Unlike timing BELTS used in other engine designs, CHAIN systems as used on Suzuki engines are designed to run maintenance free. Having said that, they do not require replacement when properly maintained for the "life" of the engine. Under normal driving conditions and with proper attention to oil change maintenance periodicity, they will last for many for many years / miles. I've got 216K on mine thus far, with no problems.
When they DO fail, it's
typically precluded by a degradation in the form of noise (clickidy clack / tap) and poor engine performance, as opposed to a sudden "snap" and dead engine situtation, from what I gather.
Hope this helps.
