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
- Wiseco YZ85 2002-2018 Piston Kit with Gaskets PK1202 – 47.50mm forged aluminum piston kit for Yamaha YZ85 2-stroke; includes rings, wrist pin, circlips, bearing, and gaskets for enhanced combustion and throttle response.
- Wiseco 68.00mm Piston Kit with Gaskets Yamaha WR/YZ 250 PK1563 – Complete big bore kit for Yamaha WR250/YZ250; features forged piston, rings, wrist pin, circlips, and top-end gaskets for superior power and sealing.
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
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Wossner Piston Kit 62.02 mm Beta RR 200 2019-2024 8325DC
WOSSNER
$142.00Stock pistons accumulate carbon deposits and wear unevenly—especially in high-demand applications like the Beta RR 200. This Wossner kit replaces worn components with aerospace-grade aluminum and a permanent skirt coating that actively reduces friction,...09106634- SKU:
- 09106634
- Availability:
- Ships Same Business Day
- Weight:
- 0.60 LBS
$142.00 -
Wossner Piston Kit 53.95mm Yamaha YZ125 2005-2021 8302DA
WOSSNER
$132.00The stock piston in your YZ125 is subject to constant thermal stress and detonation cycles that accelerate wear—especially if you're pushing higher RPMs or running aggressive jetting. A quality replacement piston kit restores compression, eliminates ring...09106635- SKU:
- 09106635
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
$132.00 -
Wossner Piston Kit 53.96mm Yamaha YZ125 2005-2021 8302DB
WOSSNER
$132.00If you're running a YZ125 and looking to maximize power delivery and engine longevity, a quality piston kit is non-negotiable. Wossner's 53.96mm piston combines precision engineering with proven durability, giving you the reliability to push harder on...09106636- SKU:
- 09106636
- Availability:
- Ships Same Business Day
- Weight:
- 0.46 LBS
$132.00 -
Wossner Piston Kit 53.97mm Yamaha YZ125 2005-2021 8302DC
WOSSNER
$132.00A worn or damaged piston directly compromises engine efficiency, power delivery, and longevity—especially critical for YZ125 two-stroke engines where precision tolerances are unforgiving. The Wossner 53.97mm piston kit restores your engine to OEM...09106637- SKU:
- 09106637
- Availability:
- Ships Same Business Day
- Weight:
- 0.46 LBS
$132.00 -
Wossner Piston Kit 53.93mm for Sherco 125 SE-R 2018-2025 8303DA
WOSSNER
$132.00Your Sherco's engine performance depends on a piston that can handle sustained load cycles and elevated combustion pressures without sacrificing reliability. The Wossner 53.93mm piston kit delivers the precision fit and material quality necessary to...09106638- SKU:
- 09106638
- Availability:
- Ships Same Business Day
- Weight:
- 0.48 LBS
$132.00 -
Wossner Piston Kit 53.94 mm Sherco 125 SE-R 2018-2025 8303DB
WOSSNER
$132.00When your Sherco 125 SE-R demands peak performance, a worn piston compromises power delivery and increases mechanical noise. This Wossner 53.94 mm piston kit restores efficiency and reliability with aerospace-grade construction and precision engineering...09106639- SKU:
- 09106639
- Availability:
- Ships Same Business Day
- Weight:
- 0.43 LBS
$132.00 -
Wossner Piston Kit 53.95 mm Sherco 125 SE-R 2018-2025 8303DC
WOSSNER
$132.00The stock piston in your 2018-2025 Sherco 125 SE-R experiences wear and friction that directly impact power delivery and engine longevity. This Wossner piston kit replaces that wear with precision-engineered components that restore—and exceed—OEM...09106640- SKU:
- 09106640
- Availability:
- Ships Same Business Day
- Weight:
- 0.46 LBS
$132.00 -
Wossner Piston Kit 66.35mm Yamaha YZ250 1999-2025 8217DA
WOSSNER
$182.00The Wossner 8217DA piston kit delivers the compression ratio stability and durability your YZ250 demands, whether you're pushing hard at the track or rebuilding after a season of aggressive riding. Forged from aerospace-grade aluminum with a permanent...09106641- SKU:
- 09106641
- Availability:
- Ships Same Business Day
- Weight:
- 0.73 LBS
$182.00 -
Wossner Piston Kit 66.36mm Yamaha YZ250 1999-2020 8217DB
WOSSNER
$182.00If you're running a YZ250 that sees serious track time, piston wear is inevitable—and it directly impacts combustion efficiency, throttle response, and engine longevity. This Wossner kit delivers OEM-quality engineering with measurable gains in...09106642- SKU:
- 09106642
- Availability:
- Ships Same Business Day
- Weight:
- 0.68 LBS
$182.00 -
Wossner Piston Kit 89.42mm Honda CR500R 1985-2001 8229D050
WOSSNER
$192.00Stock pistons limit your Honda CR500R's potential—they can't withstand the demands of aggressive riding or consistent high-RPM operation. The Wossner 89.42mm Piston Kit delivers the strength and precision you need to push your engine harder while...09106643- SKU:
- 09106643
- Availability:
- Ships Same Business Day
