I have a precor 92.1i unit and it is emitting black dust from the back left quarter. I have inquired at the store where I purchased the unit several years ago and they advised me that there had been

SOURCE: ???maximum user weight for Precor 9.45i

Normally most home treadmills are 250-300lb user capacity.
Call Precor with your model # and S/N and they can tell you exactly.

SOURCE: wax or silicone on my 10+ year old Precor M9.21

Use silicone to lube your treadmill.

SOURCE: err22 showing.How can I start?

The speed sensor is a hall effect sensor that emits a pulse when a flywheel lobe passes between
its transmitter and receiver. The speed control circuit processes the pulse train emitted by the
speed sensor. The speed sensor signal is a real time representation of the operating speed of
the treadmill. The speed control circuit compares the real time speed (speed sensor output) with
the speed that it expects the treadmill to be operating at and acts accordingly to control treadmill
speed or initiate an error code sequence, if necessary. Typically, if a problem exists with the
speed sensor the drive motor will operate (perhaps only briefly) before a speed related error
occurs (errors 20-26).
1. Set the treadmill circuit breaker in the “on” position. Using a DC voltmeter, measure
the voltage between terminal 3 of J2 (green wire) and terminal 4 of J2 (black wire) on
the lower PCA. Slowly, rotate the drive motor flywheel. The voltage should read
approximately 5 Vdc when a flywheel lobe is between the speed sensor “legs” and
approximately 0.25 Vdc when a flywheel lobe is not between the speed sensor “legs”

2. If the voltages in step 1 are correct, go to step 5. If the voltage in step 1 is 0 Vdc or
significantly low when a flywheel lobe is between the speed sensor “legs, continue with step
3.
3. Measure the voltage between terminal 1 of J2 (red wire) and terminal 4 of J2 (black wire) on
the lower PCA. The voltage should read approximately 5 Vdc.
Flywheel
Speed
Sensor C954, C956 Treadmill
Page 1-24 Page 24
4. If the voltage is missing or significantly low, disconnect the speed sensor plug from the lower
PCA. Measure the voltage between pins 1 & 4 of the J2 plug on the lower PCA. If the
voltage is approximately 5 Vdc, replace the speed sensor. If the voltage is missing or
significantly low, replace the lower PCA.
5. At this point the speed sensor output is good, but a speed error occurs. There are two
potential causes for this condition. They are upper PCA or lower PCA. There are no good
means of troubleshooting these components other than substituting known good
components. Replace only one component at a time. If the component that you replaced
does not correct the problem, replace the original component. Try substituting the lower
PCA first then the upper PCA, if necessary.

tips extracted from the technical manual Precor956

SOURCE: The back roller on my

In looking at the parts list for the Precor 9.20s on fitnessrepairparts.com it looks the rear roller for the machine is currently available although it is not cheap. Doesn't look like treadmilldoctor.com has one.

SOURCE: Where can I find a Precor 9.21 treadmill motor cover?

Do you know which version of the Precor 9.21 you have? There are a few different versions you can view here. Click on your version to view the parts list and look for "Cover, Motor" or "Motor Cover".

For instance, if you have the 9.21 (AYYZ), the proper motor cover is this part #5019749

However, this part #5005569 is listed as the proper motor cover for the 9.21 (F5), 9.21i (2X), 9.21s (F6), 9.21si (2Y), and a couple others. Make sure you have matched up your exact model number with the motor cover you need so do you not order the wrong part.