I have one of these, and I winterize it usually by running the engine till all the gas is gone and changing the oil. Also, I drain the water from the lines and then store into my basement.
When I recently tried to use it, there was some lag whenever i pressed the trigger. Sometimes, water would blast out, sometimes not. I had to remove the nozzle and reinsert the nozzle and it works again, but then when I stop blasting and try to start again, it sometimes stalls. I don't think it's pump related, as there's water coming out of the gun with the nozzle removed. I can hear the engine go whenever I press the trigger.
Do you guys store your nozzles in mineral oil to prevent corrosion during the offseason? Any ideas?
I would try soaking the nozzle and blowing it good with air. Maybe even run a torch cleaner throuh it, but I doubt that would be needed. I have an old carpet extractor I had to clean the nozzles and some fittings with. The fitting was the one the hose attached to on the machine. Be sure to check any and all screens. Maybe a screen is clogging up with rust or hard water deposits. I have an old Karcher that did that. The pump was going out. When you winterize it, what do you put in the pump? How cold does it get in the basement? These things are relatively new to me, but from what I understand, it is easy to burn some of the pumps out by running them while not using the spray and allowing a cool stream of water through the pump. An unloader is supposed to help with this by dumping water when the pump starts to overheat. I bought a new one and need to learn more about that. Like how long can I can let it run without running water through the wand. Pumps heat up fast!