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I usually lurk in the back ground and read the forums to learn new things. I am a retired auto mechanic with very little experience with small engines. I came across a self propelled Snapper Hi Vac mower with a 5 hp briggs motor. The guy said that he couldn't get it to start and he wanted $30. for it, I bought it for 20 thinking that it was going to be an old gas, dirty carb problem. When I got it home I tried starting but it was a no go. I checked for spark first , it was a good and had a new plug in it and the oil had just been changed out, while the plug was out I wanted to check compression then I remembered I loaned my gauge set out several months back and it had not been returned yet, I covered the plug hole with my thumb , there was compression but no idea how much. I removed the air cleaner and gave the carb a shot of cleaner , it didn't even try to start. I kept trying for a while but I figured there must be something else. I checked the fly wheel key, it was in place as it should be. I removed the side cover to see the valves and they were moving. I removed the cylinder head, the cylinder is in good shape , smooth and no scarring, both valves open about 1/4 inch. I have photos of the head and block, does anybody have an idea? I'm only out twenty bucks if I don't get it going so it's no big deal. Thanks for this and all the things that I have learned while lurking.

Being a 92 model engine. If you open one of the valve and have one closed can you turn the closed valve with your fingers. I normally would put my thumb on them and try to rotate If it rotates then it isn't sealing and will need the clearances reset. The Briggs flathead or L head engines are known to float the valves over time. Normally the intake valve is the culprit.

ILENGINE said:

Being a 92 model engine. If you open one of the valve and have one closed can you turn the closed valve with your fingers. I normally would put my thumb on them and try to rotate If it rotates then it isn't sealing and will need the clearances reset. The Briggs flathead or L head engines are known to float the valves over time. Normally the intake valve is the culprit.

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I just went and tried, the closed valve is tight , I rechecked several times

Is the dead man lever pushing open and releasing the brake that rubs on the outer edge of the flywheel?

Pull the small black wire or kill wire off the ignition coil. Should empty the tank out IF the ignition coil is good.

You need air, fuel, spark and compression. See which you are lacking.

Need to lap that head and block gasket area prior to putting a head gasket on. Just did this on an L-head. Head was not flat. They never are. Take some 100 grit paper and a garage window. Thicker the glass the better.