Need to oil the blower motor but don't know where to add the synthetic oil?

If it's a newer furnace, odds are the bearings are sealed. No adding oil to these types of motors. If it does have oil ports, there will be one on both ends of the motor on the round edge.

Aven't seen an oiled motor in a while. Are you sure there are holes or lift caps for oiling? How old is the unit/motor.

I have a model 9007590 H/C Blower that just won't pick-up speed anymore is time for a new one?

Hi jram. It may be time for a new motor, but there is also a good chance that your motor run capacitor is weak. I would check or replace the capacitor with an exact uf/mfd rating first. Capacitors normally run between 6 and 12 dollars, so its worth a shot vs replacing the motor, which may run upwards of a hundred bucks, or even substantially more depending on the motor in question.