The easiest cleaning method for the i420 is to use the white cap from the spare parts jar to cover the bowl-end of the i420. Place the unit on a level surface (cap-end down) and fill the piece with isopropyl alcohol. Be careful not to open the carb valve, or the alcohol will drain out through the carb. Leave the unit soaking for fifteen minutes, then rinse it thoroughly with warm water and allow it to dry before using.
For regular maintenance, you just remove the expansion chamber, unscrew the nut at the end of the nozzle, and switch screens. You may also choose to remove residue from the nozzle.
In case you have misplaced them them:
1. Extend the Incredibowl all the way, grasp the edge of the carb bearing (ie black piece) with your thumb and forefinger to prevent it from pinching you, and pull the expansion chamber off with a twisting motion.
2. Unscrew the end of the nozzle, remove the spring and the carb bearing
3. Use a pencil, chopstick, or similar item to *push* the glass out from the end of the nozzle
Once you have disassembled, soak your parts in a jar of isopropyl alcohol from 45 min to 8 hours, then rinse with warm water.