Hi,
I have had your frustration.
Assuming you have pulled a sparkplug, touched the electrode to something metal like an exhaust stud or engine block, and have seen a spark as you turned the motor over, I would suggest your motor is flooded with gas and or water. To fix this, you can pull all the plugs, shine them up, dry them off, re gap them, and if you can, blow compressed air into the open cylinders to flush out any other crap. Put it all back together, depress the gas pedal once to the floor, keep it at about 25% throttle, and then try to start it. This exactly worked for me today on a similar problem.
If you have not seen a spark, I would suggest your pressure washer dislodged/broke the contact of one of the little wires that goes to your coil. Could be any of the little wires that go to the plus or minus side. Trace where they go and see if there any any connection you can tighten or fix.
I hope this helps.