A single cylinder engine is impossible to balance so they use a balancer to offset the power stroke. This is to smooth out the engine vibration. It has to be timed according to the marks on the crank gear and balancer. The timing chain only keeps the Cam in time with the Crank so if you did not pull the entire side cover you most likely did not effect the balancer timing.
2006 Yamaha Bruin 350 Balance Gear
in Yamaha ATV Forum
Posted
A single cylinder engine is impossible to balance so they use a balancer to offset the power stroke. This is to smooth out the engine vibration. It has to be timed according to the marks on the crank gear and balancer. The timing chain only keeps the Cam in time with the Crank so if you did not pull the entire side cover you most likely did not effect the balancer timing.