Hoover Runabout Supreme Repair

Have a Hoover Runabout Vaccum cleaner for 6 years. Recently, the elecric motor began revving extremely high (high RPM) and loud when the cleaner is turned on. I guessed that the belt was worn so I replaced it. No success... Any ideas??
Thanks in advance
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.