COMPRESSIONCylinder HeadSection 6COMPRESSIONCOMPRESSIONBriggs & Stratton does not publish any compressionpressures, as it is extremely difficult to obtain anaccurate reading without special equipment.It has been determined through extensive testing, asimple and accurate indication of compression can bemade as follows:Spin the flywheel counterclockwise (flywheel side)against the compression stroke, a sharp reboundindicates satisfactory compression. Slight or no reboundindicates poor compression.Loss of compression will usually be the result of thefollowing:1.The cylinder head gasket blown or leaking.2.Valves sticking or not seating properly.3.Piston rings not sealing, which would also cause theengine to consume an excessive amount of oil.Carbon deposits in the combustion chamber should beremoved every 100 to 300 hours of use (more oftenwhen run at a steady load), or whenever the cylinderhead is removed.Remove Cylinder Head and ShieldAlways note the position of the different cylinder headscrews so that they may be properly reassembled. If ascrew is used in the wrong position, it may be too shortand not engage enough threads. It may be too long andbottom on a fin, either breaking the fin, or leaving thecylinder head loose.CYLINDER HEAD TORQUE PROCEDUREAssemble the cylinder head with a new head gasket,cylinder head shield, screws and washers in their properplaces. (A graphite grease or part no. 93963 should beused on aluminum cylinder screws.)Do not use a sealer of any kind on gasket. Tighten thescrews down evenly by hand. Use a torque wrench andtighten head bolts in the sequence shown, Fig. 1, and tothe specified torque in Table 1.Do not turn one screw down completely before theothers, as it may cause a warped cylinder head.Fig. 1. Cylinder HeadsJUNE 19811
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