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Mountfield Woodruff Key - 4mm X 6.5mm - 16mm Diameter

Mountfield Woodruff Key - 4mm X 6.5mm - 16mm Diameter

This is a genuine Mountfield Woodruff Key with the part number 112139100/0. It features dimensions...

Best current price£1.55from Blueperry agriculture (UK)

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Blueperry agriculture (UK)Castelgarden Key 1121391000
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eBayMountfield Woodruff Key - 4mm X 6.5mm D=16 - 112139100/0
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Product Information

Full details

The Mountfield Woodruff Key (Part #112139100/0) is an essential precision component designed for homeowners and professional technicians maintaining Mountfield garden power equipment. Its primary benefit is providing a secure, reliable connection between the crankshaft and the flywheel or pulley, ensuring engine timing and power transmission remain synchronized. One important caveat is that this is a precision-engineered part; users must verify the specific model compatibility of their machine before installation to prevent mechanical failure.

All features

Model Part Number112139100/0
BrandMountfield

Extended Product Information

FAQs

What are the dimensions of this Woodruff key?

This key measures 4mm x 6.5mm with a 16mm diameter.

Is this a genuine Mountfield part?

Yes, this is a genuine Mountfield Woodruff Key with the official part number 112139100/0.

Do I need special tools to install this?

While the key is small, accessing it usually requires a flywheel puller to safely remove the flywheel from the crankshaft taper.

Can I use this on a different brand of mower?

This part is designed for specific Mountfield models. You should always verify compatibility using your machine's model and serial number.

Why does a Woodruff key fail?

They most commonly fail due to accidental blade impacts, which shock the crankshaft, or if the flywheel nut was not tightened to the correct torque specification during a previous repair.

Troubleshooting

Engine cranks but will not fire after repair

Verify that the Woodruff key was installed correctly in the slot; a misaligned key will throw off the ignition timing.

Flywheel seems loose or wobbly

The key may have worn down or failed. Inspect the key and the slot for deformation and replace if necessary.

Pros and Cons

Pros

  • Ensures precise alignment between crankshaft and engine components
  • Acts as a sacrificial shear element to prevent costly crankshaft damage
  • Manufactured to official Mountfield OEM standards for reliability
  • Easy to install for those with basic mechanical knowledge

Cons

  • Specific to select Mountfield models requiring these dimensions
  • Must be seated perfectly to avoid engine timing issues
  • Requires proper tools like a flywheel puller for access

Setup, Compatibility & Care

To install this Woodruff key, you must first expose the crankshaft taper by removing the flywheel. Ensure that the crankshaft keyway and the flywheel slot are free of debris or burrs before seating the key. The key should sit firmly in the slot without excessive play. When tightening the flywheel nut, follow the manufacturer's torque specifications to avoid shearing the key prematurely or damaging the crankshaft. Regular care involves inspecting the key during seasonal servicing to ensure it has not shifted due to vibration. Always consult your specific Mountfield service manual to confirm part compatibility via the engine model number before beginning the installation.

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