Call me crazy but I no longer go by the spec in the service manual. On my FXDL, when set it to the factory spec of 1/4" @ 10 psi, it is way to tight in my opinion. I have never seen in my life ANY belt be as tight as the spec on my bike. To me it is unnecessary and causes too many side effect problems.
I no longer run the spec the service manual calls for. It made a huge difference in the way the bike feels & rides. Time will tell if I am wrong. One thing for sure,,, I will admit it.