have a 16hp vanguard gdlt that the electric start will crank it right up but when i turn the key off the motor keeps running..any advice on whats goin on?

I have the same problem.. but I know what is causing mine. if you follow your kill switch wire up to the engine, is there a little black wire that runs from where it is mounted to your starter? if not, that is why it isnt turning off.. hope this helps.