My old man's 15.5 kohler engine lawn tractor broke the belt and when he installed a new one it would not disengage even with the lever all the way down. It would instantly try to stall and make a loud screeching sound and eventually would cause smoke. I reinstalled the belt by adjusting the engagement lever and it will run now but after about 15 seconds begins smoking again. I am not sure if the cable is still to tight or the burn belt is sticking now that it is damaged. I will say that once I stop the engine the belt does seem to stick to the main pulley. I have to push the belt into the pulley all the way around to free it.

So the question is, once a belt is burnt is it going to stick or do I need to look for another problem like adjustment... the only way I see getting more slack is to tighten the bolts that run from the rear of the front wheel back to the mower deck. This would move the deck forward and should allot more slack but since I never took the time to look at her running right I have no idea how much slack this pull needs to slip around with the lever disengaged and spin the belt with it engaged.

Thanks in advance!

I don't think you have the right sized belt. If you can get one from the lawnmower manufacturer or go to a lawn mower repair store you can probably get the right belt. They probably tried to measure from the worn and stretched belt and got something "close." Belts for lawnmowers may use different materials in some cases.

If the belt has been burning then it should be replaced.

Don't know what model you have ,some of these craftsman took three diff.size belts.depending on which deck they had,and depending on if it was a electric or manual blade engagement.
Luck