It runs a little rich because of your elevation.
Less air, same fuel.
I'd start initial at 14 and try a couple more or more degrees to find what it likes. Remember you need to start the burn way earlier with less air/rich mixture.
You might find some gains by adjusting your APT.
Info here on that.
http://www.crankshaftcoalition.com/w...4MV_carburetor