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
-
Wossner Piston Kit 72.96mm Beta 300 RR 2022-2026 8324DB
WOSSNER
$192.00OEM pistons wear out, but a quality replacement kit restores lost compression and throttle response while preventing catastrophic engine failure. The Wossner 72.96mm piston kit for your Beta 300 RR delivers the precision engineering and durability you...09106630- SKU:
- 09106630
- Availability:
- Ships Same Business Day
- Weight:
- 0.87 LBS
$192.00 -
On Sale
PROX Piston Kit - 77.96 mm - Kawasaki KX250/KX250X 01.4351.A
PROX
MSRP: $188.95Now: $158.00Was: $188.95A worn or damaged piston directly compromises your KX250/KX250X's compression, throttle response, and overall reliability. The PROX 77.96 mm Piston Kit restores factory performance specifications with OEM-grade components, ensuring your engine runs at...09106786- SKU:
- 09106786
- Availability:
- Ships Same Business Day
- Weight:
- 0.40 LBS
MSRP: $188.95Now: $158.00Was: $188.95 -
On Sale
PROX Piston Kit - 71.94 mm - Beta 01.7398.A
PROX
MSRP: $221.95Now: $170.00Was: $221.95When your piston fails, engine performance tanks—and so does your race day. The PROX Piston Kit delivers OEM-equivalent reliability with CNC precision, ensuring consistent compression, proper ring seal, and the durability needed for sustained high-RPM...09106807- SKU:
- 09106807
- Availability:
- Ships Same Business Day
- Weight:
- 0.01 LBS
MSRP: $221.95Now: $170.00Was: $221.95Qty in Cart: 0Quantity:Price:MSRP: $221.95Now: $170.00Was: $221.95Subtotal: -
VERTEX Top End Piston Kit - 66.35 mm - Gas Gas | Husqvarna | KTM VTK23630B-3
VERTEX
$307.95When your top end starts showing signs of wear—whether it's lost compression, increased blow-by, or sluggish throttle response—a quality piston kit is essential to restore your bike's original performance and reliability. The VERTEX Top End Piston Kit...09106822- SKU:
- 09106822
- Availability:
- Ships Same Business Day
- Weight:
- 1.30 LBS
$307.95 -
WOSSNER Piston Kit - 53.95 mm - Yamaha 8321DA
WOSSNER
$132.00High-revving engines demand pistons engineered for precision and durability. WOSSNER's aerospace-grade forged construction delivers the strength needed for sustained performance while their permanent skirt coating minimizes friction and piston...09106837- SKU:
- 09106837
- Availability:
- Ships Same Business Day
- Weight:
- 0.45 LBS
$132.00Qty in Cart: 0Quantity:Price:$132.00Subtotal: -
Wossner Piston Kit 94.95 mm Husqvarna FC450 2023-2024 4097DA
WOSSNER
$214.00When your FC450 demands peak performance, a worn or stock piston becomes your limiting factor. The Wossner 94.95 mm Piston Kit delivers the precision engineering and durability required to sustain high RPMs and aggressive riding conditions while reducing...09106845- SKU:
- 09106845
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
$214.00 -
MOOSE RACING Piston Kit MX1026
MOOSE RACING
$0.00If you're pushing your engine to the limit, a stock piston won't cut it—especially under sustained high RPM or forced induction. The MOOSE RACING Piston Kit MX1026 is engineered to handle extreme conditions with forgings designed to reduce stress...9106488- SKU:
- 9106488
- Availability:
- Ships Same Business Day
- Weight:
- 18.40 LBS
$0.00Qty in Cart: 0Quantity:Price:$0.00Subtotal: -
MOOSE RACING Piston Kit MPX2082
MOOSE RACING
$0.00When you're pushing your engine to its limits, stock pistons simply won't cut it. The MOOSE RACING Piston Kit MPX2082 delivers race-proven durability and reduced friction through precision X-style and fully boxed forgings, engineered to handle extreme...9106518- SKU:
- 9106518
- Availability:
- Ships Same Business Day
- Weight:
- 12.80 LBS
$0.00Qty in Cart: 0Quantity:Price:$0.00Subtotal: -
MOOSE RACING Piston Kit MPX2083A-P
MOOSE RACING
$0.00If you're pushing your engine to its limits, stock pistons won't cut it. The MOOSE RACING Piston Kit MPX2083A-P is engineered with X-style and fully-boxed race forgings that deliver the strength, durability, and power reduction you need for sustained...9106519- SKU:
- 9106519
- Availability:
- Ships Same Business Day
- Weight:
- 12.80 LBS
$0.00Qty in Cart: 0Quantity:Price:$0.00Subtotal: -
MOOSE RACING Piston Kit MPX2059
MOOSE RACING
$0.00Whether you're chasing lap records or rebuilding after a catastrophic failure, piston reliability is non-negotiable. The MOOSE RACING Piston Kit MPX2059 combines race-proven forging technology with precision engineering to handle extreme combustion...9106487- SKU:
- 9106487
- Availability:
- Ships Same Business Day
- Weight:
- 17.60 LBS
$0.00Qty in Cart: 0Quantity:Price:$0.00Subtotal: -
MOOSE RACING Piston Kit MP3031C
MOOSE RACING
$0.00High-RPM racing demands pistons engineered to handle extreme cylinder pressures without sacrificing reliability. The MOOSE RACING Piston Kit MP3031C delivers race-proven forging technology with internal bracing and DLC pin coatings that reduce friction...9106484- SKU:
- 9106484
- Availability:
- Ships Same Business Day
- Weight:
- 12.80 LBS
$0.00Qty in Cart: 0Quantity:Price:$0.00Subtotal: -
MOOSE RACING Piston Kit MP3035
MOOSE RACING
$125.95Whether you're pushing peak boost or maximizing naturally aspirated output, piston durability and ring seal are non-negotiable. The MOOSE RACING Piston Kit MP3035 delivers race-proven construction designed to handle extreme cylinder pressures while...09106481- SKU:
