Firing up the Smoky Briggs 18HP in My 1980s Murray GT Garden Tractor

Does this motor has some problems or what! All in all I really do think a valve is getting stuck open and causing issues. Seeing how the smoke buffs out the Briggs and Stratton's exhaust I would say a valve is not happy, or at least wasn't happy. According to the previous owner I do know this garden tractor had not ran is supposedly 4 years. While that is nothing compared to the GT6000s I think 15 years It sure looks like it has sat longer but hey who knows. Let me know your thoughts on what is going on with the old Murray and what some remedies could be. Maybe it just needs a good heat cycle haha.

May The Lord Jesus Bless Ya!!!