Quieter/Smoother Under Load?
 

I have noticed a few times (more often now with my new commute) that after going up hills where the bike is under a larger "load", the bike becomes a bit muffled sounding but smoother. Less vibration and crisper even. The throttle response is sharp and it just PULLS. The D&D pipes are obnoxiously loud otherwise and have a very distinct popping sound to them. After this "change" they sound muffled and its less of a pop and more of a purr.

At first I thought maybe the elevation change just popped my ears hard enough to scatter my brains as it didn't quite make sense to me but its happened plenty of times now. Any ideas?

My best guess is a change in air density; the elevation change is roughly several-hundred feet, but I would not have thought that it could affect it that much.

I want to clarify I'm not talking about a change in pitch AS ITS UNDER LOAD. This noise change remains until I usually park it and she cools down. However, yesterday was the first time that after work she was still "quiet" and not D&D obnoxious. My wife even asked about it...

Too many variables to comment beyond...you might be overthinking it.:D

Best I've come up with is the carb is WELL out of tune. So the common theme seems to not really be the "under load" factor as much as its just a consistent RPM held for a length of time. Typically my commute has me riding at ~4.3k RPM for long stints and that's where I've been hearing the change. Just happened that in the past the only times I've ever held a consistent RPM for any length of time was where there were large inclines (I often drive near or in the Adirondacks).

Its just one of those things where if it feel's THAT good you keep chasing it. So since I doubt the previous owner ever tore it apart, I will do so this winter and give it a good rebuild. I'm hoping that doing so will solve my issue. If not, its likely needed anyways.