Typically, the stair master should gradually increase in speed from lower levels. If it's not speeding up until level 8, there might be a malfunction. It could be a setting or technical issue. Have you checked the manual or contacted customer support?
Hi,
please increase the steepness of the floor of the machine to start. If this does not work, then your partner might start off each use of the machine by adding a small textbook to the floor to overcome the issue and allow the book to slide of as the treadmill moves. From there on as long as she's moving the treadmill should continue to function. In the mean time, you can schedule servicing on the machine to recalibrate it.
Thank you.
There are several potential causes. One is that the clutch mechanism that allows the steps to 'pump' the flywheel has suffered an internal failure, possibly a sprag failure; another is that the drive from the clutch to the resistance has broken (I don't recall if that is a chain or belt on the 4000)
Rather than troubleshoot from distant memory, here's a link to the service manual:
https://www.manualslib.com/products/Stairmaster-4000-Pt-Series-3234686.html
