now: $183.00
    Was: $221.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $221.95
    Now: $183.00
    Was: $221.95
    Subtotal:
  • On Sale
    PROX Piston Kit - 94.95 mm - Husqvarna FE450 | KTM 450EXC-F 01.6440.A

    PROX Piston Kit - 94.95 mm - Husqvarna FE450 | KTM 450EXC-F 01.6440.A

    PROX

    MSRP: $221.95
    Now: $167.00
    Was: $221.95
    Piston Kit - 94.95 mm - Husqvarna FE450 | KTM 450EXC-F Kit includes piston, rings, wrist pin, circlips and instruction sheet, The piston is precision machined on state of the art CNC equipment, Piston rings are made by OEM factories to exact...
    09106795
    SKU:
    09106795
    Availability:
    Ships Same Business Day
    Weight:
    0.50 LBS
    MSRP: $221.95
    Now: $167.00
    Was: $221.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $221.95
    Now: $167.00
    Was: $221.95
    Subtotal:
  • On Sale
    PROX Piston Kit - 94.96 mm - Gas Gas | Husqvarna | KTM 01.6443.A

    PROX Piston Kit - 94.96 mm - Gas Gas | Husqvarna | KTM 01.6443.A

    PROX

    MSRP: $214.95
    Now: $183.00
    Was: $214.95
    Piston Kit - 94.96 mm - Gas Gas | Husqvarna | KTM Kit includes piston, rings, wrist pin, circlips and instruction sheet, The piston is precision machined on state of the art CNC equipment, Piston rings are made by OEM factories to exact specifications
    09106796
    SKU:
    09106796
    Availability:
    Ships Same Business Day
    Weight:
    0.83 LBS
    MSRP: $214.95
    Now: $183.00
    Was: $214.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $214.95
    Now: $183.00
    Was: $214.95
    Subtotal:
  • On Sale
    PROX Piston Kit - 94.95 mm - Gas Gas | Husqvarna | KTM 01.6513.A

    PROX Piston Kit - 94.95 mm - Gas Gas | Husqvarna | KTM 01.6513.A

    PROX

    MSRP: $221.95
    Now: $183.00
    Was: $221.95
    Piston Kit - 94.95 mm - 01.6513.A High-performance piston kit designed for Gas Gas, Husqvarna, and KTM motorcycles. Includes all essential components: piston, rings, wrist pin, circlips, and instruction sheet. Precision machined using...
    09106797
    SKU:
    09106797
    Availability:
    Ships Same Business Day
    Weight:
    0.78 LBS
    MSRP: $221.95
    Now: $183.00
    Was: $221.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $221.95
    Now: $183.00
    Was: $221.95
    Subtotal:
  • On Sale
    PROX Piston Kit - 66.34 mm - Beta RR250/Xtrainer 250 01.7313.A

    PROX Piston Kit - 66.34 mm - Beta RR250/Xtrainer 250 01.7313.A

    PROX

    MSRP: $159.95
    Now: $136.00
    Was: $159.95
    Piston Kit - 66.34 mm - Beta RR250/Xtrainer 250 Manufactured in Japan and designed to be OEM replacement, Cast from a high-silicon-content aluminum alloy that meets or exceeds OEM specifications, then CNC-machined to extremely close tolerances, Kit...
    09106798
    SKU:
    09106798
    Availability:
    Ships Same Business Day
    Weight:
    0.75 LBS
    MSRP: $159.95
    Now: $136.00
    Was: $159.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $159.95
    Now: $136.00
    Was: $159.95
    Subtotal:
  • On Sale
    PROX Piston Kit - 75.96 mm - Sherco 250SE-F/250SEF-R 01.7314.A

    PROX Piston Kit - 75.96 mm - Sherco 250SE-F/250SEF-R 01.7314.A

    PROX

    MSRP: $209.99
    Now: $178.00
    Was: $209.99
    Piston Kit - 75.96 mm - Sherco 250SE-F/250SEF-R Kit includes piston, rings, wrist pin, circlips and instruction sheet, The piston is precision machined on state of the art CNC equipment, Piston rings are made by OEM factories to exact specifications
    09106799
    SKU:
    09106799
    Availability:
    Ships Same Business Day
    Weight:
    0.50 LBS
    MSRP: $209.99
    Now: $178.00
    Was: $209.99
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $209.99
    Now: $178.00
    Was: $209.99
    Subtotal:
  • On Sale
    PROX Piston Kit - 83.95 mm - Sherco 300SE-F/300SEF-R 01.7324.A

