Post by roger on Nov 23, 2023 13:14:37 GMT -5
The pictures show balancer chains (top) compared against starter chains (bottom). Although pitch etc. seems to be identical at first glance, the major difference (other than the number of links) lies in the pin thickness. The pins of the balancer chain are at least 10% smaller in diameter than those of the starter chain. Which means that their cross section is about 20% smaller for shear strength. Smaller pin diameter yields less load bearing surface, resulting in accelerated surface wear which is the source of slack. Why Yamaha would go this route with a part vital to engine survival, beats me.
