OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Briggs and Stratton Missing on one Cylinder

The engine you have has a reputation for blowing the head gasket, usually from the combustion chamber into the pushrod recess. Escaping hot gasses passing into the pushrod cavity will pulse into the rocker cover as well as into the crankcase. Hence the symptom you describe is consistent with a blown head gasket, but it sounds as if it is rather badly blown for heating of the rocker cover to be noticeable.

It is quite undesirable to operate the engine with the gasket blown, because the hot gas will erode the cylinder head or the top of the cylinder block, and this is relatively difficult to fix.

To diagnose the fault all that is usually necessary is to establish that the compression pressure is lower on one cylinder than the other, but the tappet clearances are correct on the leaky cylinder. When you have verified this it is still possible it is a leaky valve or leaky piston rings rather than a gasket, and if it was, say, a side valve Briggs engine, it would be a good bet this is actually what has happened. However since the engine has a reputation for blowing head gaskets, and that is an easier problem to fix compared with either rings or valves, it would be usual practice to remove the cylinder head and inspect the gasket. I think most mechanics would replace the gasket and retest the engine even if they could not see leakage marks on the gasket, just because of the engine's reputation.

You have also said the engine had its short block replaced by a local repairer. In other words, the head gasket was fitted by a local repairer, while the rings and valves were fitted in the Briggs factory. I think statistics would show that repairers are rather more likely to make mistakes, than the North American Briggs factory production lines are.