I have an '06 FLHRI with 98" and GMR heads, these are exiting through a set of D & D Dualies (true duals) to a pair of Rush Mufflers with 1.75" baffles.

I have a strange sound that I suspected as an exhaust leak.
It sounds like a high pitched, fast paced chirp when the engine is above ~2200RPM and is more noticeable under acceleration.
On the highway, I don't hear/notice it unless I turn my head 90 degrees, so that 1 ear is pointing back, and it's very noticeable then.

To me, it's coming right out of the back of the muffler(s).

I called Rush (EPI) and their head tech said it sounded like an exhaust leak to him.
He said that Rush uses a thicker gauge steel and the muffler clamps should be overtightened by 5 to 10 ft.lbs. from the spec 60 ft.lbs., and that I should not reuse the HD Torca clamps, for they are one time use only.

I got 2 new clamps and tightened them to 70 ft.lbs., I still had the sound, so I tightened them some more, still no luck.

I pulled the baffles out, since they were fairly new then, the wrap looks like it was covering the area of small openings (there was only a few layers though) and the tape was holding.
Not sure what this should look like though.

Do you guys think I’m hunting this sound in the right area, or is it possible that a engine problem/sound could only show itself out the back of the muffler?

Any help or ideas would be much appreciated.

 

I had to slide the clampsforwardas far as I could to get them to compress the muffler inlets against the head pipes. If you can't see some of the slots in the muffler inlets behind the clamps, you'll never be able to tighten the clamps enough to get them to seal. The inlet diameteron my mufflers were a bit oversized as well, they were a pretty loose fit on the head pipes.

 

A lit candle works real well for seeing exhaust leaks. Just make sure you do it where there's no wind!

 

Thanks guys,

The clamps are right at the edge of the muffler pipe, and I used a Bic lighter to check for leaks at the muffler to head pipe connection.
The D & D Dualies are one piece from the cyclinder head to the muffler for each.

I had originally purchased the mufflers with 2" baffles, but got a pair of 1.75" because I felt the 2s were too loud.
So I found them, and used the fiberglas wrap from those 2" to add to what was there on 1.75".

A test ride found I still had the sound, once everything got fully heated up, but it was different in tone and volume, and after several more miles, I swear the sound was gone.[8D]

I'll put more miles on her tomorrow and see if this trend continues.