ATV/UTV Piston and Ring Kits
ATV/UTV Piston & Ring Kits at JJ Motorsports
Rebuild your ATV/UTV engine with premium forged piston and ring kits from JJ Motorsports, featuring high-compression and big-bore options for massive power gains on Yamaha YFZ450, Honda TRX450R, Suzuki LTZ400, and more. These race-proven kits deliver superior durability and performance in off-road, trail, and dune conditions.
Shop Millennium, JE Pistons, and Wossner piston kits for championship-level quality. Explore related categories such as ATV/UTV engine for cylinders and gaskets, or ATV/UTV for cams and exhaust to complete your top-end rebuild and dominate the track or trail.
Top ATV/UTV Piston & Ring Kits
- Millennium Piston Kit K8897D500-2 – +5.00mm big-bore piston kit; forged for Yamaha YFZ450/R with rings, pin, and clips.
- JE Pistons Piston Kit 261546 – High-compression forged piston; includes rings and wrist pin for Honda TRX450R.
- Wossner Piston Kit 8094D050 – +0.50mm oversize piston kit; lightweight forged with moly coating for Suzuki LTZ400.
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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WSM Piston Kit - Honda 350 - +.25 mm 50-226-04K
WSM
$113.93Stock pistons are a compromise between cost and performance—they generate excessive heat, suffer friction losses, and wear faster under racing conditions. The WSM Piston Kit replaces these...09103479- SKU:
- 09103479
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- BORE - OVERSIZE METRIC:
- +0.25 MM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE:
- +0,25 MM
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
- BORE SIZE METRIC:
- 78.75 MM
- MODEL:
- ORIGINAL
- RIDING STYLE:
- ATV
$113.93Qty in Cart: 0Quantity:Price:$113.93Subtotal: -
WSM Piston Kit - Honda 350 - +.50 mm 50-226-05K
WSM
$113.93When you're pushing your Honda 350 to the limit, OEM pistons become a bottleneck. This WSM Piston Kit delivers the durability and thermal management you need to extract more power while maintaining...09103480- SKU:
- 09103480
- Availability:
- Ships Same Business Day
- Weight:
- 0.85 LBS
- PISTON MATERIAL:
- ALUMINUM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE - OVERSIZE:
- +0,50 MM
- MODEL:
- ORIGINAL
- RIDING STYLE:
- ATV
- UNITS:
- KIT
- BORE SIZE METRIC:
- 79.00 MM
- PRODUCT NAME:
- PISTON KIT
$113.93Qty in Cart: 0Quantity:Price:$113.93Subtotal: -
WSM Piston Kit - Honda 350 - +.75 mm 50-226-06K
WSM
$113.93If you're running a Honda 350 and want measurable gains in power output and piston longevity, the WSM +.75 mm Piston Kit delivers the thermal management and structural integrity that separates...09103481- SKU:
- 09103481
- Availability:
- Ships Same Business Day
- Weight:
- 0.65 LBS
- BORE SIZE METRIC:
- 79.25 MM
- PISTON MATERIAL:
- ALUMINUM
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- ATV
- UNITS:
- KIT
- BORE - OVERSIZE:
- +0,75 MM
- BORE - OVERSIZE METRIC:
- +0.75 MM
$113.93 -
WSM Piston Kit - Honda 350 - +1 mm 50-226-07K
WSM
$113.93If you're running a high-revving Honda 350 and want measurable gains in power and reliability, upgrading to forged pistons is one of the most direct paths to both. The WSM Piston Kit delivers...09103482- SKU:
- 09103482
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- BORE - OVERSIZE METRIC:
- +1.00 MM
- MODEL:
- ORIGINAL
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- ATV
- BORE - OVERSIZE:
- +1,00 MM
- BORE SIZE METRIC:
- 79.50 MM
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
$113.93Qty in Cart: 0Quantity:Price:$113.93Subtotal: -
WSM Piston Kit - Honda 400 - +.25 mm 50-228-04K
WSM
$128.36A piston kit is one of the most critical upgrades for extracting reliable power from your Honda 400 engine. The WSM +.25 mm oversized pistons deliver improved ring groove strength and reduced...09103484- SKU:
- 09103484
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- MODEL:
- ORIGINAL
- RIDING STYLE:
- ATV
- BORE - OVERSIZE:
- +0,25 MM
- BORE SIZE METRIC:
- 85.25 MM
- PRODUCT NAME:
- PISTON KIT
- BORE - OVERSIZE METRIC:
- +0.25 MM
- PISTON MATERIAL:
- ALUMINUM
- UNITS:
- KIT
$128.36Qty in Cart: 0Quantity:Price:$128.36Subtotal: -
