Symptoms of a stuck Valve??

[ericandrews331@msn.com]

Fe 350. Today after roughly running 20 mins across the job sit my carryall shut (under acceleration) off like you turned the key off. Well after a few minutes of trying to restart I hit the choke and it started, had to feather the choke and the pedal but at least it was moving got to flat open and straight ground and was able to manipulate the 2 and got up to speed but after a little bit started blowing oil smoke, let off the choke smoke stopped so did the cart, restart with the choke/pedal move a 1000 ft at speed more start to smoke let off the choke, smoke stops cart starts to die choke on and we running again. Long story short I get to the point where I am close to my guys and suddenly despite my rhythm cart begins to die I immediately let off the choke and the cart runs like normal for the next 10mins (no choke no smoke) then it starts the same thing again.
Any idea's people