The XL motor is diff than the D1. The D1 motor -- still a
Fasco, I believe, has a fan inside the main motor housing.
On the XL, the fain is outside the main motor housing and
under the black cap that functiions as an air diverter to
send the fan outfout over the heat sink located around the
tim of the motor. This bigger motor need more cooling than
the D1 motor. If you remove the 4 screws holding the cap
in place, the heat sink will be visible andthe centrifugal
fan will be in plain sight at the top of the motor. It's
held to the shaft with a hex screw. If the screw is loose,
the fan might not turn at speed. IF the fan is missing,
then maybe you can get Vortex to jsut sent a fan -- it
would be easy enough to install.