To me it sounds like you haven't gotten the oil in all the locations needed.
BTW I don't use 'oil' - I use Tri-flow. You can pick up Tri-flow at a bike shop.
You might want to go back to all the areas you oiled and, using a q-tip dipped in alcohol, carefully remove the oil you put in there. Don't let the alcohol touch painted areas. Once all the oil is gone, use the Tri-flow. It comes with a really nice long nozzle to get in all those places that are hard to reach.
Tri-flow it. Let it sit over night. Next day run it for a few minutes. Tri-flow it again. Let it sit over night. Next day it should be running a LOT better. If it still slows down, get out your hair dryer and blow some hot air on all the spots you oiled and run it again.
Of course this is all conditioned that there is nothing wrong with the electrical system....
Shari