I have 2 MX-2 cleaners (single gun hot water/steam). They have several interlocks and can be tricky to run. I have only run mine in the hot water mode (~225-250 degrees C), possibly got one to work in the steam mode once (~350 C). The pump is some kind of Cat pump similar to what is used in car washes. I once saw 500 C in the hot water mode as I was running away but the pressure relief did work that time. The main switch is made by Bremas (Italy) and can get real stiff. If you dowse it well with WD40, that should loosen it up. I believe on both of mine, I had to replace the transformer for the burner. It is a stock item for house furnaces burning heating oil. Most items are off the shelf. Like I said, the main switch may have been a custom item (seems like it is a 1602 or something in that ballpark). Make sure the hoses are not rotten since live steam will mess you up bad. Be sitting down if you price exact replacement hose. Someone on eBay sells a steam hose that is not crazy expensive, made by Goodyear I think. The fittings must be for steam. It degreases equipment pretty well but it is not a magic wand, you still need something like Greased Lightning or Purple Stuff to loosen up the grease/oil.
I bought a M17MCHF that is simpler for me to use. The worst problem is getting the burner to light. Mine was modified by the Navy to burn Diesel. When the burner finally lights, you can hide a house in the smoke cloud and it will roar because usually there is a surplus of fuel in the combustion chamber. I have run it over 30 hours now. I have great pictures on my iPad but am too stupid to shrink them down to fit since I always end up with a little section from the upper corner that doesn't show anything.
Robert