Slipper Main Shaft S4-303MSA for Yokomo YZ-4SF  [S4-303MSA]

Main slipper shaft compatible with YZ-4SF

The S4-303MSA serves as a replacement main shaft built for the slipper assembly used on YZ-4SF models. Its purpose is to retain slipper parts while preserving the designed slip characteristics that protect the drivetrain under load.

This item is defined for chassis code B-YZ4SF, so confirm your chassis identifier before purchasing. The part is described as a standard replacement, not a performance modification, and is intended to match original fitment for the YZ-4SF slipper system.

Fitting the shaft typically involves partial removal of the slipper unit to extract the old shaft and fit the new one, checking engagement and alignment of pads or springs on reassembly. Use it as a direct swap to return the slipper to factory positioning during service or adjustments.