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My 6.5 HP Briggs & Stratton is on a Husqvarna self-propelled lawn mower. I'd say it's probably 6-8 years old. After mowing for a while the other day, I killed the engine to get a drink. When I attempted to start the mower a while later, it would not start. It sounds lifeless when I pull the cord. I replaced the spark plug & cleaned the carb... anyway, I don't believe it's getting any spark. I have replaced the armature with no improvement. I have disconnected the small wire from the bottom of the armature(I believe that's what kills the engine), anyway nothing changed. Do you have any suggestions?

tcb7 said:

My 6.5 HP Briggs & Stratton is on a Husqvarna self-propelled lawn mower. I'd say it's probably 6-8 years old. After mowing for a while the other day, I killed the engine to get a drink. When I attempted to start the mower a while later, it would not start. It sounds lifeless when I pull the cord. I replaced the spark plug & cleaned the carb... anyway, I don't believe it's getting any spark. I have replaced the armature with no improvement. I have disconnected the small wire from the bottom of the armature(I believe that's what kills the engine), anyway nothing changed. Do you have any suggestions?

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I've got a couple of those engines on 2 of my mowers and have worked on a few besides. I'm curious as to what you meant when you said "It sounds lifeless when I pull the cord." Do you mean it didn't have much compression resistance when you tried to start it? And you replaced the armature as well you say. And pulled the kill wire. Unless you've got a bad spark plug ,coil/armature then it should fire up and run, and not stop w/o grounding the coil. I'm thinking the "lifeless" pull would indicate stuck intake valve not letting it get compression, even if it is firing the plug. Have you checked the plug when someone pulls the cord? Assuming you're getting spark , then I'd be looking at a stuck valve. What kind of compression are you getting?
You can take the valve cover plate off and check to see if the valves are moving freely. If not you could squirt some penetrating oil or carb cleaner around the holes going into the head and pull it over to see if that frees them up. Also check valve clearances while you're in there, in fact I'd check that first. Not enough clearance would keep the valve off its seat and kill compression. Carboned up valves and head and on the valve stems can cause binding and not let them seat. Hope this helps. Might have to pull the head and remove the valves and clean them and de-carbon the head and valves etc.

+1 what Dave said and I hope your piston is moving up and down. To me "lifeless" could also mean a blown rod if when you pull the rope and the engines spins with no resistance at all. I doubt it though.