Just the other day I noticed a slight flapping/popping sound coming from one of my TBR slip-ons at idle. Listening closely I can hear what sounds like a loose baffle (or is it the packing material?) slapping harshly when I close the throttle (bikes too loud to hear it with the throttle open). I know TBR sells repacking kits, but, that's just the packing. I don't want to tear it open unless I have a better idea of what I'm in for. Anybody experienced this before? Should I start crying now?

 

Mr M
I once thought my TBRs (C4 high mount carbons) were also making some strange flapping sound. I bought a repack kit and after taking one can apart (not fun) I decided not to replace the packing since it looked fine. The stainless-wool around the inner tube on the carbons protected the glass packing from any wear-and-tear... I then experimented with inserting a piece of stiff wire screen into the inner tube (maybe 2" x 10") to see if it would change the exhaust sound note and it did make the things sound a bit better - so I left them in there..... Crazy perhaps, but it worked for me...

 

Stick a broomstick inside and wiggle it around. You'll answer your question.

 

In point of fact, the broomstick test answered no question. I grabbed a flashlight to see if anything was rattling while somebody revved the throttle for me. Still didn't see anything flapping or rattling.

The can is just an outer cylinder, packing material and the mesh screen, right? So what the hell is it? No amount of pushing, pulling or holding a stick against the screen changed the sound. I have my reservations about pulling the damn thing apart, so any other suggestions would be appreciated.

 

Actually, the broomstick test answered your question just fine. The idea is to see if the perf tube is loose. If the baffle was free, it would have been obvious.

I suppose I should have mentioned that you do this with the engine off. :-0

 

How about a loose rivet? Maybe a rattling spring. Any other mods to the bike such as a Comp Werkes Fender Eliminator?

 

Ah. I'll try it with the engine off today.



I've checked damn near EVERYTHING on the ***-end I could think of that would rattle. So far, no good. Maybe I'll call TBR.

 

Mr M
Are you sure the flapping 'sound' is just that, a sound wave that results from exhaust gas pressure/turbulances in one pipe?
If you can hear the flapping sound at idle use the broom stick down the pipe to just see if the change in internal exhaust gas flow changes the sound output and eliminates the weird flapping ....

By the way, where in LI are you located?

 

Are the two springs on both endcans? Is it possible that you are describing an air leak?

It's really hard to diagnose noises over the internet.

 

Well, today was shot. Too much other crap to do. I'll try to get to the bike after work at the shop tomorrow. At least to pull the can off and run it over with my dump truck.

I live in Nassau county. Glen Cove. Know the area?

 

Just to prove it can anything, I had the same thing happen on a newish 02 VFR with a stock exhaust. It was driving my friggin' crazy. Eventually, I dropped the entire exhaust (a PITA on a V4) to find that one of the weld supports in the catalytic converter had broken off and was vibrating in the cat con.

OK, I know the VTR doesn't have a cat but it just goes to show it can by anything harmonizing.

 

Yep, I was born in Glen Cove, grew up in Hicksville and have 4 brothers in Suffolk .....

 

I pulled the cans off in the shop today and swapped them to the opposite sides. It's DEFINITELY in the can. While it was off I shook, tapped on, tossed, ran over and pummeled it. Almost. I can detect nothing loose. I stuck a broom handle in the can (again) while it was running and the deflected exhaust had no effect on the sound.

I suspect it's a loose rivet and I'm probably going to have to suck it up and pull the damn thing apart.

When I pulled the cans I checked the seals and they were all good.

You ain't just whistling Dixie. I appreciate everyone's help!

Ha! Small world. If you're ever out this way you ought to give a hollar. It'd be nice to ride with (let alone see) another 'Hawk.

 

I think I may have duplicated your problem yesterday. Started up the bike and heard a ting-tinging noise from one can. It got faster with revs.

Turns out my three year old had dropped some pebbles into the can. Mine were small and flew out when I rev'd it higher. But a heavier contraband might not blow out, I suppose.

Could this be your problem?

PS. He promised never to do it again. ;-)

 

Ahh the wonders of parenting! Sure he promised he wouldn't do it again but he'll find something else to put them in. My son's favorite thing to put things in is my sub-woofer, talk about funky sounds. :wink: