It sounds like it may be from a broken throttle cable, or maybe it's bound up somewhere. Make sure it's one piece and connected on both ends and free in the middle
There could be many reasons why your Sears riding lawn mower won' shut off. The key could be jammed for example.
your electric motor(I assume) probably wont have enough torque, That is on a Riding type mower, not a push mower, it might work on a push mower as long as its not self prepelled, because your motor probably still wont have enough torque!
Perhaps it is the starter drive. That happened to my riding mower. Got the drive replaced, works fine.
because it needs a 1600 vee dub engine in it to make it go faster to have lawn mower races
Your flywheel key might be sheared
Pins on the brake disk on transaxle are rusty and stuck.
Without knowing what engine or what kind of mower it is this is just a guess. But, it is possible that your flywheel and/or coil have gotten rusty and are not getting the conact that they need to make the spark. Try removing the cover and sanding the flywheel and coil. If it is a riding mower with a key switch there are many possibilities including anything from a bad switch to one of the safety switches.
It sounds like a vacuum leak allowing air to enter the engine after the choke. The carb could also be dirty and not allowing enough fuel through it for the amount of air you are supping.
Mine is doing the same. It is still under warranty, but they will not honor the warranty, so I do not know what else to do.
There are way too many reasons for a mower not to run. Without more information it is impossible to diagnose the problem. If you still want help try asking again with the make of mower, the engine, details of what you have done and what the symptoms are.
replace battery & starter solenoid.. possibly carb.
replace it