Front drive wheels won't engage

HI DAVE, have you by any chance got the mowers cable stuck on the choke. It sounds as if too much fuel is getting through.

check for a spring loaded idler pulley that keeps tension on the belt out of place.

Replace drive cable

I have a 22" Toro Recycler Lawn Mower with front wheel drive. After many years the original tires wore out, primarily the left front.
After I replaced the wheels the front wheels kept falling off. I learned that Toro uses an unusual two layer washer on the front wheels. You need a) either an exact replacement for this washer OR b) two separate washers. The hole of the washer is 3/8" Everbilt has the smaller flat washer PN 637-009 and the larger washer can be found in the Everbilt PN 281-293. The SMALLER washer must be placed closer to the frame, the larger washer is closer to the wheel. Once this was done it ran perfectly.
Later I found pieces of the original washers in the grass. Toro had the replacement washer available on their website, I was just in a hurry to get the mower back up and running. The Everbilt washers were purchased at Home Depot.

Got the same problem with mine, replaced the drive belt, removed the wheels and checked for rocks and pebbles, greased, checked also bottom of gearbox. grease was present no broken teeth, top pulley has excive side to side play. Have not disaasembled yet. Hope someone would have had a solution here.

There could be a tightening screw on the cable, or your cable is just stretched out you have to replace.

most likley it is the gear box has failed but first take one of the wheels of to make sure that the plastic teeth on the weels didnt go bad (unlikley but wishfull thinking)

On my Toro recycler, I also had the front drive stop working -- and fixed it after reading the solutions here.

First, the plastic cover on the top deck that goes over the front drive mechanism must be loosened enough to pull it up. Before you can do that, on the underside there is one screw to take out.

Once that's done, all you have to do is pry the plastic cover up enough to see the belt and pulley that make up the front drive assembly. On mine, the belt had simply come off the pulley. Putting the belt back on, then tightening things back up is all it took to put the Toro back in sel-propelled happiness. Good luck!