Planning a Crankshaft Replacement on Banshee, Blaster, RD350, or RZ500? Read Up

Nov. 11, 2024

When it comes to high-performance vehicles like the Yamaha Banshee, Blaster, RD350, and RZ500, replacing the crankshaft is a key upgrade that can breathe new life into your ride.

Whether you're aiming for a stock rebuild or boosting your machine's power output, a new crankshaft is essential for restoring performance and reliability. In this guide, we’ll explore the process and considerations for each model, helping you get back on the track or trail with confidence.

So, let’s break it down for replacing cranks on Banshee , Blaster , as well as 2-stroke motorcycle models RD350 and RZ500, then provide a comprehensive step-by-step for quads.

For Yamaha Banshee: A Twin-Cylinder Legend

The Yamaha Banshee, with its iconic 350cc two-stroke twin-cylinder engine, is known for its power and acceleration. Replacing the crankshaft on a Banshee can be a complex process, but it’s worth the effort, especially if you’re experiencing vibration, knocking noises, or poor engine performance.

Steps to Replace a Banshee Crankshaft:

  • Disassemble the Engine: Start by removing the plastics, disconnecting the battery, and pulling the engine from the frame. You’ll need a flywheel puller to remove the flywheel safely.
  • Split the Crankcase: Use a crankcase splitter tool to access the crankshaft. Be careful with the crankcase mating surfaces, as any damage can lead to oil leaks.
  • Install the New Crankshaft: At Vito’s Performance, we offer high-quality replacement crankshafts designed to fit perfectly, ensuring smooth operation and long-lasting durability.
  • Reassemble and Test: After reassembly, refill with new oil and test the engine for any unusual noises or issues.

Pro Tip: Upgrade to a high-performance crankshaft for increased durability, especially if you’ve made modifications like a big bore kit or aftermarket exhaust.

For Yamaha Blaster: Lightweight and Powerful

The Yamaha Blaster, a 200cc two-stroke ATV, is favored by off-road enthusiasts for its nimble handling and peppy engine. Replacing the crankshaft on a Blaster can be a great way to boost performance, particularly if the original has worn out after years of hard riding.

Steps to Replace a Blaster Crankshaft:

  • Inspect the Bearings: Worn crankshaft bearings can cause major engine damage. Replace them along with the crankshaft for optimal results.
  • Use Quality Seals: Cheap or worn-out seals can lead to air leaks and lean engine conditions, risking a seizure.
  • Torque Specs Matter: Follow the specific torque specifications found in the Blaster’s service manual to avoid over-tightening, which can warp the crankcase.

For Yamaha RD350: The Street Racer’s Favorite

The Yamaha RD350 is a classic two-stroke motorcycle revered for its speed and agility. Replacing the crankshaft on an RD350 is more involved than on an ATV due to its twin-cylinder setup and road-going nature.

What Makes RD350 Crankshaft Replacement Different?

  • Precision Alignment: With its twin-cylinder design, the RD350 crankshaft must be perfectly aligned. Any misalignment can result in vibration and uneven power delivery.
  • Balancing the Crankshaft: For those seeking top performance, consider a balanced crankshaft. This upgrade reduces vibration and improves throttle response.
  • Gasket and Seal Replacement: Never reuse old gaskets and seals. Fresh seals ensure proper compression and help maintain engine efficiency.

Vito’s Performance offers crankshafts specifically designed for the RD350, providing enhanced strength and reliability for high-performance builds.

For Yamaha RZ500: The V4 Powerhouse

The Yamaha RZ500, a rare and powerful V4 two-stroke motorcycle, demands attention when it comes to engine maintenance. Replacing the crankshaft on an RZ500 is a task best left to experienced mechanics, but it’s a must for restoring this bike’s full potential.

Challenges of Replacing an RZ500 Crankshaft:

  • Complex V4 Configuration: The RZ500’s V4 engine is intricate, with two separate crankshafts that need precise synchronization.
  • Crankshaft Phasing: The V4 design requires careful phasing of the crankshafts to ensure smooth operation. Using a crankshaft alignment tool is crucial.
  • High-Quality Parts: Due to the rarity of the RZ500, sourcing a reliable crankshaft can be challenging. At Vito’s Performance, we provide top-tier crankshafts that meet or exceed OEM specifications.

Pro Tip: Upgrading to a race-spec crankshaft can significantly improve the power delivery of your RZ500, making it a true standout at any event.

Replacing Cranks on Quads: Step-by-Step

Replacing a crankshaft on a quad is a challenging and time-consuming task, typically requiring advanced mechanical skills and a full set of tools. If you feel confident with engine repair, this comprehensive guide may be useful.

Tools Needed:

  • Complete socket set
  • Torque wrench
  • Flywheel puller
  • Crankcase splitter (optional but helpful)
  • Engine stand (recommended)
  • Rubber mallet
  • Screwdrivers
  • Gasket scraper
  • Crankshaft installer (or press)
  • Replacement crankshaft
  • New gaskets and seals
  • New bearings (if needed)
  • Engine oil
  • Engine manual (for torque specs and specific details)

Step-by-Step Guide:

  1. Preparation: Remove the quad’s plastics and any parts obstructing access to the engine, including the fuel tank. Disconnect the battery to avoid any electrical issues.
  2. Remove the engine from the quad: Drain the engine oil and coolant (if liquid-cooled), disconnect all wiring, fuel lines, and coolant hoses attached to the engine. Unbolt the engine from the frame and carefully lift it out.
  3. Disassemble the engine: Place the engine on an engine stand or a clean surface, remove the cylinder head and cylinder barrel. Be careful with the cylinder head bolts and follow the correct loosening sequence. Take off the flywheel and any other components attached to the crankcase (timing chain, clutch, etc.).
  4. Split the crankcase: Unbolt the crankcase by halves and carefully split the crankcase, taking care not to damage the mating surfaces.
  5. Remove the old crankshaft: Take out the old crankshaft, along with any worn bearings.
  6. Install the new crankshaft: Press in the new crankshaft bearings (if applicable), ensuring they are seated properly, and position the new crankshaft into the crankcase half.
  7. Reassemble the engine: Apply new gaskets and seals to the crankcase halves, reassemble the crankcase, tightening bolts in a crisscross pattern to the correct torque specifications. Reattach the stator, flywheel, timing chain, and other components. Reinstall the cylinder and cylinder head.
  8. Reinstall the engine: Place the engine back in the quad’s frame and secure it with bolts. Reconnect all wiring, fuel lines, and coolant hoses. Refill the engine with oil and coolant.
  9. Test the engine: Double-check all connections and ensure everything is torqued properly. Start the engine and let it idle. If it runs smoothly, reassemble the remaining plastics and parts on the quad.
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