Small Engines (Lawn Mowers, etc.): old toro not running above an idle, throttle plate, lawn mower

Question
hi i purchased a used toro riding lawn mower.  it may still be the 11-32 rear engine but tags painted over.  but think the engine has been replaced.  the problem i am having with it is the lawn mower will drive around yard at bunny/lowest speed but not fast enough to cut grass. if i engage blade it stalls. when i increase gas to engine it stalls.  it will start again but only runs at lowest fuel setting. this  just started doing this after i did jump started it with my car and since charged battery.   i checked air filter etc and throttle is visibly working.  I am more of a break it the fix it girl but need help.   thank you so much for your assistance with this.
mj

Answer
Hi MJ,

Check to see that the carb's throttle plate is opening all the way at full throttle.  Next, if adjusting the carb's jet screws don't help, I would suspect a clogged carb.  You will need to remove the carb, disassemble it, clean all the small internal openings and blow it out with compressed air.   Probe each and every hole with a small wire.   A carb rebuild kit wouldn't hurt either.  

I don't think the problem is electrical, so the recent jump starting shouldn't be related.

Let me know what you find.
Michael