Hi Danny,
Is this a problem that became evident only in the last few days? I ask because I got the impression from the other thread that all was well in your RetroAir world. Regrets if things went south on you (is that expression used in the Southern Hemisphere?).
I think you’re on the way to either proving or disproving that it is possible to run the RetroAir kit with two idlers and a single belt. Please let us all know if the ax50 belt works (that’s still a single-sided v-belt, right?), or if you try a double-sided v-belt as @64etype suggested in this post.
If you can’t get any single belt to work on 2 idlers, I can tell you more about my 2-belt setup with the caveats that it is designed for a 3.8 engine, has no idler, and hasn’t operated yet.
Best of luck.
Bob