- Weight:
- 1.18 LBS
$192.00 -
Wossner Piston Kit 89.92mm Honda CR500R 1985-2001 8229D100
WOSSNER
$192.00If you're running a Honda CR500R, your piston kit directly determines how much power you can reliably extract from your engine—and whether that power translates to consistent performance across the RPM range. The Wossner 89.92mm Piston Kit is engineered...09106644- SKU:
- 09106644
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
$192.00Qty in Cart: 0Quantity:Price:$192.00Subtotal: -
Wossner Piston Kit 88.92mm Honda CR500R 1984-2001 8229DA
WOSSNER
$192.00If you're running a Honda CR500R and want reliable power delivery without sacrificing durability, a quality piston kit is non-negotiable. This Wossner unit maintains consistent compression and reduces mechanical noise while keeping weight down—critical...09106645- SKU:
- 09106645
- Availability:
- Ships Same Business Day
- Weight:
- 1.17 LBS
$192.00 -
Wossner Piston Kit 53.96mm Yamaha YZ125 2022-2025 8321DB
WOSSNER
$132.00A worn or damaged piston directly compromises combustion efficiency, throttle response, and engine longevity—especially critical in a high-revving two-stroke like the YZ125. The Wossner 8321DB delivers OEM-grade reliability with measurable reductions in...09106610- SKU:
- 09106610
- Availability:
- Ships Same Business Day
- Weight:
- 0.41 LBS
$132.00 -
Wossner Piston Kit 53.97mm Yamaha YZ125 2022-2024 8321DC
WOSSNER
$132.00If you're running a YZ125 at the limit, piston wear becomes your enemy—compromising combustion efficiency, increasing blow-by, and shortening engine life. This Wossner kit replaces worn internals with aerospace-grade forgings and precision coatings,...09106611- SKU:
- 09106611
- Availability:
- Ships Same Business Day
- Weight:
- 0.42 LBS
$132.00 -
On Sale
PROX Piston Kit - 78.97 mm - Honda CRF250R/CRF250RX 01.1350.A
PROX
MSRP: $188.95Now: $158.00Was: $188.95A worn or damaged piston compromises engine compression, throttle response, and overall reliability—especially critical in a high-revving 250cc four-stroke. The PROX Piston Kit delivers OEM-equivalent performance with precision CNC machining and...09106779- SKU:
- 09106779
- Availability:
- Ships Same Business Day
- Weight:
- 0.53 LBS
MSRP: $188.95Now: $158.00Was: $188.95 -
On Sale
PROX Piston Kit - 53.95 mm - Yamaha YZ125/YZ125X 01.2232.A
PROX
MSRP: $121.95Now: $90.00Was: $121.95A worn or damaged piston directly compromises your YZ125/YZ125X's power delivery, compression, and engine reliability. The PROX 53.95 mm Piston Kit restores your engine to OEM performance specifications with precision-manufactured components engineered...09106780- SKU:
- 09106780
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
MSRP: $121.95Now: $90.00Was: $121.95 -
On Sale
PROX Piston Kit - 96.95 mm - Yamaha WR450F/YZ450F/YZ450FX 01.2448.A
PROX
MSRP: $210.95Now: $167.00Was: $210.95When your Yamaha WR450F or YZ450F demands more from its engine, a quality piston kit is non-negotiable. This PROX kit delivers precision-machined components engineered to exact OEM specifications, restoring lost compression and power while maximizing...09106781- SKU:
- 09106781
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
MSRP: $210.95Now: $167.00Was: $210.95Qty in Cart: 0Quantity:Price:MSRP: $210.95Now: $167.00Was: $210.95Subtotal: -
On Sale
PROX Piston Kit - 96.95 mm - Yamaha WR450F/YZ450F/YZ450FX 01.2450.A
PROX
MSRP: $221.95Now: $183.00Was: $221.95A piston kit is one of the most critical components in your engine's combustion chamber—it directly impacts power delivery, reliability, and longevity. The PROX 96.95 mm kit for your WR450F/YZ450F/YZ450FX delivers precision-engineered components machined...09106782- SKU:
- 09106782
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
MSRP: $221.95Now: $183.00Was: $221.95 -
On Sale
PROX Piston Kit - 96.95 mm - Yamaha WR450F/YZ450F/YZ450FX 01.2453.A
PROX
MSRP: $221.95Now: $183.00Was: $221.95A worn or damaged piston directly impacts your WR450F or YZ450F's compression ratio, throttle response, and overall reliability—especially under high-RPM racing conditions. This PROX piston kit restores OEM specifications with precision-machined...09106783- SKU:
- 09106783
- Availability:
- Ships Same Business Day
- Weight:
- 0.93 LBS
MSRP: $221.95Now: $183.00Was: $221.95 -
On Sale
PROX Piston Kit - 77.96 mm - Kawasaki KX250/KX250X 01.4353.A
PROX
MSRP: $188.95Now: $158.00Was: $188.95The piston is the heart of your engine's combustion cycle—wear, scoring, or improper tolerances kill power and reliability. This PROX kit delivers OEM-equivalent precision for the Kawasaki KX250/KX250X, ensuring proper ring sealing, minimal blowby, and...09106787- SKU:
- 09106787
- Availability:
- Ships Same Business Day
- Weight:
- 0.50 LBS
MSRP: $188.95Now: $158.00Was: $188.95
