Case 430 stumbles and blows white smoke at high throttle.

Just had a problem pop up I'm hoping someone can help with. Machine was running fine, digging out a stump, nosed down at a steep angle and heard a very slight miss. I backed out to level ground and played with it some. At this point once you move the throttle above halfway or so the engine begins to miss and stumble and blow lots of white, acrid smoke out of the exhaust. It Idles fine and sometimes you can slowly sneak the throttle up and it will keep running correctly but usually it begins...

Case 430 stumbles and blows white smoke at high throttle.

Case 430 stumbles and blows white smoke at high throttle.