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
-
WSM Piston Kit - GP1200R - Standard 010-829PK
WSM
$98.28When you're running a GP1200R at the limit, stock pistons become a reliability liability. The WSM Piston Kit delivers OEM-equivalent quality with engineered improvements—specifically the MOS2 coating that actively dissipates heat and reduces friction,...010829BP- SKU:
- 010829BP
- Availability:
- Ships Same Business Day
- Weight:
- 1.32 LBS
- BORE SIZE METRIC:
- 80.00 MM
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
- MODEL:
- PLATINUM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
$98.28 -
WSM Piston Kit - Polaris 750 - Standard 010-830K
WSM
$89.33When you're pushing a Polaris 750 to its limits, factory pistons can't keep pace with the heat and stress your engine generates. The WSM Piston Kit delivers OEM-equivalent quality with critical upgrades—MOS2-coated skirts that actively dissipate heat...010830- SKU:
- 010830
- Availability:
- Ships Same Business Day
- Weight:
- 0.55 LBS
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 69.75 MM
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
- RIDING STYLE:
- WATERCRAFT
- PISTON MATERIAL:
- ALUMINUM
$89.33 -
WSM Piston Kit - Polaris 750 - +.5 mm 010-830-05K
WSM
$89.33If you're pushing your Polaris 750 to the limit, factory pistons won't cut it—especially at higher boost levels or sustained RPMs. The WSM +.5mm piston kit delivers OEM-matched quality with critical upgrades: a MOS2-coated skirt that actively dissipates...01083005- SKU:
- 01083005
- Availability:
- Ships Same Business Day
- Weight:
- 0.65 LBS
- RIDING STYLE:
- WATERCRAFT
- BORE SIZE METRIC:
- 69.75 MM
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE:
- +0,50 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- UNITS:
- KIT
$89.33Qty in Cart: 0Quantity:Price:$89.33Subtotal: -
WSM Piston Kit - Polaris - +.5 mm 010-832-05K
WSM
$98.28High-output piston kits demand precision engineering and thermal management that stock components simply can't deliver. The WSM +.5 mm Piston Kit brings OEM-matching quality with enhanced durability features specifically designed to handle the demands of...01083205- SKU:
- 01083205
- Availability:
- Ships Same Business Day
- Weight:
- 0.78 LBS
- RIDING STYLE:
- WATERCRAFT
- BORE SIZE METRIC:
- 81.00 MM
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE:
- +0,50 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- UNITS:
- KIT
$98.28 -
WSM Piston Kit - Yamaha - Standard 010-826K
WSM
$89.33If you're rebuilding a Yamaha engine or replacing worn pistons, the WSM Piston Kit delivers OEM-equivalent quality with performance-focused engineering. The MOS2-coated skirts reduce friction and heat while actively drawing thermal energy away from the...010826- SKU:
- 010826
- Availability:
- Ships Same Business Day
- Weight:
- 1.19 LBS
- PISTON MATERIAL:
- ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 84.00 MM
- MODEL:
- ORIGINAL
$89.33 -
WSM Piston Kit - Yamaha - +.25 mm 010-826-04K
WSM
$89.33Stock pistons can't handle the demands of high-performance builds—thermal stress, detonation, and friction all contribute to premature failure and power loss. The WSM Piston Kit delivers OEM-grade construction with critical performance upgrades,...01082604- SKU:
- 01082604
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- BORE - OVERSIZE:
- +0,25 MM
- RIDING STYLE:
- WATERCRAFT
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
- BORE - OVERSIZE METRIC:
- +0.25 MM
- BORE SIZE METRIC:
- 84.00 MM
- PRODUCT NAME:
- PISTON KIT
$89.33Qty in Cart: 0Quantity:Price:$89.33Subtotal: -
WSM Piston Kit - Yamaha - +.5 mm 010-826-05K
WSM
$89.33A properly matched piston kit is critical for reliable high-RPM performance and cylinder longevity. WSM's +.5mm oversized pistons deliver OEM-quality construction with performance-focused engineering—the MOS2 coating on the skirts actively reduces...01082605- SKU:
- 01082605
- Availability:
- Ships Same Business Day
- Weight:
- 1.19 LBS
- BORE SIZE METRIC:
- 84.00 MM
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- +0,50 MM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- UNITS:
- KIT