WSM Piston Kit - Honda 400 - +.50 mm 50-228-05K
WSM
$128.36A piston kit is the heart of your engine's combustion chamber—factory pistons wear out, develop carbon buildup, and lose efficiency over time. This WSM piston kit delivers OEM-quality construction...09103485- SKU:
- 09103485
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- MODEL:
- ORIGINAL
- RIDING STYLE:
- ATV
- BORE SIZE METRIC:
- 85.50 MM
- PISTON MATERIAL:
- ALUMINUM
- BORE - OVERSIZE METRIC:
- +0.50 MM
- BORE - OVERSIZE:
- +0,50 MM
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- KIT
$128.36Qty in Cart: 0Quantity:Price:$128.36Subtotal: -
PROX Piston Kit 01.1496.A
PROX
$210.95Whether you're rebuilding after high-mileage wear or restoring a seized engine, piston failure isn't an option. The PROX Piston Kit 01.1496.A delivers OEM-equivalent reliability with the precision...09101191- SKU:
- 09101191
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- PISTON DIAMETER METRIC:
- 95.96 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
- BORE SIZE METRIC:
- 95.96 MM
- ENGINE TYPE:
- 4-STROKE
- RIDING STYLE:
- ATV
- PISTON SIZE METRIC:
- STANDARD SIZE A
- PRODUCT NAME:
- PISTON KIT
$210.95 -
PROX Piston Kit 01.1496.B
PROX
$195.95When your engine demands reliability under extreme conditions, OEM-equivalent pistons are non-negotiable. The PROX Piston Kit 01.1496.B delivers factory-specification performance with Japanese...09101192- SKU:
- 09101192
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- PISTON DIAMETER METRIC:
- 95.97 MM
- PISTON SIZE METRIC:
- STANDARD SIZE B
- BORE SIZE METRIC:
- 95.97 MM
- PRODUCT NAME:
- PISTON KIT
$195.95Qty in Cart: 0Quantity:Price:$195.95Subtotal: -
PROX Piston Kit 01.1496.C
PROX
$195.95When your engine demands reliability that matches factory specifications, the PROX Piston Kit 01.1496.C delivers the precision engineering required for consistent performance and longevity. This...09101193- SKU:
- 09101193
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- PISTON SIZE METRIC:
- STANDARD SIZE C
- BORE SIZE METRIC:
- 95.98 MM
- PISTON DIAMETER METRIC:
- 95.98 MM
- PRODUCT NAME:
- PISTON KIT
$195.95Qty in Cart: 0Quantity:Price:$195.95Subtotal: -
PROX Piston Kit 01.2436.B
PROX
$210.95A piston kit is the beating heart of your engine—when tolerances drift or ring blow-by creeps in, your power delivery suffers and fuel economy tanks. The PROX Piston Kit 01.2436.B delivers...09101197- SKU:
- 09101197
- Availability:
- Ships Same Business Day
- Weight:
- 0.90 LBS
- BORE SIZE METRIC:
- 94.96 MM
- PISTON SIZE METRIC:
- STANDARD SIZE B
- ENGINE TYPE:
- 4-STROKE
- PISTON DIAMETER METRIC:
- 94.96 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- ATV
- UNITS:
- EACH
$210.95 -
PROX Piston Kit 01.2487.000
PROX
$121.95Worn or damaged pistons compromise combustion efficiency, power delivery, and engine longevity. The PROX Piston Kit 01.2487.000 restores your engine to OEM performance specifications with...09101198- SKU:
- 09101198
- Availability:
- Ships Same Business Day
- Weight:
- 0.98 LBS
- BORE SIZE METRIC:
- 83.00 MM
- PISTON DIAMETER METRIC:
- 83.00 MM
- PRODUCT NAME:
- PISTON KIT
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON SIZE METRIC:
- STANDARD
- RIDING STYLE:
- ATV
- UNITS:
- EACH
$121.95 -
PROX Piston Kit 01.2487.050
PROX
$121.95A piston kit is the foundation of reliable engine performance, and worn or damaged pistons directly compromise compression, power delivery, and engine longevity. The PROX Piston Kit 01.2487.050...09101199- SKU:
- 09101199
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- BORE SIZE METRIC:
- 83.50 MM
- PISTON DIAMETER METRIC:
- 83.50 MM
- PRODUCT NAME:
- PISTON KIT
- ENGINE TYPE:
- 4-STROKE
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON SIZE METRIC:
- +0.50 MM
$121.95 -
PROX Piston Kit 01.2706.A
PROX
$149.95A piston kit is one of the most critical internal engine components you'll rebuild or replace, and choosing the right one directly impacts engine reliability, efficiency, and longevity. The PROX...09101201- SKU:
- 09101201
- Availability:
- Ships Same Business Day
- Weight:
- 1.19 LBS
- PISTON SIZE METRIC:
- STANDARD SIZE A
- PRODUCT NAME:
