I once owned a Karcher gas pressure washer, used it to prep cedar siding for stain twice. Gave me a lot of trouble. Not the engine, but the pump, the wand, the tips, and the hose. I was glad to be rid of it. Now I have a $129.00 Green Wonder from Lowes that is not powerful, but it is good enough for cleaning mold off concrete and it seems to run flawlessly.