- PRODUCT NAME:
- PISTON KIT
$89.33Qty in Cart: 0Quantity:Price:$89.33Subtotal: -
WSM Piston Kit - K1200 - Standard 010-841PK
WSM
$98.28Stock pistons wear down, lose compression, and rob your engine of power and efficiency. The WSM Piston Kit K1200 restores your engine to peak performance with OEM-matching quality and engineering refinements that factory units simply don't offer. The...010841P- SKU:
- 010841P
- Availability:
- Ships Same Business Day
- Weight:
- 1.32 LBS
- PRODUCT NAME:
- PISTON KIT
- MODEL:
- PLATINUM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- BORE SIZE METRIC:
- 80.00 MM
$98.28 -
WSM Piston Kit - Kawasaki - Standard 010-812K
WSM
$73.24If you're rebuilding a Kawasaki engine or replacing worn pistons, you need a kit engineered to handle the demands of high-RPM operation without sacrificing longevity. WSM's piston kit delivers OEM-equivalent quality with performance-enhancing...010812X- SKU:
- 010812X
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
- BORE SIZE METRIC:
- 75.00 MM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- MODEL:
- ORIGINAL
$73.24 -
WSM Piston Kit - Sea-Doo - Standard 010-815K
WSM
$73.24A quality piston kit is the foundation of reliable, high-output engine performance—especially in demanding two-stroke applications where heat and friction directly impact power delivery and component longevity. The WSM Piston Kit for Sea-Doo uses...010815- SKU:
- 010815
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- PISTON MATERIAL:
- ALUMINUM
- BORE - OVERSIZE:
- STANDARD
- BORE SIZE METRIC:
- 76.00 MM
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE METRIC:
- STANDARD
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
$73.24Qty in Cart: 0Quantity:Price:$73.24Subtotal: -
WSM Piston Kit - Sea-Doo - +1 mm 010-815-07K
WSM
$73.24When you're pushing your Sea-Doo to the limit, your stock pistons become the weak link in the chain. The WSM Piston Kit delivers OEM-matching quality with engineered upgrades—MOS2 coating on the skirts reduces friction and heat while actually drawing...01081507- SKU:
- 01081507
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- BORE SIZE METRIC:
- 76.00 MM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE:
- +1,00 MM
- UNITS:
- KIT
- BORE - OVERSIZE METRIC:
- +1.00 MM
- PISTON MATERIAL:
- ALUMINUM
- RIDING STYLE:
- WATERCRAFT
- MODEL:
- ORIGINAL
$73.24Qty in Cart: 0Quantity:Price:$73.24Subtotal: -
MOOSE RACING Piston Kit - 43.46 mm MSE24352B
MOOSE RACING
$127.95A quality piston kit is fundamental to engine reliability and longevity, especially under high-load conditions where thermal stress and wear accelerate component failure. The MOOSE RACING Piston Kit delivers durability through precision engineering and...09105957- SKU:
- 09105957
- Availability:
- Ships Same Business Day
- Weight:
- 0.26 LBS
- PISTON DIAMETER METRIC:
- 43.46 MM
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PISTON MATERIAL:
- ALUMINUM ALLOY
$127.95 -
MOOSE RACING Piston Kit MSE24384B
MOOSE RACING
$191.95Engine longevity depends on reliable piston performance, especially in high-demand applications where thermal stress and friction accelerate wear. The MOOSE RACING Piston Kit MSE24384B delivers gravity-cast construction engineered to withstand extreme...09106021- SKU:
- 09106021
- Availability:
- Ships Same Business Day
- Weight:
- 0.81 LBS
- UNITS:
- KIT
- PISTON DIAMETER METRIC:
- 66.36 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- OFF-ROAD
$191.95 -
MOOSE RACING Piston Kit MSE24385B
MOOSE RACING
$154.95Factory pistons wear out—especially under high RPM or forced induction conditions. The MOOSE RACING Piston Kit MSE24385B combines gravity-cast aluminum with 18% silicon content to dramatically reduce thermal distortion and extend service life, while...09106023- SKU:
- 09106023
- Availability:
- Ships Same Business Day
- Weight:
- 0.61 LBS
- PISTON DIAMETER METRIC:
- 71.96 MM
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- PISTON MATERIAL:
- ALUMINUM ALLOY
$154.95Qty in Cart: 0Quantity:Price:$154.95Subtotal: -
MOOSE RACING Piston Kit - 66.36 mm MSE22521B
MOOSE RACING
