YZ-4S Servo Mount Post Aluminum S4-203AA Compatible with Yokomo  [S4-203AA]

Aluminum internal servo post tuned for YZ-4S handling

The Yokomo S4-203AA is an aluminum internal servo mount designed for YZ-4S touring car chassis. Built as an inboard chassis post, it locates the servo body to establish a solid link to the steering assembly. This internal post is intended to be combined with the outside mount post and a graphite servo mount plate specific to the YZ-4S chassis to complete the mounting solution.

Fitment guidance: this unit installs inside the chassis and anchors the servo through the internal post interface; the external post and graphite plate are necessary to clamp the servo. Confirm spline alignment and horn orientation before final tightening, and ensure the mount does not interfere with nearby electronics or chassis features.

Tuning note: a machined aluminum internal mount cuts down on unwanted flex between servo and steering linkage, which helps stabilise steering inputs. Slight modifications such as swapping plate thicknesses or inserting shims can be applied to tweak servo height and roll centre without modifying chassis geometry.

Chassis compatibility

Made for YZ-4S style touring chassis and listed as compatible with B-YZ4SF mounting patterns; check your chassis layout before installation.

Choose this aluminium internal mount for a compact, rigid servo mounting solution on YZ-4S cars and combine it with the external post and graphite plate for a full assembly.