Generac pressure washer keeps blowing pump head gaskets

Factual Questions
1

My Generac pressure washer keeps blowing out the pump head gasket. This is a stamped-out pattern in thick, stiff paper. I don’t see what is supposed to keep it in place - that is, it looks like it OUGHT to blow out. I can replace it and put a bit of gasket cement on it, and tighten the bolts till I think they’re almost ready to strip, but the gasket only lasts about a minute before it blows wide open and almost all the flow comes out there instead of the wand. Though, for the minute it lasts, everything seems to work right - pressure, engine loading down while pumping, flow starts and stops with wand trigger.

How in the world is this supposed to work?

The local repair shop helpfully asked why I don’t just discard the machine, which has about 5 hours on it. How many hundreds of dollars was it? The gasket costs about $2. Sheesh…

2

The head may not be flat. Assuming the two mating pieces are indeed true, overtightening of bolts can actually exacerbate the problem. Head bolts have a tightening sequence and torque value, and failure to observe both can distort the assembly and invite gasket failure. There should also be a pressure governor to limit build up when you’re not flowing. If that is mis set or malfunctioning, the cylinder may be exceeding design pressure for the gasket.