    PROX Piston Kit - 83.95 mm - Sherco 300SE-F/300SEF-R 01.7324.A

    PROX

    MSRP: $221.95
    Now: $178.00
    Was: $221.95
    Piston Kit - 83.95 mm - Sherco 300SE-F/300SEF-R Kit includes piston, rings, wrist pin, circlips and instruction sheet, The piston is precision machined on state of the art CNC equipment, Piston rings are made by OEM factories to exact specifications
    09106800
    SKU:
    09106800
    Availability:
    Ships Same Business Day
    Weight:
    0.40 LBS
    MSRP: $221.95
    Now: $178.00
    Was: $221.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $221.95
    Now: $178.00
    Was: $221.95
    Subtotal:
  • On Sale
    PROX Piston Kit - 66.34 mm - Sherco 250SE/250SE-R 01.7334.A

    PROX Piston Kit - 66.34 mm - Sherco 250SE/250SE-R 01.7334.A

    PROX

    MSRP: $166.95
    Now: $136.00
    Was: $166.95
    Piston Kit - 66.34 mm - 01.7334.A OEM replacement designed specifically for Sherco 250SE/250SE-R models. Manufactured in Japan for superior quality and reliability. Crafted from high-silicon-content aluminum alloy for enhanced durability. ...
    09106801
    SKU:
    09106801
    Availability:
    Ships Same Business Day
    Weight:
    0.70 LBS
    MSRP: $166.95
    Now: $136.00
    Was: $166.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $166.95
    Now: $136.00
    Was: $166.95
    Subtotal:
  • On Sale
    PROX Piston Kit - 66.34 mm - Sherco 250SE/250SE-R 01.7337.A

    PROX Piston Kit - 66.34 mm - Sherco 250SE/250SE-R 01.7337.A

    PROX

    MSRP: $166.95
    Now: $136.00
    Was: $166.95
    Piston Kit - 66.34 mm - Sherco 250SE/250SE-R 01.7337.A Precision-engineered for perfect fit and performance. Manufactured in Japan ensuring high-quality standards. Made from high-silicon-content aluminum alloy for durability. ...
    09106802
    SKU:
    09106802
    Availability:
    Ships Same Business Day
    Weight:
    0.50 LBS
    MSRP: $166.95
    Now: $136.00
    Was: $166.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $166.95
    Now: $136.00
    Was: $166.95
    Subtotal:
  • On Sale
    PROX Piston Kit - 71.94 mm - Sherco 300SE/300SE-R 01.7346.A

    PROX Piston Kit - 71.94 mm - Sherco 300SE/300SE-R 01.7346.A

    PROX

    MSRP: $221.95
    Now: $170.00
    Was: $221.95
    Piston Kit - 71.94 mm - Sherco 300SE/300SE-R Manufactured in Japan and designed to be OEM replacement, Cast from a high-silicon-content aluminum alloy that meets or exceeds OEM specifications, then CNC-machined to extremely close tolerances, Kit includes...
    09106803
    SKU:
    09106803
    Availability:
    Ships Same Business Day
    Weight:
    0.80 LBS
    MSRP: $221.95
    Now: $170.00
    Was: $221.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $221.95
    Now: $170.00
    Was: $221.95
    Subtotal:
  • On Sale
    PROX Piston Kit - 87.96 mm - Beta 350RR 01.7351.A

    PROX Piston Kit - 87.96 mm - Beta 350RR 01.7351.A

    PROX

    MSRP: $221.95
    Now: $178.00
    Was: $221.95
    Piston Kit - 87.96 mm - 01.7351.A Precision machined for optimal performance Includes piston, rings, wrist pin, and circlips OEM-quality piston rings made to exact specifications Comprehensive instruction sheet for easy installation ...
    09106804
    SKU:
    09106804
    Availability:
    Ships Same Business Day
    Weight:
    0.69 LBS
    MSRP: $221.95
    Now: $178.00
    Was: $221.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $221.95
    Now: $178.00
    Was: $221.95
    Subtotal:
  • On Sale
    PROX Piston Kit - 87.96 mm - Beta 350RR 01.7355.A

