I'm riding a Honda CM400C, which is an air-cooled bike. It's been pretty hot of late and I'm noticing, particularly riding in the city, that the bike runs a little rougher when it warms up. The spark plugs read fine, best I can tell, but it's clear that the character of the ride changes. What are the symptoms of overheating on an air-cooled engine? What strategies would one pursue to manage heat?