It sounds like the carb. has gummed up. You should be able to take the bowl from the bottom of the carb with a socket that matches up with it. Take carb cleaner and clean the bowl and use the red hose that comes with it and spray in all the holes and the jet. Use an air compressor and blow into the carb and hopefully you will clean it out. Also, when you take the bowl out, there should be a stream of gas that comes out, this is a good sign as gas is flowing into the carb. If it does, than it sounds like the carb is gummed up. If not, check the fuel line up to the tank and see if you can get it flowing. Then if everything checks out, reattach the bowl and try and fire it up. I do believe this series of pressure washers use tucumseh engines and there prime to getting carb problems and just need a good cleaning. If the carb cleaning works, consider draining the carb before storage, or use a gas stabilizer.
Hope this helps,
Dave
David
April 2008