After a bit of research online, I learned that the “exhaust” temperature should cycle between 120’ and 160’ (approximately). Using my barbecue thermometer with remote probe, I tested the exhaust air temp and found that my dryer was cycling between 60’ and 96’ - clearly not hot enough to make much progress. Further research indicated that the valve coils were the likely culprits. I decided to replace the igniter and flame sensor while I was in there. It took about an hour to complete the repair once the parts arrived. Rechecking the “exhaust” temps indicated that post-repair the temps cycled between 106’ and 176’. I think that will more effectively dry the clothes.