Your capacitor is too small. The new motor you list requires a 10 MFD capacitor to run at 240 VAC. Since the OEM capacitor in the unit is only 5 MFD, the new motor will randomly run backward and it will run with far less than its rated HP.
Also, you should connect the new motor to run on LOW (red wire). These universal replacement condenser fan motors are not really multi-speed motors. They are actually multi-horsepower motors. At the low setting, your new motor is 1/5 HP. The OEM motor was 1/10 HP, and the fan blades for your condenser are sized for the 1/10 HP motor. When you install the correct new capacitor for your new motor, I think you will find that your condenser fan runs faster with the new motor on LOW than it did with the OEM motor.
You had (maybe sub-optimal) working air, so the holes (unless new) are probably not the primary cause. I imagine your evaporator coil (the coil inside the interior air handling unit) has frozen over.
This typically happens when the airflow over it is restricted, but it can happen when the refrigerant has leaked out of the system. Air restriction prevents warm air from heating the coil, which will eventually freeze the humidity out of the air creating an insulating block of ice. Low refrigerant levels super cool the coil creating the same freezing over.
So, replace (or temporarily remove) the dirty air filter. Open all the vents. Turn your AC off for a long enough period of time to melt the ice (typically 4 to 5 hours, but sometimes less). Then turn the unit on. If airflow is restored, you know the symptom of your problem.
If you don't freeze up again, it was likely an airflow problem you just fixed with the new air filter and by opening the vents. Occasionally the interior fan is not turning on, so opening the interior unit is a good idea for visual inspection.
If air handling seems fine and it freezes up again, call a professional to find the leak in your system, have the leak repaired and then get your system recharged with refrigerant. Many pros like to charge the system and run; but, refrigerant doesn't degrade or get "used up". If you're low, there's a leak. Get them to find and fix it now or risk calls and extra strain on your system (which could shorten the life of your system).
Opening the unit involves removing the tape around the panel (it is typically metal duct work tape, so use gloves to avoid cutting your hands). The tape only seals the unit for air tightness. There are screws on the panel. When done, re-tape with metal tape for air tightness.
Keep in mind that the root cause is sometimes electrical. If so, you'll notice the interior fan not is not turning on. There are additional circuit breakers on the air handling unit, as well as the possibility of burnt out control circuitry, corroded / disconnected wiring, etc. It is a good idea to turn the breakers off and on just to assure it's not the cause.
I'd fix the duct work, but to save you money on your AC bill, it's not a likely root cause.
Best Answer
The orifice will need to be changed. The question is whether the evaporator is rated for the 410 pressures. In the early days the R22 evaporators could not contain R410, but after 410 came out mfg’s started making heavier coils that could support 410 but R22 was cheaper and we had experience with it so we continued using it even though it was being phased out.
If the evaporator coils are rated for R410 sure go ahead and use it, but as I told another person on this forum today I know of a company that upgraded an old R22 system it worked until a hot day and the evaporator coil exploded causing damage to the air handler and the home having to be evacuated (Freon is heavier than air and can kill especially with a closed up house). The fire department aired out the house but the oil in the air handler, furnace and ducts had to be removed before the home could be occupied because of the smell.
So I would check the model of the evaporator to make sure it has an acceptable pressure rating. If so, change to the appropriate size orifice. This won’t be as efficient of a system as it could be but it can work if the pressure rating is there.