Squirt,
You need to remember that every place has different laws covering them. That means that just because your township requires it as a revenue producer, my city does not.
Kris,
Make sure that your machine bypasses back to your tanks. This will increase the life of everything.
Have an inline filter to filter wahtever nasties might be present.
Carry extra parts, and learn what they are used for. Learn the theory of pressure washers so that you can perform quick fixes in the field when you need to.
Get a Large water line from your tank as close as possible to your pump, and use a 3/4" line from the trailer. For instance, I run a 2" line along the floor of my trailer to just under my pump and then a 3/4" line up to my pump. It is easier to suck water from a short 3/4" line than from a long one.
Remember that it is hard work.
remember that the hardest part is the sales.
If you notice that all of the contractors in your area are charging more than you, it is not necessarily because they are cheating the people, it is probably because they realize that is what it takes to stay in business and be profitable.
There will always be someone that will charge less, but not necessarily able to do it cheaper.
The cheapest parts are not necessarily the best parts.
Not everyone that posts onthese boards is an expert. A few know a lot, and some that want to be experts were asking the same questions you were 6 months ago. Learn who you can trust.
Take a trip to Danville and see David. You will learn a lot., just do not try to get equipment like his yet, it will break you on a new startup.
Always carry extra fuel and filters for everything.
There are more, but this is a start.
Scott Stone