Small Engines (Lawn Mowers, etc.): Sears Tecumseh Lawn Mower Engine., feeler guage, starter rope

Question
Got a  Older Sears Tecumseh 6HP L head engine mower that has set up a long time. I have put a good matching carb on it with fresh gas and new plug. Very Hard to get it  start and runs real rough and backfires thru exhaust and seems to want to run wide open. Reading Tecumseh manual, it mentions adjusting valve lash, says it needs to be between .004 and .008 with both Valves closed on compression stroke.Manual does not say how the adjustment is done or how you check the lash.I assume I have to take off valve cover and use feeler gauge. Any Ideas of how valve adjustment is done? Is there a way to check for a worn cam or do these engines have lifters? Valves are opening and closing but Engine does not sound right when you pull starter rope.Valves do not appear burned, but I am not expert.

Answer
Al to set the valves on that engine you first must remove the head. Next you set the piston at top dead center. This is when the piston is at the top right after the intake valve closes. Next remove the valve cover and try to insert your feeler guage inbetween the valve stem and the tappet. If it does not fit you will have to remove the valve and grind the stem of it till you get the proper clearance. There are special tools for this you may need to get. GOOD LUCK