Exhaust noise

[Rob S.]

I just got back from a short (10 mile) ride. I got her up to 95 near the end, when it was as warm as it was going to get (about 170 f indicated).

When I was turning into my block, things didn't sound right. I looked behind me to see if an old air-cooled VW was passing by. Wasn't.

When parked and idling at home, I determined that a new sound was coming out the tailpipe; not a pleasant sound to my ears.

This is my first bike with a fiberglass-wrapped baffle. When I bought it 27 months and 6,000 miles ago, PO told me it needed to be re-wrapped. I didn't do that - it made a beautiful sound. I'm hoping it just burned up some more fiberglass, but it doesn't seem much louder, just nasty. (And I rode my Z1 with a wide-open pipe for several years.)

When I started it tonight, it did something it never did before: it didn't go to 4,500 rpm and rising, necessitating backing off the choke. It went to a steady idle of no more than 3k on full choke.

What, if any, engine problems could a new exhaust note indicate? Could it be carb or intake related?

It sounds kind of like an exhaust leak, but only out the back. That's why I'm hoping it just lost a little glass, but it doesn't have that same beautiful in-line four sound I crave.

Thanks.

[tkent02]

I have had a chunk of crap from a muffler get loose, go further back in the muffler and plug up some passage. Changed the sound, once it made it run really poorly.

Once on an old car it did that and actually inflated the muffler like a balloon. That one didn't run well at all. Probably you will have to get in there and look.

[Sandy]

Supertrapp or conventional 4 into 1?

[Rob S.]

GS1100EZ V&H "Street Megaphone", APE pods

[Sandy]

GS1100EZ V&H "Street Megaphone", APE pods

Ok. On old Supertrapp's the inner baffling can deteriorate and the baffle debris along with bits of the fiberglass packing can plug the diffuser plates and cause some pretty weird problems and sounds.

[Who Dat?]

Pull the baffle, inspect what's left. If it's a typical baffle, the inner core goes straight through. The 'loudness' of the pipe is determined by the diameter of that inner core. Any fiberglass (or other) wrap that you put around the baffle just controls the echo in the outer chamber. If you want something that will last quite a while, order up the coarsest grade stainless steel wool that you can find and wrap away.