Yamaha YZ125 Engines / Parts

ProX has a great line of parts for your YZ125. They have piston kits that have been precisely manufactured with low-expansion, low-friction piston alloy, using state of the art equipment. This installation-ready replacement piston kit comes with piston rings, a wrist pin, and circlips. ProX also has a Connecting Rod kit that is made of only the strongest alloy, to OEM specs so you have an easy installation and great performance. These kits come with a crankpin, big end bearing, small end bearing, and washers.

Hot Rods has a Crankshaft Assembly that comes with a Hot Rods connecting rod. Having been manufactured in a factory to OEM specs, these ready to install cranks will give you performance that your OEM parts can’t.

Wiseco has replacement engine parts for your 125, too. They have forged, one-piece pistons that are extremely stronger than your typical cast pistons. The pistons have been made from aerospace-grade alloy, and each top-end piston kit comes with a top-end gasket kit, ring kit, and alloy pin giving you everything you need.