How To Repair The Carburetor on Your 1994 - 2001 Yamaha YZ 125. This carburetor is a Mikuni TMX38 found on the 2001 Yamaha YZ125. The 1995 - 2000 YZ125 came with a TMX36. They are very similar, so this Service will cover both models.
The 1994 Yamaha YZ125 came with a Mikuni TMX35, which is significantly different from the TMX36, so this Change will not apply to that model directly, but it will be close enough.
The TMX line of carburetors has two weak points; the jet block gasket, and the float valve O-ring. So before you even take your carb off your bike, I recommend you order the JD Jetting JDMK05 – Mikuni TMX Jet Block Gasket Kit. → https://jdjetting.com/product/jdmk05-mikuni-tmx-jet-block-kit/
It comes with the gasket, 2 O-rings, and the Torx bit needed to remove the jet block.
The Tools You Will Need To Rebuild Your Mikuni Carb: Philips Head Screwdriver 6mm Socket (Main Jet & Needle) 14mm Wrench (Choke Knob) 17mm Wrench or Socket (Bowl Drain) Needle-Nose Pliers Shop Towels
The Parts You Will Need To Service Your Carburetor: Jet Block Gasket Needle Seat O-ring Bowl Gasket (Maybe)
Pilot air screw factory settings: 1995 - 2001 - 1 and 3/4 1994 - 1 and 5/8
