Troy Bilt Pushmower wont' start/backfires

Troy Bilt Model 860, High Wheel Rear Wheel Self Propelled, Briggs and straton engine, alright this is really buggin me to get workin with grass starting to show up, but last year hit a stump hard enough to shut mower off, since then mower would puff as it run, lost the first pull start after that, sometimes 2 or 3 good hard long pulls, so by the end of last year it wouldn't start at all no matter how many pulls. Since last week i have taken off valave cover and noticed that the gasket has tore so i have one on order, and i had no spark, cleaned the armature (badly rusted) with sandpaper set to .010 gap and put all back together, now when i pull i get a loud backfire and sometimes a shot of fire outta the exhaust, but still wont run. So im tryin to figure what part to by to fix and/or should i just buy a new one. The mower is 2 years old but for the first year I did some weekend lawn jobs. I just am really impressed with this mower and would recoment to anyone and want to fix it, myself

 

I'm betting you have sheared the flywheel key,, Pull the flywheel off & let us know what it looks like... If it's not in 1 piece,, it may be the problem... Roger

 

"hit a stump hard enough to shut mower off"
That is hard enough to break the flywheel key, which throws the timing off. I bet it tries to yank the pull handle out of your hand when you try to start it.

 

I will get a puller tommorow and look at the flywheel key, and as im looking at parts the gasket i was calling a valve is actually the head gasket that is tore, im assuming thats the puffing sound i was getting after the stump incident when it ran. thanks for the quick feedback

 

flywheel key was sheared in half

? though you guys refered to the stump incident as the cause for that, i prob run the mower a few times after that, was it catching (or binding) together long enough to start before or when it breaks the mower doesnt run at all

ddnt get a puller, used a prybar and rotated a while, still worked though, longer to get off than with a puller, when getting back to the lawnmower today, i did notice something else, inside the head as the piston is back i have oil, also in the side shafts, (exhaust?) where the rods go thru threre was a little oil also, it wasnt a pool of oil, just a little line in the bottom, is that normal, so now i got on order, head gasket and flywheel key, im learning about these small engines, still got me beat right now