Do you have an electric PTO clutch? If so, there is no need for idler pulleys. Please post your units model number, so we know what you are talking about.
#4
reynoldston
The MTD deck moves forward as it is raised making the belt loose, then as this happens two brake pads come in contact with the two mower deck pulleys stopping the blades. No the MTD doesn't have a electric clutch. The OP is right only three pulleys and a very simple system. You will see the brake pads mounted to the step plates.