ATV/UTV Engine
ATV/UTV Engine Parts at JJ Motorsports
Maximize your ATV or UTV's engine life with top-quality components from JJ Motorsports. Our selection includes gasket kits, connecting rods, water pump rebuild kits, and timing plugs designed for reliable sealing, strength, and easy installation in demanding off-road conditions. Compatible with Polaris, Can-Am, Honda, and more, these parts ensure peak power, reduced wear, and efficient operation for trail riding or utility work.
Shop trusted brands like Moose Racing for rebuild kits and Winderosa for gaskets. Explore related categories such as ATV/UTV air and fuel for intake upgrades or ATV/UTV drivetrain for transmission enhancements.
Top ATV/UTV Engine Products
- MOOSE UTILITY Clutch Cover Gasket Seal 500-1265-PU – Durable seal for clutch cover protection.
- WINDEROSA Standard Bore Gasket Kit 810585 – Complete kit for engine sealing and rebuilds.
- WORKS CONNECTION Engine Timing Plug 24-590 – Precision plug for accurate timing adjustments.
- MOOSE RACING Connecting Rod MR5026 – High-strength rod for engine durability.
- MOOSE RACING Water Pump Rebuild Kit 821865 – Comprehensive kit for water pump maintenance.
Browse our in-stock inventory below with same-day shipping and expert support. Questions? Contact us for fitment advice!
- Product
- Qty in Cart
- Quantity
- Price
- Subtotal
-
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 specifications with OEM-equivalent components engineered to...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 durability. The PROX Piston Kit 01.2020.250 delivers...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 -
PROX Piston Kit 01.3180.050
PROX
$93.95When your engine's pistons wear beyond safe operating limits, you're looking at catastrophic failure—loss of compression, blow-by, and potential internal damage that can sideline your build. The PROX Piston Kit 01.3180.050 delivers OEM-equivalent...09100893- SKU:
- 09100893
- Availability:
- Ships Same Business Day
- Weight:
- 0.31 LBS
- BORE SIZE METRIC:
- 50.50 MM
- PISTON SIZE METRIC:
- +0.50 MM
- PISTON DIAMETER METRIC:
- 50.50 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- UNITS:
- EACH
- RIDING STYLE:
- ATV
$93.95 -
PROX Piston Kit 01.3180.000
PROX
$93.95A worn or damaged piston directly compromises compression, combustion efficiency, and overall engine reliability—which is why OEM-quality replacement matters. The PROX Piston Kit 01.3180.000 delivers factory-spec performance with precision manufacturing...09100906- SKU:
- 09100906
- Availability:
- Ships Same Business Day
- Weight:
- 0.34 LBS
- PISTON SIZE METRIC:
- STANDARD
- PRODUCT NAME:
- PISTON KIT
- BORE SIZE METRIC:
- 50.50 MM
- RIDING STYLE:
- ATV
- PISTON DIAMETER METRIC:
- 50.50 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
$93.95 -
PROX Piston Kit 01.1480.000
PROX
$99.95Piston failure doesn't just cost you a race—it costs you an engine. The PROX Piston Kit 01.1480.000 delivers OEM-grade reliability with precision engineering, ensuring consistent combustion pressure and thermal stability through the most demanding...09102455- SKU:
- 09102455
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- PISTON MATERIAL:
- ALUMINUM ALLOY
- UNITS:
- EACH
- BORE SIZE METRIC:
- 78.50 MM
- ENGINE TYPE:
- 4-STROKE
- PISTON DIAMETER METRIC:
- 78.50 MM
- PISTON SIZE METRIC:
- STANDARD
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- ATV
$99.95Qty in Cart: 0Quantity:Price:$99.95Subtotal: -
PROX Piston Kit 01.1480.050
PROX
$99.95Engine reliability depends on precision-engineered internals, and pistons are where combustion meets mechanical integrity. The PROX Piston Kit 01.1480.050 restores your engine to OEM performance specifications with Japanese manufacturing precision and...09102456- SKU:
- 09102456
- Availability:
- Ships Same Business Day
- Weight:
- 0.79 LBS
- ENGINE TYPE:
- 4-STROKE
- PISTON DIAMETER METRIC:
- 79.00 MM
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- BORE SIZE METRIC:
