thebruce wrote: ↑Thu May 28, 2020 10:32 pm
Just don't use substandard parts...
I second that: you stand the risk of throwing the baby out with the bath water.
I swapped a water pump out for new when doing the cam belt on a previous car, as the original water pump had 170,000 miles on it, and was weeping just a little. After putting the whole thing back together, the new 3rd-party replacement turned out to weep more than the original, even after bedding in!
If the idlers are spinning smooth as butter, with no slop, I personally wouldn't touch them (if it ain't broke, don't fix it), but hey it's not my bike! If you do swap them, then I'd go for top quality replacements, and keep hold of the ones you take off.
I'm aware these are expensive items though, and there are places that offer rebuilds, where they take your old ones, and re-use the backing plates to build new ones.
Let us know what you end up deciding to do.