:CB400F ST-1M camshaft (408cc, 398cc) [1]

Below is the Yoshimura product page description---------------------

*The profile is the same as ST-1.

The above cam specs are derived from the camshaft design values.
Due to manufacturing reasons, there may be slight variations between batches.
The ST-1M can be installed as a standard port-on, but if more precise accuracy is required, we recommend re-timing the valves for each vehicle.

Since its discontinuation, we have received many requests for the re-release of the CB400Four ST-1 camshaft, and it has now been re-released as the ST-1M, using a machined manufacturing method.
The camshaft is an important part that determines the engine characteristics. Come experience the engine feeling created by Yoshimura.

[What is a Yoshimura camshaft?]

■Unique cam profile settings Yoshimura's camshafts have cam profiles designed using our unique know-how.
The design of the profile begins with knowing the specifications of the standard engine. The engine speed and characteristics are estimated, and the characteristics of the Yoshimura camshaft profile are determined based on these.
Next, the determined profile characteristics are expressed numerically.

From shape to numbers...Yoshimura's many years of know-how has led to a unique profile.

A prototype camshaft with the resulting profile is then made and installed in the engine to check whether it actually produces the desired characteristics.
If the expected characteristics are not achieved, the design has to be started again from the beginning.
After repeating this series of steps, Yoshimura's unique cam profile is derived.

■Comprehensive production management Yoshimura manages consistent production, including centering.
We also paid close attention to the material of the camshaft that reproduces the profile, and it is machined from scratch in-house.
We do not perform cam lobe build-up or shaping, as we believe that applying heat to the product will cause distortion, deformation, and damage to the strength of the camshaft itself.
Then, to make the cam hard enough to fit the engine, we select and apply the most suitable heat treatment method from a variety of options.
Unique cam profile design + consistent production management - this is Yoshimura's commitment to camshafts.