Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Welcome to JUST ANSWER small engines, let me try to help you !! I don't know it all, but maybe together we can get you a satisfactory answer!
Most pressure problems with pressure washers is the unloader/spill valve. Locate it in your parts list, and revmoe it and clean and lube it. Then re-install and test.
I see question is still open, did you find problem?