- 09106481
- Availability:
- Ships Same Business Day
- Weight:
- 19.20 LBS
$125.95Qty in Cart: 0Quantity:Price:$125.95Subtotal: -
MOOSE RACING Piston Kit - 71.95 mm MSE23375B
MOOSE RACING
$141.95Engine wear accelerates under sustained performance demands, and OEM pistons often fail to meet the durability requirements of serious racers and high-mileage builds. The MOOSE RACING Piston Kit MSE23375B delivers gravity-cast construction with enhanced...09102714- SKU:
- 09102714
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- UNITS:
- KIT
- ENGINE TYPE:
- 2-STROKE
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- OFF-ROAD
- PISTON DIAMETER METRIC:
- 71.95 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
$141.95Qty in Cart: 0Quantity:Price:$141.95Subtotal: -
WSM Piston Kit - Kawasaki 900 - Standard 010-840K
WSM
$76.57A piston kit is one of the most critical internal components you'll upgrade in a high-performance build—it directly impacts compression ratio, heat dissipation, and ring sealing consistency. The WSM 010-840K delivers OEM-equivalent quality with...010840- SKU:
- 010840
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- BORE SIZE METRIC:
- 73.00 MM
- PRODUCT NAME:
- PISTON KIT
- PISTON MATERIAL:
- ALUMINUM
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- MODEL:
- ORIGINAL
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
$76.57Qty in Cart: 0Quantity:Price:$76.57Subtotal: -
WSM Piston Kit - Polaris - Standard 010-834K
WSM
$85.08Piston failure under load is one of the costliest failures in high-performance engines. The WSM Piston Kit delivers OEM-quality construction with measurable improvements in heat management and ring groove durability, directly translating to longer engine...010834- SKU:
- 010834
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- BORE SIZE METRIC:
- 71.30 MM
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
$85.08Qty in Cart: 0Quantity:Price:$85.08Subtotal: -
WSM Piston Kit - Sea-Doo - +.50 mm 010-816-05K
WSM
$76.57Sea-Doo pistons experience extreme heat and pressure during extended operation, making OEM-quality replacements essential for maintaining peak performance and engine longevity. The WSM Piston Kit delivers precision-engineered internals with advanced...01081605- SKU:
- 01081605
- Availability:
- Ships Same Business Day
- Weight:
- 1.06 LBS
- BORE - OVERSIZE METRIC:
- +0.50 MM
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- +0,50 MM
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
- BORE SIZE METRIC:
- 78.00 MM
$76.57Qty in Cart: 0Quantity:Price:$76.57Subtotal: -
WSM Piston Kit - Kawasaki - Standard 010-821K
WSM
$85.08When you're pushing your Kawasaki to the limit, stock pistons become your weak point. The WSM Piston Kit delivers OEM-equivalent quality with engineering upgrades that reduce friction, manage heat more effectively, and extend piston life under sustained...010821- SKU:
- 010821
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- PISTON MATERIAL:
- ALUMINUM
- BORE SIZE METRIC:
- 80.00 MM
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- WATERCRAFT
- UNITS:
- KIT
- BORE - OVERSIZE:
- STANDARD
- BORE - OVERSIZE METRIC:
- STANDARD
- MODEL:
- ORIGINAL
$85.08Qty in Cart: 0Quantity:Price:$85.08Subtotal: -
WSM Piston Kit - Polaris - Standard 010-832K
WSM
$93.60If you're running Polaris sleds hard, your stock pistons are likely your weakest link—heat and friction rob horsepower and shorten engine life. The WSM Piston Kit replaces worn or damaged pistons with OEM-equivalent or better construction, while the...010832- SKU:
- 010832
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- BORE - OVERSIZE METRIC:
- STANDARD
- UNITS:
- KIT
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- STANDARD
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- BORE SIZE METRIC:
- 81.00 MM
- PRODUCT NAME:
- PISTON KIT
$93.60Qty in Cart: 0Quantity:Price:$93.60Subtotal: -
WSM Piston Kit - Sea-Doo - +.5 mm 010-815-05K
WSM
$73.24Stock pistons are a compromise between cost and performance—but your Sea-Doo engine deserves better. WSM Piston Kits deliver OEM-equivalent quality with measurable gains in durability and power through advanced materials and precision engineering...01081505- SKU:
- 01081505
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- BORE - OVERSIZE METRIC:
- +0.50 MM
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- WATERCRAFT
- BORE - OVERSIZE:
- +0,50 MM
- MODEL:
- ORIGINAL
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
- BORE SIZE METRIC:
- 76.00 MM
$73.24 -
Wossner Piston Kit KTM 250 2005-2025 8169DC
WOSSNER
$152.00When your 2-stroke KTM 250 is pushing hard on the track or trail, your piston kit needs to deliver consistent power while managing extreme temperatures and loads. The Wossner 8169DC is engineered to replace worn or damaged pistons with a complete...09104863- SKU:
- 09104863
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- ENGINE TYPE:
- 2-STROKE
- PISTON SIZE METRIC:
- 66.36 MM
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- BORE - OVERSIZE METRIC:
- +0.02 MM
- BORE SIZE METRIC:
- 66.42 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON MATERIAL:
- FORGED
- BORE - OVERSIZE:
- +0,02 MM
- DISPLACEMENT:
- 249 CC
- MODEL:
- STANDARD SERIES
- PRODUCT NAME:
- PISTON KIT
- TYPE:
- DUAL RING
$152.00
