What's the model of the mower? I'd start with looking at the teeth on the wheel and the pinion gear on the driveshaft that drives the wheels. Depending on your model, there may be a spring and woodruff key in the driveshaft under the pinion (make sure not to loose these). Remove the belt cover and see if the belt is engaging. If the belt looks worn, replace it. Check the driveshaft output bearings on the inside wall of the deck. If they appear to be in bad shape, replace them as well. I recently replaced the entire transmission assembly and drive shaft output bearings on my Toro recycler. Was pretty easy and you need snap ring pliers. Runs like new now.

Compression is the secret of the internal combustion engine. The fuel/air mixture in the cylinder must be compressed to be powerful when ignited. Compression occurs when the piston rises against the closed intake and exhaust valves. It's measured in psi and every engine has a normal range in it's specs that can be measured. The problem with measuring it on lawn mower engines is they all have a compression release mechanism for easier pulling of the starter cord which obviously would give a false, lower reading. I actually don't know how the mechanics get around this to find the true compression. Anyway, engines can lose compression from wear and faulty valve timing. Usually a lawn mower engine with low compression would indicate a new mower needed, but in a few cases low compression can be caused by hard carbon in the piston rings which doesn't allow them to expand and seal the cylinder. There are several brands of solvents for internal engine cleaning. The best in my opinion is 'KREEN' by Kano Labs, the makers of 'KROIL', a well-liked penetrant. I would use 'KREEN' as-directed in any engine I suspected of low compression. If it doesn't help, repair/replacement is indicated, because lawn mowers are basically cheap, and you can't justify spending hundreds on engine repair or replacement. The exception would be if you had a premium mower with a good deck and drive system that you really like. An aluminum-deck Super Recycler could be in this category - it all depends on how much you want to spend on it. I think your mower should have lasted longer. Cutting only a tad over one tenth acre every other time would constitute light use in my book, and most any mower should last almost indefinitely under those conditions WITH THE PROPER CARE. However, you can't overlook the possibility of a bad engine from the factory that may have a problem that just took some time to show up.

I've had similar experiences with my Personal Pace movers. Sudden loss of self propelling has always been caused by the self propel cable breaking. I would suggest removing spark plug wire, tip mower on its side ( oil spout nearest ground ) have someone push down on the handle (all the way down) as if you were mowing and look at the belt. It should be very taught around both pulleys.If not then your cable may be broken or loose. Replace it if its broken - adjust it if it's loose. If it is taught you may have a gear box or other problem. Just a thought. Hope this helps.

This Toro spec comes with a Toro supplied trickle charger you plug into home current. There is NO ALTERNATOR supplied on the engine. If the starter is NOT ENGAGING the flywheel (at all), it's not receiving 12V from the battery...most likely. Try charging the battery and try starting again....if the battery fails to charge, might be time for a NEW battery. If you feel the battery is "DEFECTIVE", see a Toro Dealer and "plead your case". T-Man