    PROX Piston Kit - 87.96 mm - Beta 350RR 01.7355.A

    PROX

    MSRP: $221.95
    Now: $178.00
    Was: $221.95
    Piston Kit - 87.96 mm - 01.7355.A High-performance piston kit designed for Beta 350RR. Includes piston, rings, wrist pin, circlips, and detailed instruction sheet. Precision machined using advanced CNC technology for optimal performance. ...
    09106805
    SKU:
    09106805
    Availability:
    Ships Same Business Day
    Weight:
    0.75 LBS
    MSRP: $221.95
    Now: $178.00
    Was: $221.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $221.95
    Now: $178.00
    Was: $221.95
    Subtotal:
  • On Sale
    PROX Piston Kit - 87.96 mm - Beta 390RR 01.7365.A

    PROX Piston Kit - 87.96 mm - Beta 390RR 01.7365.A

    PROX

    MSRP: $221.95
    Now: $183.00
    Was: $221.95
    Piston Kit - 87.96 mm - Beta 390RR Kit includes piston, rings, wrist pin, circlips and instruction sheet, The piston is precision machined on state of the art CNC equipment, Piston rings are made by OEM factories to exact specifications
    09106806
    SKU:
    09106806
    Availability:
    Ships Same Business Day
    Weight:
    0.45 LBS
    MSRP: $221.95
    Now: $183.00
    Was: $221.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $221.95
    Now: $183.00
    Was: $221.95
    Subtotal:
  • On Sale
    PROX Piston Kit - 94.95 mm - Beta 400RR 01.7411.A

    PROX Piston Kit - 94.95 mm - Beta 400RR 01.7411.A

    PROX

    MSRP: $216.95
    Now: $183.00
    Was: $216.95
    Piston Kit - 94.95 mm - Beta 400RR Kit includes piston, rings, wrist pin, circlips and instruction sheet, The piston is precision machined on state of the art CNC equipment, Piston rings are made by OEM factories to exact specifications
    09106808
    SKU:
    09106808
    Availability:
    Ships Same Business Day
    Weight:
    0.60 LBS
    MSRP: $216.95
    Now: $183.00
    Was: $216.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $216.95
    Now: $183.00
    Was: $216.95
    Subtotal:
  • On Sale
    PROX Piston Kit - 94.95 mm - Beta 450RR 01.7412.A

    PROX Piston Kit - 94.95 mm - Beta 450RR 01.7412.A

    PROX

    MSRP: $221.95
    Now: $183.00
    Was: $221.95
    Piston Kit - 94.95 mm - Beta 450RR Kit includes piston, rings, wrist pin, circlips and instruction sheet, The piston is precision machined on state of the art CNC equipment, Piston rings are made by OEM factories to exact specifications
    09106809
    SKU:
    09106809
    Availability:
    Ships Same Business Day
    Weight:
    0.85 LBS
    MSRP: $221.95
    Now: $183.00
    Was: $221.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $221.95
    Now: $183.00
    Was: $221.95
    Subtotal:
  • On Sale
    PROX Piston Kit - 94.96 mm - Beta 430RR 01.7415.A

    PROX Piston Kit - 94.96 mm - Beta 430RR 01.7415.A

    PROX

    MSRP: $216.95
    Now: $183.00
    Was: $216.95
    Piston Kit - 94.96 mm - Beta 430RR Kit includes piston, rings, wrist pin, circlips and instruction sheet, The piston is precision machined on state of the art CNC equipment, Piston rings are made by OEM factories to exact specifications
    09106811
    SKU:
    09106811
    Availability:
    Ships Same Business Day
    Weight:
    0.50 LBS
    MSRP: $216.95
    Now: $183.00
    Was: $216.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $216.95
    Now: $183.00
    Was: $216.95
    Subtotal:
  • On Sale
    PROX Piston Kit - 99.96 mm - Beta 480RR 01.7425.A

    PROX Piston Kit - 99.96 mm - Beta 480RR 01.7425.A

    PROX

    MSRP: $221.95
    Now: $183.00
    Was: $221.95
    Piston Kit - 99.96 mm - Beta 480RR Kit includes piston, rings, wrist pin, circlips and instruction sheet, The piston is precision machined on state of the art CNC equipment, Piston rings are made by OEM factories to exact specifications
    09106812
    SKU:
    09106812
    Availability:
    Ships Same Business Day
    Weight:
    0.85 LBS
    MSRP: $221.95
    Now: $183.00
    Was: $221.95
    Qty in Cart: 0
    Quantity:
    Price:
    MSRP: $221.95
    Now: $183.00
    Was: $221.95
    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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