RE: Welcome to Club SAITO !
I know that my Saito FA-82 spins a 14x6 prop at around 10000+ rpms. So, your 1.00 should spin the 14x8 prop a lot better than 9000 rpm, IMHO. Did you check that all the bolts are tight? How about the valve gaps? I am not sure the repair center would necessarily adjust those unless specifically paid for it.
If you have a test bench, I would set on the bench and run it/adjust it. That would give you easier access to the engine for tuning/checking, and also eliminate the possibility that the problem is in the plane fuel system.