If you are asking about the oil for the gasoline engine then you can use a 30 weight engine oil like you would use in a car engine. Pressure washer pumps use a special non-detergent oil which is not the same as the engine uses.
Frank, either the unloader valve is out of adjustment(try loosening it off) or it is faulty and needs rebuilt or replaced as most people do.
Check the attached vids,instruction and guides, Good luck
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I would be happy to advise you further and give you more detailed answers then the others have. Guessing at an engine or unloader problem will not actually assist you in getting your pressure washer up and running again. The most important question is, what is your pressure washer model number? That is the first part of this process. Honda is just the manufacturer of the engine that you have. They don't build pressure washers. If you can provide the model number, you should be able to find this on the cart or frame of the unit, then I can determine what pump you actually have and assist you in determining the actual problem to get your pressure washer up and running again. There are a few issues that can cause this problem, all of which can probably be repaired with minimal cost. If you can provide me with more information I would happy to assist.
I have the same problem. The design is bad with the weight of the hose and the lelength of the plastic inlet tube from the body creates a sheer force that causes it to break. I cannot find anything but a plastic inlet part. If someone would create a metal inlet connector they could make a lot of money. You need a lot of hose slack when moving your power washer or it will break off the inlet and the parts are abotu $20. Very poor design!!
remove the pump and throw it away. Buy a better designed pump on eBay. just search your pressure washer model number or the obsolete rebuild kit part number a14292 you'll find the better pump.
Check the oil level, if it's very low or burnt then it may have siezed up internally.
It could also be that be that the cylinder is filled with oil or fuel.
if the washer was tipped over the fuel or oil may have migrated in to the piston combustion area.
Is the gas tank topped off? Is the water hose plugged into it and turned on? Is the gas valve open instead of closed? is the throttle turned on fully? Is the spark plug wire attached all the way? Should work after all of this.