Small Engines (Lawn Mowers, etc.): Valves, hydraulic lifters, hydraulic lifter

Question
My mower began to develop a miss. I checked the spark plug and was not getting fire to the combustion chamber. I swapped sparked plugs and still no fire. I determined it must be the coil. I replaced the coil and got fire into the combusiton chamber, however, I still had a miss and the same side was not sending any heat to the exhaust. I pulled the valve cover off and found that the rocker arms had come off of the pushrods and spring. My first question is what may have caused this? My second question is how do you set the valves on this engine. I believe that this has hydraulic lifters. The Engine information is as follows: Family: SKH725U1G2RA, MODEL # CH25S, DISP 725, AND SERIAL # 3003309391. Sorry for the long explanation, but I am at a loss.

Answer
Hello Todd:

No Worries. The Better the Explanation the Better I can Assist you. This has Become a Common Problem with the OHV Engines. Even the Engines with Hydraulic Lifters/Tappets. Place a Small Amount of Blue Thread Lock on the Rocker Arm Retainer Bolt Threads. Tighten the Rocker Arm Retainer/Mounting Bolt and Allow it to Set for 1 Hour. The Hydraulic Lifter does the Rest. You can View a Breakdown/IPL of this Engine at this Site Addy, http://www.smallenginepartswarehouse.com/parts.asp and Select the Shop Online Parts Look Up. Then Select the Model Tab. Then Select the OEM and Enter the Model and Spec Numbers (CH25S-?????). Then Double Click on the Model in the Results Area. Now you can Select the Section of the Engine you Wish to View. If you Hit a Snag or this Does Not Correct the Problem,  I am Here if You Require More Assistance. Hope this Helps. Let me Know What Happens, Please. May the All Mighty Bless You and Yours. Thanks.

Good Luck

Respectfully

John

PS: I am Allowed to Answer 10 Questions a Day. If you See I am Maxxed Out, then Try Submitting your Question at or Just After 8pm EST (US). My New Day Starts then. Thanks.

Respectfully

John