- PISTON KIT
- BORE SIZE METRIC:
- 101.94 MM
- RIDING STYLE:
- UTV
- ENGINE TYPE:
- 4-STROKE
- RIDING STYLE:
- ATV
- PISTON DIAMETER METRIC:
- 101.94 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
$149.95 -
PROX Piston Kit 01.2706.B
PROX
$149.95A piston kit is the foundation of engine reliability and performance—worn or damaged pistons directly compromise compression, power delivery, and engine longevity. The PROX Piston Kit 01.2706.B...09101202- SKU:
- 09101202
- Availability:
- Ships Same Business Day
- Weight:
- 1.20 LBS
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- UTV
- PISTON DIAMETER METRIC:
- 101.95 MM
- PISTON SIZE METRIC:
- STANDARD SIZE B
- BORE SIZE METRIC:
- 101.95 MM
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- ATV
- UNITS:
- EACH
$149.95 -
PROX Piston Kit 01.2707.A
PROX
$149.95Piston failure doesn't just sideline your engine—it can destroy your entire build. The PROX Piston Kit 01.2707.A delivers OEM-spec reliability with precision manufacturing that keeps your combustion...09101204- SKU:
- 09101204
- Availability:
- Ships Same Business Day
- Weight:
- 1.24 LBS
- PISTON DIAMETER METRIC:
- 101.94 MM
- BORE SIZE METRIC:
- 101.94 MM
- RIDING STYLE:
- UTV
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- PISTON SIZE METRIC:
- STANDARD SIZE A
- PRODUCT NAME:
- HIGH COMPRESSION PISTON KIT
$149.95Qty in Cart: 0Quantity:Price:$149.95Subtotal: -
PROX Piston Kit 01.3420.A
PROX
$205.95A worn or damaged piston directly compromises engine efficiency, compression, and reliability—making a quality replacement essential for maintaining peak performance. The PROX Piston Kit 01.3420.A...09101206- SKU:
- 09101206
- Availability:
- Ships Same Business Day
- Weight:
- 0.86 LBS
- BORE SIZE METRIC:
- 89.96 MM
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PISTON SIZE METRIC:
- STANDARD
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- EACH
- PISTON DIAMETER METRIC:
- 89.96 MM
- RIDING STYLE:
- ATV
- RIDING STYLE:
- OFF-ROAD
$205.95 -
PROX Piston Kit 01.3420.C
PROX
$205.95Pistons are the hardworking heart of any engine, converting combustion energy into power. When OEM pistons wear or fail, you need a direct replacement that matches factory specifications without...09101208- SKU:
- 09101208
- Availability:
- Ships Same Business Day
- Weight:
- 0.86 LBS
- PISTON DIAMETER METRIC:
- 89.98 MM
- PRODUCT NAME:
- PISTON KIT
- BORE SIZE METRIC:
- 89.98 MM
- PISTON SIZE METRIC:
- STANDARD SIZE C
- RIDING STYLE:
- OFF-ROAD
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- ATV
- UNITS:
- EACH
$205.95 -
PROX Piston Kit 01.2435.A
PROX
$210.95A piston kit is one of the most critical components in your engine's combustion cycle, and worn or damaged pistons directly compromise compression, power output, and reliability. The PROX Piston Kit...09100603- SKU:
- 09100603
- Availability:
- Ships Same Business Day
- Weight:
- 0.92 LBS
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- BORE SIZE METRIC:
- 94.95 MM
- PISTON DIAMETER METRIC:
- 94.95 MM
- PISTON SIZE METRIC:
- STANDARD
- PRODUCT NAME:
- PISTON KIT
$210.95 -
PROX Piston Kit 01.2435.C
PROX
$195.95When your engine's pistons wear beyond acceptable tolerances, power delivery suffers, compression drops, and fuel efficiency tanks. The PROX Piston Kit 01.2435.C restores your engine to factory...09100605- SKU:
- 09100605
- Availability:
- Ships Same Business Day
- Weight:
- 0.92 LBS
- PISTON SIZE METRIC:
- +0.50 MM
- BORE SIZE METRIC:
- 94.97 MM
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- PISTON DIAMETER METRIC:
- 94.97 MM
- PRODUCT NAME:
- PISTON KIT
$195.95Qty in Cart: 0Quantity:Price:$195.95Subtotal: -
PROX Piston Kit 01.2020.250
PROX
$99.95OEM-specification pistons are critical to engine reliability and performance consistency—factory tolerances and materials directly impact combustion efficiency, ring seal integrity, and long-term...09100891- SKU:
- 09100891
- Availability:
- Ships Same Business Day
- Weight:
- 0.71 LBS
- BORE SIZE METRIC:
- 66.50 MM
- ENGINE TYPE:
- 2-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- STREET
- PISTON SIZE METRIC:
- +2.50 MM
- PISTON DIAMETER METRIC:
- 66.50 MM
$99.95
