The exhaust on my 1450 used to be real bad. Just pulling it in or out of the garage would stink up the garage and breezeway. Sometimes for a few hrs if the windows were shut during the winter. A sticking exhaust valve forced me to clean the head and valves to resolve. The bonus to the job was the exhaust stunk waaaay less. I no longer get asked if the cat is safe in the breezeway with all the fumes.
Bill