Just replaced Opti, is there s special way to put the balancer back on? I noticed an arrow on the balancer and a line on the flat peice on the crank it bolts too and I lined them up. My engine seems to have a slight vibration at idle.

 

Since the bolt holes are not an equal distant apart it can only go one way. Lining up the arrow on the damper with the mark on the hub just keeps you from searching for the correct alignment. You put it on correctly.