You ask we answer. Here's the latest in our "Ask a Mechanic" series.

Q: How often should I change my coolant?

A: Whether you ride a dirt bike or ATV, the easy answer is check your owner's manual for the recommended service intervals on changing the coolant. But, since you're probably like most riders you lost track or forgot to keep track and don't remember the last time you flushed the radiator, at least in terms of hours.

It's easy to forget the coolant because it doesn't need changing often. Unlike the frequent oil change which is relatively inexpensive and a pretty easy job you probably remember the last time you changed the oil and filter because it was likely last week. But even if you did forget or lose track of service intervals for the oil change the best thing is to go ahead and change it again. It takes about 15 minutes, if that.

Once a Year

Changing the coolant in a dirt bike or ATV is a bit more complicated and you don't need to change it that often. Besides, running old coolant is hardly equivalent to running old oil. However, a good rule of thumb is to change the coolant once a year for average riding. If you ride every weekend whether racing on the track or trail you probably want to step that up to every six months. Of course, if coolant ever boils over change it immediately.

One trick to remembering, if you lose track of the service interval hours, is to change the coolant when performing other routine but infrequent maintenance needs like a top-end. So every time you perform a top-end, flush the radiator at the same time.