This is from the site Bring a Trailer (https://bringatrailer.com/) ...
This 1974 Yamaha YZ125 is equipped with a Noguchi performance package. It was raced by David Kelly in the AMA when new and reportedly received a restoration in 2010. Power is from a race-tuned 125cc single-cylinder paired with a 5-speed gearbox. The bike was recently acquired by the selling dealer out of a private collection and received a fluid change, inspection, carburetor rebuild, and more earlier this month. This YZ125 is eligible for AHMRA competition and is now offered in Connecticut with a transferable Vermont registration.
The factory fenders, side panels, and gas tank were refinished in the original white during the 2010 restoration. Noguchi graphics have been added, and a small split is present on the back of the aluminum tank, which has been patched.
Gold anodized rims are laced to the factory drum brake hubs. The brakes, cables, chain adjusters, and wheel bearings were reportedly addressed during the recent service.
The bike is equipped with the following Noguchi Stage II engine components, which raise output to a reported 30 horsepower.
- Chromed alloy cylinder
- Alloy cylinder head
- Head gasket
- Cylinder base gasket
- Piston w/ pin and clips
- Piston rings
- Large-volume carburetor manifold
- Reed valve gasket
- Large-volume reed valve
- Mikuni 28mm carburetor
- Main jets
- Carburetor clamp
- High-sweep exhaust pipe
The service earlier this month included fresh Redline MTL oil for the 125cc engine and 5-speed gearbox, as well as a new air filter, carburetor rebuild, and replacement reeds. A recent cold compression test revealed 125 psi and a strong spark.
Taneharu Noguchi was a Yamaha GP Racer turned team manager, and later factory-authorized performance parts manufacturer. His works performance kits were used by AMA national motocross and road racing teams.