Yesterday I swung by the recycling center and there was a complete 5hp Coleman pressure washer sitting in the metals bin. I wrestled it out and into the back of my car, took it home, and cancel all plans for the rest of the day.
I filled the tank half full with gas and tried to start it. No gas getting to plug. Pulled and dis- assembled the carb - looked fine. I put my hand over the intake port and cranked - pressure coming out during compression stroke.
Pulled off the head, everything looks good, pulled off valve spring cover - ahh haa, no clearance on intake valve, keeper on exhaust valve is off.
First the intake valve, take it out and grind down the stem tip until I have about 15 thou clearance, put it back on.
Now the exhaust. I take the valve out and the stem look terrible. It's necked down nearly 1/8" where it rubs against the guide and the shoulder where the keeper lives is all chewed up.
I grind the worn areas down to clean metal, fire up the oxy-ace torch and blob braze over it. I chuck it in the lathe and do my best to true it up. Nothing I'd be proud to show to a real machinist, but better than before. I grind about .015 off the tip of the stem, like the intake valve so I have some clearance. I put the valve back in and button up the valve spring cover.
I make a new head gasket from gasket material, spray both sides with copper permatex, torque it to 25 ft/lbs and put the rest of the engine back together.
Now we have some compression. With just a little bit of tweeking around, it starts and runs great. I hook up the water, fiddle with the nozzle and I have a working pressure washer. I pressure-wash the pressure washer.
What I learned:
Gas engines really want to run.
I get unbelievably compulsed to fix things, especially free things.
What I'd like to know:
Where did the valve clearance go?