I put a set of new rush 2 1/2" slip ons on my bike last night and those things have whistle to them. Have any of yall experienced this? I don't think I have any air leaks, it seems to me that maybe it's blowing a little air between the baffle and the barrel of the muffler maybe?

 

It's always been my experience that a exhaust whistle is actually a air leak before the muffler. My 06 Heritage done it when it was new with the stock exhaust. I narrowed it down to the cross over pipe leaking. These crossovers are not clamped they are just pressed into the gasket with hopes that they seal. Another Harley Engineer trying to save a buck.

 

Some time back, someone on here said they removed their baffles, knocked down all the high or pointy parts and it cured the whistleing in the pipes. Don't know if it works, but one of these days I'm gonna try it if I think about it before I ride instead of after. When I go over a bridge, it sounds like an old VW bug whistle.