" The motor shakes a bit as if it is misfiring (if it had more than one cyliner - does it?). " You need to furnish more information such as the model number of the engine to start with since there are more than one 17 hp OHV B&S engine. Walt Conner

Well everyone... I went back to the basics. Something was telling me that this is not a carb/fuel issue. Why even after removing the linkages and manually "throttling" the carb and applying a little choke there seemed to be no differance. So I decided to pull off the valve cover and take a deeper look; I removed rocker arms and studs, the push rod guide, and began a very slow rotation of the fly wheel. Each time the intake valve would open, then close, just a few millimeters, I noticed a very slight movement in the intake valve (it would actually open a little then close again) then a millimeter more there would be a loud metallic click. I had not noticed this before. I would then place my thumb on the intake pushrod and rotate the flywheel and get the same results. This is when I knew there was an internal issue... either the tappet was sticking or a deeper issue with the cam. I removed the engine and removed the engine sump. At the bottom even though I have changed the oil, there was this silvery slug at the bottom (I used almost a gallon of engine cleaner to get the slug out), I knew this was not right. I aligned the timing dots and very carefully removed the cam shaft. And yes to my surprise, both cam lobs were very scared and worn down. So I'm thinking I'll have to replace the entire camshaft, tappets, pushrods, and sump gasket. Plus a really good cleaning... Any other suggestions? Thank you in advance for all your help, Ron

These engines are all physically the same size. The alternator MAY be different however, they will interchange although I am not sure you want to messing with an engine that is in warranty. Crankshaft and mounting holes are the same. You can go here and check out the internals of your old engine and any prospective engine. http://www.outdoordistributors.com/Briggs_And_Stratton/briggs_part_lists.html Walt Conner

Oil under valve cover is normal and vital to the health of the rockers and valves components. In this engine, the oil is thrown/slung from the camshaft, into the valve compartment, some oil also migrates along the pushrods in vertical crankshaft engines. The oil inside the air filter is mainly due (in your case) to the blown head gasket pressurizing the crankcase, forcing a lot of oil mist to be vented along with the pressure through the crankcase breather tube and into the engine to be burned. That is how/why a blown head gasket causes the engine to consume oil and blow smoke out the exhaust. It does not suck oil into the combustion chamber through the blown spot, it is the pressure escaping from the cylinder and into the crankcase that carries the oil mist out the crankcase breather and into the engine intake system that transports all the oil to the "furnace".