✅ How to Use 1987–2006 Yamaha Banshee 350 Complete Engine Rebuild Parts

⚠️ Important Note:

• This guide assumes you have basic mechanical knowledge and the proper tools for engine work.

• Always refer to a Yamaha Banshee 350 service manual for torque specs, clearances, and step-by-step procedures.

🛠️ Tools & Supplies You’ll Need:

• Torque wrench

• Socket and wrench set

• Engine stand (optional but helpful)

• Micrometer/calipers

• Assembly lube

• Engine cleaner/degreaser

• Shop towels

• Yamaha Banshee 350 service manual

✅ Step-by-Step Process:

1. Preparation

• Disconnect battery and drain all fluids (oil and coolant, if applicable).

• Remove the engine from the ATV frame.

• Clean the exterior of the engine to prevent contamination.

2. Disassembly

• Remove the top end (cylinder, piston, head).

• Split the engine cases carefully using a case splitter.

• Remove crankshaft, bearings, seals, and transmission components if necessary.

3. Inspection

• Check all parts for wear or damage.

• Clean all components thoroughly.

• Inspect cylinder walls, crankshaft journals, connecting rods, and transmission parts for scoring, cracks, or wear.

4. Install New Components (From Rebuild Kit)

🔧 Bottom End Installation:

• Install new main bearings and crankshaft into the cleaned engine cases.

• Use assembly lube where needed and ensure proper alignment.

• Install new oil seals, ensuring correct orientation.

🔧 Top End Installation:

• Install new pistons, rings, and wrist pins.

• Slide the cylinder over the new pistons, being careful not to damage the rings.

• Use a ring compressor if needed and apply 2-stroke oil to the piston skirts.

🔧 Gasket & Seals:

• Replace all old gaskets and seals with the new ones from the kit.

• Clean gasket surfaces before applying new gaskets.

• Use gasket sealer where specified by the service manual.

5. Reassembly

• Reassemble the engine cases, torquing all bolts to factory specs.

• Install top-end components and torque cylinder head bolts in a criss-cross pattern.

• Reinstall the engine into the ATV frame.

• Connect all electrical and fuel components.

6. Break-In Procedure

• Use a proper break-in oil for two-stroke engines.

• Start the engine and let it idle for a few minutes, checking for leaks or abnormal noises.

• Follow a proper break-in cycle (e.g., heat cycles and varied throttle for the first few hours of riding).

• Avoid full throttle or extended high RPMs during break-in.

✅ Post-Rebuild Checklist

• ✔️ Check for oil or coolant leaks

• ✔️ Verify proper spark plug operation

• ✔️ Ensure carburetor is tuned for optimal performance

• ✔️ Confirm engine temperature and idle speed are stable

• ✔️ Monitor compression levels after break-in