$203.65A piston kit engineered for durability and extended service life, the MOOSE RACING MSE22521B combines gravity-cast aluminum with 18% silicon content to resist wear and thermal distortion under demanding conditions. Whether you're rebuilding after...09102679- SKU:
- 09102679
- Availability:
- Ships Same Business Day
- Weight:
- 0.74 LBS
- PISTON MATERIAL:
- ALUMINUM ALLOY
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- STYLE:
- CAST REPLICA
- CYLINDER DIAMETER METRIC:
- 66.40 MM
- DISPLACEMENT:
- 250 CC
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- PISTON KIT
- COMPRESSION RATIO IMPERIAL:
- STOCK
- PISTON DIAMETER METRIC:
- 66.36 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$203.65 -
MOOSE RACING Piston Kit - 53.94 mm MSE22189B
MOOSE RACING
$146.95If you're rebuilding an engine or recovering from ring blow-by, a quality piston kit is non-negotiable. MOOSE Racing's gravity-cast design with 18% silicon content resists wear and thermal distortion, giving you the reliability needed for consistent...09102669- SKU:
- 09102669
- Availability:
- Ships Same Business Day
- Weight:
- 0.37 LBS
- ENGINE TYPE:
- 2-STROKE
- STYLE:
- CAST REPLICA
- COMPRESSION RATIO IMPERIAL:
- STOCK
- PISTON DIAMETER METRIC:
- 53.94 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- OFF-ROAD
- SKIRT COATING:
- MOLYBDENUM DISULPHITE
- UNITS:
- KIT
- DISPLACEMENT:
- 125 CC
- CYLINDER DIAMETER METRIC:
- 54.00 MM
- PRODUCT NAME:
- PISTON KIT
$146.95 -
MOOSE RACING Piston Kit - 53.94 mm MSE22685C
MOOSE RACING
$99.95A piston kit is one of the most critical internal upgrades for extending engine life and maintaining peak performance under high-load conditions. The MOOSE Racing MSE22685C combines gravity-cast aluminum with 18% silicon content to deliver exceptional...09102689- SKU:
- 09102689
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
- PISTON DIAMETER METRIC:
- 53.94 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- PISTON KIT
- PISTON MATERIAL:
- ALUMINUM ALLOY
$99.95Qty in Cart: 0Quantity:Price:$99.95Subtotal: -
MOOSE RACING Piston Kit - 44.45 mm MSE22860B
MOOSE RACING
$113.35A piston kit is fundamental to engine longevity and reliability—especially under high-load conditions. The MOOSE RACING MSE22860B combines precision gravity-cast construction with wear-resistant coatings designed to minimize friction during break-in and...09102697- SKU:
- 09102697
- Availability:
- Ships Same Business Day
- Weight:
- 0.25 LBS
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON DIAMETER METRIC:
- 44.45 MM
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$113.35 -
JE PISTONS Piston Kit 291517
JE PISTONS
$309.99When you're pushing your engine to the absolute limit in competition or extreme performance applications, piston failure isn't an option. The JE PISTONS Piston Kit 291517 delivers the strength, precision, and weight optimization demanded by professional...09105905- SKU:
- 09105905
- Availability:
- Ships Same Business Day
- Weight:
- 0.65 LBS
- BORE SIZE METRIC:
- 76.80 MM
- COMPRESSION RATIO IMPERIAL:
- 14.2:1
- BORE - OVERSIZE METRIC:
- STANDARD
- PISTON HEAD SHAPE:
- DOMED
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- DISPLACEMENT:
- 249 CC
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- PRODUCT NAME:
- PISTON KIT
- TYPE:
- FORGED SIDE RELIEF DESIGN
- BORE - OVERSIZE:
- STANDARD
- STYLE:
- PRO SERIES
$309.99Qty in Cart: 0Quantity:Price:$309.99Subtotal: -
JE PISTONS Piston Kit 292330
JE PISTONS
$269.99When you're pushing your engine to the limit in professional competition, your pistons need to survive extreme pressures and temperatures without compromise. JE Pistons' 2618-T6 forged aluminum construction delivers the strength and reliability required...09105906- SKU:
- 09105906
- Availability:
- Ships Same Business Day
- Weight:
- 1.51 LBS
- BORE - OVERSIZE:
- +1,00 MM
- PRODUCT NAME:
- PISTON KIT
- COMPRESSION RATIO IMPERIAL:
- 9.0:1
- PISTON HEAD SHAPE:
- FLAT TOP
- PISTON MATERIAL:
- FORGED 2618 ALUMINUM
- STYLE:
- JE PISTON
- BORE - OVERSIZE METRIC:
- +1.00 MM
- TYPE:
- ROUND FORGED DESIGN
- UNITS:
- KIT
- BORE SIZE METRIC:
- 101.00 MM
- DISPLACEMENT:
- 650 CC
- RIDING STYLE:
- OFF-ROAD
$269.99
