If sandy creek is open again I would go there. But, I think they closed down when Hubbard Creek got so low, or that was what I was told and I may be completey wrong, but those guys are awesome and their mechanic that always worked on my Yamaha was second to none. I don't know if their Possum Kingdom store is there or not you might check.
I would go to an authorized Yamaha service center thats been trained on the SHO. There have been multiple service bulletins put out on the engine depending on year that would be well worth getting taken care of by a prefered service crew even if you have to make a longer drive. Before I used Sandy Creek for my Yamaha I once drove over to Rockwall marine 6 hrs one way for an issue on a Mercury I had that two of the places you mentioned did not properly diagnose and or fix. One of them actually caused an additional problem. - Rockwall marine is top notch too.
Edited by balata9999 (05/25/16 09:06 PM)