My pressure washer keeps stalling mid-job - help!

Hey everyone, newbie here with my first pressure washer issue. I got a gas-powered 3000 PSI model last season, worked fine then. This spring, it starts up okay but after about 10 minutes of use it just stalls out completely. Won't restart until it cools down for like 20 mins. No weird noises or anything before it dies. Any ideas what's causing this? I'm pretty handy but pressure washers are new to me.

Gary, welcome! I mostly do woodworking but I've had similar issues with small engines on my tools. Sounds like it might be overheating. Have you checked the oil level? Also, make sure the cooling fins on the engine aren't clogged with debris - my neighbor's pressure washer did exactly what you're describing and it was just packed with leaves and grass clippings.

Larry's on the right track with overheating. Gary, couple things to check: 1) Is the pump getting enough water flow? A restricted inlet or clogged filter can cause the pump to overheat and trigger thermal shutdown. 2) Old gas? Did you use fuel stabilizer over winter? Bad gas can cause vapor lock when it gets hot. 3) Check the spark plug - if it's fouled it might fire when cold but fail when hot. Let us know what you find!

Seen this a hundred times on job sites. 90% chance it's the unloader valve sticking. When it stalls, does the engine sound like it's laboring right before it dies? The unloader regulates pressure back to the pump - if it's stuck, pressure builds up, engine works too hard, overheats and shuts down. Try running it without the spray wand attached (just let water flow through). If it doesn't stall, that's your culprit. Easy $20 fix usually.