Genuine New 1987-2006 Yamaha Banshee 350 YFZ350 Engine Motor Cases Case

Genuine New OEM Yamaha Banshee 350 YFZ350 Engine Motor Cases,Genuine New 1987–2006 Yamaha Banshee 350 YFZ350 Engine Motor Cases—the real deal straight from the factory. Designed specifically for the iconic Banshee 350, these OEM crankcases offer a precision fit and durable construction that aftermarket alternatives just can’t match.

Whether you’re rebuilding from the ground up, replacing damaged cases, or undertaking a high-performance project, these engine motor cases provide the perfect foundation. Crafted with Yamaha’s legendary engineering, they ensure optimal oil flow, proper alignment of internal components, and long-lasting reliability under harsh riding conditions.

How to Use the Genuine New 1987–2006 Yamaha Banshee 350 YFZ350 Engine Motor Cases

Using the Genuine Yamaha Banshee 350 Engine Motor Cases requires careful installation as part of a complete engine rebuild or replacement process. Here’s a step-by-step overview on how to properly use them:Genuine New OEM Yamaha Banshee 350 YFZ350 Engine Motor Cases

Tools & Materials Needed:

• Full engine rebuild kit (bearings, seals, gaskets, etc.)

• Torque wrench

• Engine assembly lube

• OEM Yamaha service manual (recommended)

• Proper tools for disassembly/reassembly (sockets, pullers, seal drivers, etc.)

• Clean workspace and parts cleaner

Step-by-Step Instructions:

1. Prepare the Work Area

• Set up a clean, organized workspace.

• Ensure all tools and parts are clean and free from dirt or debris to prevent contamination.

2. Inspect the New Engine Cases

• Check for any visible defects or shipping damage.

• Ensure mating surfaces are clean, flat, and free from burrs.

3. Install Main Bearings and Seals

• Using a bearing/seal driver, press in new crankshaft and transmission bearings as per the manual’s specifications.

• Install oil seals in their designated locations using light pressure and even force.

• Apply a thin coat of engine assembly lube to the bearings to reduce friction during the first startup.

4. Begin Engine Assembly

• Lay one half of the engine case flat and begin installing internal components:

  • Crankshaft

  • Transmission shafts and gears

  • Shift forks and drum (as applicable)

• Align everything per factory diagrams.

5. Join the Engine Cases

• Apply high-temperature case sealant (if required) to the mating surface.

• Carefully place the second case half on top, making sure all components remain aligned.

• Insert the case bolts and torque them in a crisscross pattern to factory specs.

6. Continue Full Engine Assembly

• Install additional components such as:

  • Clutch assembly

  • Stator and flywheel

  • Cylinder and piston

  • Top end and side covers

• Follow torque specs and assembly sequence from the Yamaha service manual.

7. Final Checks

• Rotate the crankshaft and transmission shafts to ensure smooth movement.

• Check for any oil leaks, gaps, or misalignments.

• Reinstall engine into the frame, connect carburetors, electrical, exhaust, and cooling system.

8. Break-In and Ride

• Start the engine and allow it to idle.

• Follow Yamaha’s recommended break-in procedure to ensure proper seating of components and long-term reliability.

Important Tips:

• Always refer to the OEM Yamaha Banshee 350 service manual for torque specs, sequences, and diagrams.

• Replace all worn or damaged parts during rebuild—don’t reuse old bearings or gaskets.

• Use OEM or high-quality aftermarket rebuild kits to complement the new engine cases.

By following proper installation practices, your Genuine New Yamaha Banshee 350 Engine Cases will provide years of high-performance riding and reliability. Whether you’re restoring a classic or building a race-ready quad, using these cases ensures your engine starts with the strongest foundation possible.

Uses:

The Yamaha Banshee 350 YFZ350 Engine Motor Cases serve as the structural foundation of the engine. Their primary functions include:

• Housing rotating engine components such as the crankshaft, transmission gears, and bearings.

• Facilitating proper oil and coolant flow throughout the engine to ensure thermal stability and lubrication.

• Maintaining precise alignment of internal components to ensure peak engine performance.

• Providing mounting points for external engine parts like the clutch, stator, and cylinder.

These motor cases are essential for:

• Full engine rebuilds

• Performance upgrades

• Restoration of vintage Yamaha Banshees

• Replacing worn or cracked cases from damage or age

Properties:

The Genuine Yamaha engine cases are engineered with high-performance specifications in mind. Key properties include:

• OEM Precision Fitment: Designed by Yamaha to exact tolerances for flawless compatibility with all 1987–2006 Banshee 350 YFZ350 models.

• High-Strength Aluminum Alloy: Offers excellent strength-to-weight ratio, heat dissipation, and corrosion resistance.

• Enhanced Oil Passages: Internal channels ensure proper oil delivery to all engine components for lubrication and cooling.

• Machined Sealing Surfaces: Ensures leak-free connections with gaskets, seals, and covers.

• Reinforced Mounting Points: Engine mounts are reinforced to withstand extreme stress from racing or off-road use.

Manufacturing Process:

Genuine Yamaha engine cases are produced using advanced manufacturing techniques that ensure durability and accuracy. The key steps in the process include:

1. Die Casting or Gravity Casting:

   • The engine case begins as a molten aluminum alloy, poured or injected into high-precision molds.

   • This process forms the basic shape while maintaining consistent wall thickness and internal structure.

2. Heat Treatment:

   • Castings undergo thermal treatment to improve mechanical strength, fatigue resistance, and dimensional stability.

3. CNC Machining:

   • Critical surfaces—such as bearing housings, bolt holes, and mating flanges—are CNC machined to precise tolerances.

   • This ensures smooth engine assembly and optimal alignment of internal components.

4. Inspection & Quality Control:

   • Each case is rigorously inspected for defects, warping, porosity, and alignment.

   • Yamaha’s strict OEM standards ensure only flawless parts make it to final assembly.

5. OEM Stamping & Part Numbering:

   • Cases are stamped with Yamaha’s logo and unique part numbers for traceability and authenticity.

Conclusion:

The Genuine New 1987–2006 Yamaha Banshee 350 YFZ350 Engine Motor Cases are more than just metal housings—they’re the critical backbone of a high-performance two-stroke engine. Built using Yamaha’s factory-grade materials and processes, these cases offer unmatched reliability, performance, and fitment, making them the top choice for serious riders, builders, and restorers.