Sometimes it helps to slide the entire chain tensioner assembly rearward (closer to the rear sprocket) often times this will take care of minor chain tension issues without the need for
messing with the links.....since the stays typically taper towards the rear axle, sometimes I the brackets may need minor "adjusting"....Helps to have a large pipe wrech, vise, and/or large hammer....just be careful if you have to "tweak" things.

Andrew