How to Start a Pressure Washer
Prevent pressure washer performance problems with this article's steps for correct pressure washer setup. Correctly clearing air from your pressure washer also prevents damage.
That is a Torx head screw. I would think the size is probably a 20. The wrenches can be purchased separately or in a set. The following link is an example of a set that is available. Folding Torx Key Set.