The disclosed technology relate to a device and system that include an outdoor power equipment power unit or cart configured to releasably couple a number of different interchangeable attachments or work implements to a common power unit, where some attachments include and/or require operator presence control, while other attachments do not include and/or require operator presence control. The outdoor power equipment power unit includes a power transfer coupling member operatively coupled to the drive shaft and configured to transfer rotational power to the associated attachment; and an operator presence actuation member operatively coupled to the operator presence control member, the operator presence actuation member configured to rotate in response to user actuation of the operator presence control member.