From Janome.com:
You should not oil your machine very often. Perhaps once a month if you sew a lot. There is a little wick under the bobbin case - this is where you put your scant drop of sewing machine oil. To get to it you take off the throat plate, remove the bobbin case and you will see the wick. You will need to take the throat plate off and brush out any fuzz, there are small vacuum tools available at a store that sells sewing supplies or perhaps at your dealers that can be used to vacuum a little deeper inside the bobbin area. DO NOT use canned air as you can blow that debris deep inside and under the moving parts in your machine. Leave the deep cleaning for your trip to the technician when you feel it is time. You should do this at the minimum every 2 years but every year is better. These machines are very reliable and shouldn't cause you any grief.