He got back to me and has decided to keep the engine. He said he has a lot of engines and this is the only one he has an issue with. Something may have come loose during shipping.
I did ship via the USPS and it took a long time to get to him even though it was a rather short distance and was mailed Priority Two day service.
One curious thing is he said operating using Bluetooth was flawless. I wonder why that worked so well.