How to Installation 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 Installation
Double-check the mating surfaces for cleanliness!
- Install your new O-rings.
- Mount your cylinder head, and install the mounting nuts finger tight.
- I am installing my nuts with ARP Ultra Torque. This is a lubricant that ensures accurate torque values by reducing friction between the nut and the mounting surface. I probably don’t need it for this application, but I’m extra.
- Torque the mounting nuts in the same criss-cross pattern, turning the nuts ¼ turn at a time until you reach torque.
- Torque the mounting nuts to 21 ft-lbs.
- Install the hanger plates, and torque the bolts to 25 ft-lbs.
- This is where I would show mounting my hanger plate, if I had one!
- Install the spark plug, and torque to 15 ft-lbs.
- I don’t have it on video, but trust me, I totally torqued my spark plug.
- Finally, install your coolant hose.
If you have any questions, please let me in the comments, or send me a DM!
| ← Cylinder Installation | Exhaust Valve Governor Removal → |
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