6. CYLINDER HEAD/VALVES STRYKER 125/150 Apply engine oil to new O-rings and install Valve Guide Driver them to new valve guides. Then, drive in new valve guides. · Be careful not to damage the cylinder head mating surface. · Check for damage after driving in the new valve guides. · The new valve guides must have oversized O.D. Ream the new valve guides with a valve guide reamer. Valve Guide Reamer · Use cutting oil on the reamer during this operation. · Rotate the reamer clockwise and do not insert or remove it straight when it is stopped. Clean the cylinder head and remove any metal particles. Special Valve Guide Reamer Valve Guide VALVE SEAT INSPECTION & REFACING VALVE SEAT INSPECTION Remove carbon deposits from the combustion chamber and valves. Apply emery to each valve and valve seat contact face. Lap each valve using a hand lapper. Remove the valve and inspect the valve face. If the valve face is rough, worn unevenly, or contacts the seat improperly, the valve must be replac Lapper Cylinder Head 6-11