Does it stink at all rpm or is it primarily an idle situation? What about a plug reading, have you run at cruise speed for five or 10 miles and done a plug check? You push in the clutch, or shift to neutral, and shut the engine off, pull over to the side and pull a plug. If it's black with soot at cruise as well as idle you've got too much fuel or too little air in the idle, transition and cruise circuits.

Sounds like the float may be set too high or the needle is letting some gas bleed by the seat.
The 1411 has an electric choke I believe, could that be your problem?

I would think being at that altitude you would want stage three lean which would be 1430 main jet,1453 metering rod and 1427 secondary.
Just sitting at idle and the engine speed climbs all by itself is a bit strange. Bleeding in fuel from somewhere or the butterflies are opening by themselves? Do you have a good return spring on the throttle?

I did a lot of adjusting on my 1412 To get the fuel air ratio where I wanted it. I left it a bit rich as that gave me more power, but didn't stink like you describe. Mine is 463 CI and it idles at 500 rpm. I do know they are altitude sensitive, going from sea level then over the Rockies to Calgary, my fuel air ratio changed all the way up and all the way down. Ran cleaner at Calgary's 3,532 feet than here on the island.

They are highly and easily adjustable and you should be able to get yours tuned in just make sure there isn't something besides the tune that is causing your problems, such as choke, float level rigging etc.