1975 Yamaha YZ125B

Model Information

Yamaha had a great opportunity to build on their first year YZ125A, and they did but it would come as a mid-year release in the fall of 1975. In the meantime, they had to provide something to their dealers; introducing the YZ125B, a yellow YZ125A.

Even though they could have made improvements in the reliability and suspension departments having had a year on the YZ125A, they invested those improvements in the “C” model which would blow everyone away. That being said, in a Cycle Guide shootout with the YZ125B, the test bike had to go back to the factory one day into testing due to a faulty idler gear. It wasn’t a fluke, as in a Dirt Bike magazine test between the Yamaha MX & YZ and the Honda CR125M1 the idler gear on the YZ froze and had to also go back to the factory after 1 day of testing.

According to the test, it could have been worse. Apparently the throttle on the MX stuck wide open on a fast section of the track. When the tester went for the kill button, he realized that it wasn’t hooked up and went down pretty hard. The crash damaged the forks enough that it too had to be sent back to the factory. And when they got it back, the choke didn’t work!

1975 Yamaha YZ125B

I love this bike because it’s a rare half-year model that had a very limited production. Very few of these bikes were sold because a) the only significant change from the 1974 model was the new yellow color, and b) the fact that everyone was anxiously awaiting the YZ125C monoshock (introduced in late 1975).

I had heard of this bike from a friend of a friend and purchased it in 2008 from the owner who lived in Utah. This was a good example of a bike that was originally purchased for riding around a farm, trails, or nearby field. The frame and wheels were straight, the tank and pipe were perfect, and all original parts were intact. However, this bike was still in need of a restoration. Some of the most difficult NOS parts to find for this model are; gas tank, pipe, rubber tank pads, Velcro tank straps, seat, and plastic.