Mercury F1TZ-6571-D Valve Stem Seal

The first step is to remove the valve cover(s) and spark plug(s) from the affected cylinder.

The rocker arm(s), pushrod(s), spark plug(s), and valve cover(s) should be reinstalled.

It should be ensured that the piston is at Top Dead Center on the compression stroke.

If the valve stem binds, either the valve is bent or the guide is damaged, and the head will have to be removed for repair.

Install the spring assembly in position over the valve, then install the valve spring retainer or rotator. Compress the spring and position the keepers in the grooves, applying a small dab of grease to hold them in place if necessary. Remove the pressure from the spring tool and ensure the keepers are seated.

The steps involved in the repair process using the air method include valve cover removal, cylinder TDC positioning, applying compressed air or rope to retain valve position, using specialized tools to compress the spring and remove various components, replacing valve stem seals, and reassembling the components in reverse order.

Thread an adapter into the spark plug hole and connect an air hose from a compressed air source to it. Alternatively, a length of nylon rope can be used if compressed air isn't available.

If air pressure fails to hold the valve in the closed position, the valve face or seat is probably damaged, and the cylinder head will have to be removed for additional repair operations.

If the valve stem binds, either the valve is bent or the guide is damaged. In either case, the head will have to be removed for repair.

Use a valve spring compressor to compress the spring.