He used to drop into my chambers once in a while to smoke, and was first-rate company. When I gave a dinner there was generally a cover laid for him. I liked the man for his own sake, and even had he promised to turn out a celebrity it would have had no weight with me.
The owners manual on every vehicle should state how often the manufacturer recommends that you tune up cars, but as a general rule it is every two years or 30,000 miles, whichever comes first. Driving under extreme temperature and weather conditions will make parts wear out faster, however.
A tune up on a bike is a lot like an OIL Change in a car...it needs to be done after a certain amount of mileage, but should always be considered every 6 months or so on a bike that is used and needs to be considered safe and reliable.