Cylinder head removal is not always necessary to replace broken valve springs and or defective valve stem seals as these jobs usually require the use of only two tools and compressed air. In absence of compressed air one can use a length of nylon rope so that the valves do not fall into the cylinder. Start with the elimination of the valve cover of the cylinder head in question and, if all valve stem seals are to be changed, both covers should be removed. Second, take off the spark plug of the cylinder containing the faulty component and if replacing all seals thus take off all spark plugs. Operate the crankshaft in a circular manner until the piston in the damaged cylinder is aligned at the top dead center on the compression stroke; do this cylinder by cylinder starting with cylinder one in the firing order sequence 1-4-2-5-3-6. Insert a spark plug thread an adapter into the spark plug hole and attach an air hose to it from a compressed air. If compressed air is not available, place the piston just prior to top dead center of the compression stroke and insert a long length of nylon string through the spark plug hole and into the combustion chamber until all of but one end of the string is pulled out for removal. Jam the shop rag into the cylinder head holes so that parts do not go into the engine, and using valve spring compressor, compress the spring/damper, then remove the keepers with the tips of a needle-nose plier or magnet. Pull off the spring retainer or rotator, the sleeve, the valve spring and the guide seal. If air pressure is not sufficient to close the valve it will cause valve face or the seat to wear and to address this; you will have to remove the cylinder head. Put a rubber band or tape around the upper part of the valve stem so it does not fall into the combustion chamber and then deflate the tire. Check for such things as on the valve stem that the head should not bind in the guide; if it does, the head will require removal to be fixed. Put the air pressure back on to lock the valve shut, then take out the tape or rubber band. Use a drop of engine oil on the valve stem and fit a new rubber suction cup to the stem; put the spring arrangement in place on the stem of the valve on another side. Screw in the valve spring retainer or rotator, squeeze the spring and put the keepers in the grooves, using the grease to maintain position if required. Withdraw the rope, if any used, and turn off the air hose and detach the adapter inserted into the spark plug hole. Last, fit the rocker arm(s) and the push rod(s), the spark plug(s) & wire(s) and the valve cover(s) tighten and start the engine look out for oil leakage and some unusual sound emanating from the valve cover part.