- 79.00 MM
- PISTON SIZE METRIC:
- STANDARD
- PRODUCT NAME:
- PISTON KIT
$99.95Qty in Cart: 0Quantity:Price:$99.95Subtotal: -
PROX Piston Kit 01.1480.100
PROX
$99.95When your engine's pistons wear beyond OEM tolerances, you're compromising combustion efficiency, oil consumption, and overall reliability. The PROX Piston Kit 01.1480.100 restores your engine to factory specifications using precision-engineered...09102457- SKU:
- 09102457
- Availability:
- Ships Same Business Day
- Weight:
- 0.75 LBS
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- PISTON SIZE METRIC:
- STANDARD
- PRODUCT NAME:
- PISTON KIT
- BORE SIZE METRIC:
- 79.50 MM
- PISTON DIAMETER METRIC:
- 79.50 MM
$99.95Qty in Cart: 0Quantity:Price:$99.95Subtotal: -
PROX Piston Kit 01.1498.200
PROX
$109.45Your engine's heartbeat depends on pistons that can handle repeated combustion cycles without compromise. The PROX Piston Kit 01.1498.200 delivers OEM-equivalent reliability with precision engineering, ensuring consistent compression, minimal blow-by,...09102474- SKU:
- 09102474
- Availability:
- Ships Same Business Day
- Weight:
- 1.15 LBS
- BORE SIZE METRIC:
- 92 MM
- PISTON DIAMETER METRIC:
- 92.00 MM
- ENGINE TYPE:
- 4-STROKE
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- ATV
- UNITS:
- EACH
- PISTON SIZE METRIC:
- STANDARD
$109.45Qty in Cart: 0Quantity:Price:$109.45Subtotal: -
PROX Piston Kit 01.5805.B
PROX
$134.95Your engine's pistons are the hardworking center of combustion—and worn or damaged pistons mean loss of compression, power, and reliability. The PROX Piston Kit 01.5805.B delivers OEM-spec replacement performance without the dealer markup, engineered to...09105952- SKU:
- 09105952
- Availability:
- Ships Same Business Day
- Weight:
- 0.80 LBS
- RIDING STYLE:
- UTV
- PISTON MATERIAL:
- ALUMINUM ALLOY
- PRODUCT NAME:
- PISTON KIT
- RIDING STYLE:
- ATV
- BORE SIZE METRIC:
- 79.96 MM
- UNITS:
- KIT
$134.95 -
PROX Crank Bearing and Seal Kit 23.CBS22088
PROX
$115.95A compromised crankshaft bearing or seal will rob horsepower, create catastrophic engine damage, and leave you stranded. The PROX Crank Bearing and Seal Kit 23.CBS22088 delivers exact OEM-specification replacements, ensuring your crankshaft runs true and...09240317- SKU:
- 09240317
- Availability:
- Ships Same Business Day
- Weight:
- 1.00 LBS
- UNITS:
- KIT
- APPLICATION:
- CRANKSHAFT
- RIDING STYLE:
- ATV
- STYLE:
- 2-STROKE
- PRODUCT NAME:
- BEARING AND SEAL KIT
- TYPE:
- BALL
$115.95Qty in Cart: 0Quantity:Price:$115.95Subtotal: -
PROX Crank Bearing and Seal Kit 23.CBS23098
PROX
$65.95A complete crank bearing and seal kit is essential for any bottom-end rebuild—it ensures proper clearances, oil distribution, and crankshaft stability under load. Using OEM-spec components eliminates guesswork and guarantees compatibility with your...09240325- SKU:
- 09240325
- Availability:
- Ships Same Business Day
- Weight:
- 1.55 LBS
- PRODUCT NAME:
- BEARING AND SEAL KIT
- TYPE:
- BALL
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
- STYLE:
- 2-STROKE
- APPLICATION:
- CRANKSHAFT
$65.95Qty in Cart: 0Quantity:Price:$65.95Subtotal: -
PROX Crank Bearing and Seal Kit 23.CBS33088
PROX
$70.95A compromised crankshaft bearing or seal can introduce catastrophic wear into your engine's most critical rotating assembly. This PROX kit delivers OEM-specification replacements, ensuring your crank runs with factory precision and longevity—whether...09240340- SKU:
- 09240340
- Availability:
- Ships Same Business Day
- Weight:
- 1.10 LBS
- UNITS:
- KIT
- RIDING STYLE:
- ATV
- STYLE:
- 2-STROKE
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
- PRODUCT NAME:
- BEARING AND SEAL KIT
$70.95 -
PROX Crank Bearing and Seal Kit 23.CBS34000
PROX
$127.95A crank bearing and seal kit is essential maintenance for any high-performance engine—worn bearings increase friction, reduce efficiency, and accelerate wear on your crankshaft. This PROX kit eliminates guesswork by delivering all necessary components...09240345- SKU:
