Nut by Yamaha

Yamaha UTV/ATV & Side by Side Pistons - Available at buywitchdoctors.com

Product Specifications: Genuine OEM Yamaha Nut, Part # 90179-09379-00.

Keep your machine running like new with a genuine Yamaha Piston paired with premium maintenance parts from buywitchdoctors.com. The piston moves up and down inside the cylinder, compressing the air and fuel mixture and transferring the force of combustion through the connecting rod to the crankshaft. Together with its rings and pin, it seals the combustion chamber, controls oil, and carries heat away from the cylinder, so its condition directly affects compression, power, oil use, and engine life. Riders most often replace a piston after a loss of compression or power, blue smoke or heavy oil consumption, a ticking or slapping noise from the cylinder, scored, cracked, or burnt piston crowns, worn or broken rings, a stuck or seized piston, or damage from overheating, detonation, a dropped valve, or water ingestion.

Why Choose Genuine OEM Yamaha Parts?

Choosing original equipment manufacturer (OEM) parts ensures your vehicle maintains its factory-standard performance, reliability, and fuel efficiency. Genuine parts eliminate the guesswork of aftermarket alternatives, offering a seamless integration with your engine's configuration.

• Exact-Fit Design: Matched to Yamaha's original bolt patterns, sealing surfaces, and dimensions for a leak-resistant fit.
• Factory-Spec Quality: Built to the same standards as the parts installed on your machine at the factory.
• Peace of Mind: Skip the trial and error of universal or aftermarket parts that may not seal or align correctly.

Premium Materials & Precision Engineering

Crafted to strict factory tolerances, these components utilize high-grade alloys and chemical-resistant seals. This specialized engineering withstands harsh off-road vibrations, extreme temperatures, and modern fuel additives, preventing premature wear and leaks. Genuine pistons are made from heat-resistant, lightweight alloy with precisely machined ring grooves, accurately shaped crowns, and carefully controlled skirt profiles, so they seal against the cylinder wall, shed heat, and resist scuffing and cracking through high RPM and constant heat cycles.

Comprehensive Model Fitment (2015-Current)

This genuine OEM part is engineered for a wide range of Yamaha side-by-side (SxS) and all-terrain vehicles (ATV) built from 2015 to the current model year. Please verify your series matches below:

Utility Task Vehicles (UTVs / Side-by-Sides)

• Viking Series: Viking 700 EPS, Viking 700 Ranch Edition, Viking VI EPS
• Wolverine Series: Wolverine R-Spec, Wolverine X2 850, Wolverine X4 850, Wolverine X2 1000, Wolverine RMAX2 1000 (Sport, XT-R, Limited), Wolverine RMAX4 1000
• YXZ Series: YXZ1000R, YXZ1000R SS

All-Terrain Vehicles (ATVs)

• YFZ Series: YFZ50, YFZ450R, YFZ450R SE
• Raptor Series: Raptor 90, Raptor 110, Raptor 700, Raptor 700R, Raptor 700R SE
• Grizzly Series: Grizzly 90, Grizzly 110, Grizzly 700 EPS, Grizzly 700 SE, Grizzly 700 XT-R
• Kodiak Series: Kodiak 450, Kodiak 450 EPS, Kodiak 700, Kodiak 700 EPS, Kodiak 700 SE

⚠️ IMPORTANT DISCLAIMER: Fitment can vary by production date and sub-model trim. Always verify your exact original equipment part number from your vehicle's schematic or consult a certified technician before finalizing your purchase to guarantee flawless compatibility.

Other Popular Parts & Secondary Accessories

• Rocker Arms & Tappets: Rocker arms and tappets transfer motion from the camshaft to the valves. If a valvetrain failure damaged your piston, inspect these parts for wear or damage while the top end is apart.
• Cams & Components: The camshaft and its related parts time the opening and closing of the valves. Check the lobes, bearings, and cam chain components during piston service so valve timing stays accurate.
• Top End Gaskets: Top end gaskets seal the cylinder, head, and related surfaces and are typically replaced whenever the top end is opened. Pair a fresh set with your new piston for a leak-free reassembly.
• Pistons & Components: Rings, wrist pins, and clips complete the piston assembly and are replaced as a set. Install fresh rings and pin clips with your piston so the seal and fit are correct from the first start.
• Engine Cylinders: The cylinder guides the piston and contains combustion pressure, and its bore condition directly affects ring seal. Check the walls for scoring or wear whenever you replace a piston so the new one is not working against a damaged bore.
• Connecting Rods & Components: The connecting rod links the piston to the crankshaft. If the piston failed from a seizure or dropped valve, inspect the rod and bearings for bends or damage before reassembly.
• Engine Gaskets & Oil Seals: Engine gaskets and oil seals keep oil, coolant, and pressure where they belong. Replace them whenever the engine is opened so your piston installation starts clean and leak-free.

Frequently Asked Questions (FAQs)

Q: How do I know when my Yamaha piston needs to be replaced, and how do I confirm the right one for my machine?
A: Watch for low compression, loss of power, blue smoke or heavy oil use, a ticking or slapping noise, and scoring, cracks, burnt spots, or broken ring lands found during inspection. Before replacing it, check the cylinder bore, rings, and valve condition, since damage in any of these can ruin a new piston. Because pistons vary by model, model year, engine, and size, confirm the correct part, sizing, and installation procedure using your Yamaha service manual or factory schematic, or contact us with your model and VIN and we will help you match it.

Q: How do mud, water, sand, and heat affect a piston on the trail?
A: The piston lives inside the engine, so harsh conditions affect it indirectly. Dust or sand that gets past the air filter can scratch the cylinder and rings, water ingestion can bend rods or crack pistons, and heat or low oil can cause scuffing and seizure. Keep your air filter and intake sealed, change oil on schedule, and after deep water crossings check for milky oil or new noises. Follow your Yamaha service manual for correct service intervals, break-in, and water-crossing guidance.

PRO TIP: Learn More about Yamaha OEM vs. Aftermarket Parts

PRO TIP: A Buyer’s Guide To UTV/ATV Internal Engine Components

PRO TIP: Learn more about How to Check Engine Cylinders & Power Loss.

PRO TIP: Learn more about How to Spot a Bad Camshaft & Valves.

Are You Looking to Find Great Places & Adventurous Trails to Ride Your UTV, Side by Side or ATV? Check out these highly recommended places:

• Northern Outdoors
• Imperial Sand Dunes
• Johnson Valley OHV Area
• Gypsum City OHV Park
• Leatherwood Off-Road Park