1994 – 2001 Yamaha YZ125 – Cylinder Head – Removal

How to Remove your 1994 through 2001 Yamaha YZ125 Cylinder Head

The Tools You Will Need

• Foot-Pound Torque Wrench → https://amzn.to/3FVEdr3
• Safety Glasses → https://bulltru.com
• Dremel with Sanding Disc → https://amzn.to/407t6l3
• Brake Cleaner → https://amzn.to/4jv9v7a
• Feeler Gauge → https://amzn.to/4hd7qen
• ARP Ultra-Torque → https://amzn.to/48HCu52
• 13/16” Box Wrench
• ⅜” Socket Wrench

The Specialty Tools You Will Need Are:

• Machinists Straight Edge → https://amzn.to/4g4fSM1

The Parts You Will Need

• Full O-Ring Kit → https://amzn.to/47nkjiN
• Inner O-ring PN: 93210-63442-00
• Outer O-Ring PN: 93210-90785-00

Pre-Service Notes

• I recommend opening the Service & Torque Specs in a new tab for easy reference.
• If you need parts and tools, make sure to buy them here! → https://amzn.to/4h4lDKq
• Pictures with captions are below after step.
• If you need any help don’t hesitate to ask!

Cylinder Head Removal

• Start with your bike on a stand with the body and exhaust removed, and the cooling system drained.
• Remove the coolant hose and spark plug from the cylinder head.
• Remove the engine hanger bolts, and keep track of which direction they are facing on the mounting plates.
• Mark the head nuts with 1 through 6 to follow a consistent criss-cross pattern.
• Remove the spark plug.
• Loosen the cylinder head nuts ¼ turn at a time to avoid head warp, with as many passes as you need.
• You may need to hose your head nuts down with penetrating oil.
• Remove the nuts and seal washers.
• Lift the cylinder head off the cylinder, followed by the o-rings.
• Set your cylinder head aside, and set the old o-rings in the trash.

If you have any questions, please let me in the comments, or send me a DM!

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