- 09240345
- Availability:
- Ships Same Business Day
- Weight:
- 1.52 LBS
- APPLICATION:
- CRANKSHAFT
- PRODUCT NAME:
- BEARING SET
- UNITS:
- KIT
- TYPE:
- BALL
- RIDING STYLE:
- ATV
- STYLE:
- 4-STROKE
$127.95 -
PROX Crank Bearing and Seal Kit 23.CBS64003
PROX
$156.95A crankshaft bearing and seal kit is essential maintenance for any high-performance engine—neglecting worn bearings leads to catastrophic failure and costly downtime. This PROX kit delivers OEM-specification components that restore your crank to factory...09240367- SKU:
- 09240367
- Availability:
- Ships Same Business Day
- Weight:
- 1.04 LBS
- UNITS:
- KIT
- APPLICATION:
- CRANKSHAFT
- TYPE:
- BALL
- RIDING STYLE:
- ATV
- STYLE:
- 4-STROKE
- PRODUCT NAME:
- BEARING AND SEAL KIT
$156.95 -
PROX Connecting Rod Kit - Yamaha YFM700R 03.2706
PROX
$188.95A connecting rod failure mid-race or trail can leave you stranded—and potentially damage your entire bottom end. The PROX Connecting Rod Kit for the Yamaha YFM700R delivers the precision engineering and durability needed to handle sustained high-RPM...09230631- SKU:
- 09230631
- Availability:
- Ships Same Business Day
- Weight:
- 2.35 LBS
- RIDING STYLE:
- ATV
- PRODUCT NAME:
- CONNECTING ROD KIT
- UNITS:
- KIT
- RIDING STYLE:
- UTV
$188.95 -
PROX Connecting Rod Kit - Yamaha YFZ450R 03.2444
PROX
$183.95A connecting rod failure mid-race means a blown engine and a day off the track—or worse. The PROX Connecting Rod Kit for Yamaha YFZ450R delivers the durability and precision tolerances you need to keep your quad running strong through aggressive riding...09230632- SKU:
- 09230632
- Availability:
- Ships Same Business Day
- Weight:
- 1.90 LBS
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- ATV
- UNITS:
- KIT
$183.95 -
PROX Connecting Rod Kit 03.1300
PROX
$132.95A connecting rod failure can end your race day—or worse, your engine. The PROX Connecting Rod Kit 03.1300 gives you the reliability and precision clearances needed to handle sustained high RPM operation without compromise. This complete assembly arrives...09230278- SKU:
- 09230278
- Availability:
- Ships Same Business Day
- Weight:
- 0.95 LBS
- UNITS:
- EACH
- RIDING STYLE:
- ATV
- PRODUCT NAME:
- CONNECTING ROD KIT
- ENGINE TYPE:
- 2-STROKE
- MATERIAL:
- FORGED STEEL
$132.95 -
PROX Connecting Rod Kit - Yamaha YFZ450 03.2436
PROX
$183.95The PROX Connecting Rod Kit restores critical engine integrity on your Yamaha YFZ450, ensuring reliable power transfer from combustion to crankshaft. Whether you're rebuilding after high-RPM racing or replacing worn OEM components, this complete kit...09230231- SKU:
- 09230231
- Availability:
- Ships Same Business Day
- Weight:
- 1.56 LBS
- ENGINE TYPE:
- 4-STROKE
- PRODUCT NAME:
- CONNECTING ROD KIT
- RIDING STYLE:
- ATV
- MATERIAL:
- FORGED
- MATERIAL:
- STEEL
- UNITS:
- KIT
$183.95 -
PROX Connecting Rod Kit - Honda XL125S 03.1253
PROX
$98.95A worn or damaged connecting rod compromises your engine's reliability and performance, risking catastrophic failure under load. The PROX Connecting Rod Kit for Honda XL125S delivers OEM-quality construction with all necessary components in one complete...09230234- SKU:
- 09230234
- Availability:
- Ships Same Business Day
- Weight:
- 1.20 LBS
- MATERIAL:
- STEEL
- PRODUCT NAME:
- CONNECTING ROD KIT
- ENGINE TYPE:
- 4-STROKE
- MATERIAL:
- FORGED
- RIDING STYLE:
- OFF-ROAD
- UNITS:
- KIT
$98.95 -
PROX Connecting Rod Kit 03.6427
PROX
$179.95A connecting rod is the critical link between your crankshaft and piston, and PROX engineered this kit to handle sustained high-RPM loads without compromise. The 03.6427 arrives as a complete assembly with all necessary components, eliminating the...09230235- SKU:
- 09230235
- Availability:
- Ships Same Business Day
- Weight:
- 1.71 LBS
- UNITS:
- EACH
- ENGINE TYPE:
- 4-STROKE
- RIDING STYLE:
- ATV
- PRODUCT NAME:
- CONNECTING ROD KIT
- MATERIAL:
- FORGED STEEL
- RIDING STYLE:
- OFF-ROAD
$179.95
