I have noticed riding my Ultra Limited, that when I accelerate normally from a stop I can hear the air being sucked into the air cleaner, and the best way I can describe it is that it makes the engine sound like it doesn't have any power.

However, this weekend, I demo'ed a Road Glide and I did not hear that same sound. When I accelerated, I could not hear any air being sucked into air cleaner. The engine sound was quieter and seemed like it had a more powerful tone to it.

Any idea what would cause this?

 

The Road glide didn't have lowers so you can't hear it as well.

 

Try a CVO bike with lowers and you will really hear the air intake due to the open element air cleaner.

 

When I rented a limited for a day, I noticed that right away too. Seemed to have plenty of power, though.

Actually, I could barely even hear the exhaust over the intake noise.

Put in ear plugs - problem solved!