YS Engine YSS7138 Regulator Assembly Spring Replacement for Regulator Assemblies  [YSS7138]

Spring replacement procedure

The YS Engine YSS7138 regulator spring is a direct replacement spring intended for regulator assemblies used with YS Engine equipment. It is supplied as a single service item for users refreshing or repairing the regulator unit.

The spring determines preload on the regulator and influences idle and throttle return characteristics; swapping springs is a common approach to make fine adjustments to engine response without changing larger regulator components. The part is sold as an individual spring element to be fitted into the regulator mechanism.

To replace, open the regulator assembly to access the spring area, remove the existing spring carefully, and install the YSS7138 in the same orientation. Always verify throttle operation at idle and full travel on a bench before field testing to confirm expected behaviour.

This spring is sold individually for maintenance and minor tuning and is intended only for model use; it is not for full-scale vehicles.