Adjusting Valves For 11 HP Honda GX340 OHV

This small Honda engine runs a pressure washer. It's a rope start and I tried to start it after it had set up for about 4 months. It kicked-back so hard it felt like I had lost a finger. I removed the spark plug and with ignition switch off, I pulled the rope and it easily turned over. OK, so the compression relief for starting wasn't working. I removed the rocker cover and adjusted the valves to my owner's manual, ie., .015 intake .020 exhaust, cold. When observing the exhaust "bump" to relieve compression for easy start I noticed it was just a small bump. And still too much compression for rope start. I checked the pushrod to see if bent, it wasn't. So, on the exhaust valve lash I turned the rocker nut down to hand tight. Then with wrench I tightened the nut one full turn. Result was I had no compression. I then backed off the nut a quarter turn. Still no compression. I backed off the nut another quarter turn. I felt a small amount of compression. I backed off the nut another quarter turn. Now it starts on the first rope pull and runs like a fine watch.