Arrow Slip-Ons excessive backfire and very bad sound

Iroh

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May 18, 2020
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Dubai
Hi Guys, need your advice once again. I went throw a lot of forum questions but didnt find anything similar to the issue I am facing.

I bought the bike used and the previous owner had installed an Arrow Slipon. I dont prefer loud exhausts but this one was fine. The db blocker is not installed.

On my last ride up and down a mountain, I realised that the backfire sound has changed. I was engine braking coming down and At exactly 3k RPM and below there is a lot of backfire and it sounds very nasty. It wasnt like this before. It feels very raspy and looks like the slipon is damaged.

This started right after I installed Givi frames for luggage. So I thought there must be a bolt that came loose. I checked the whole exhaust today and the frames and didnt find any loose bolts.
The bike is backfiring even cold and at Idle when I rev it up to 4k then let the Revs drop to idle. There is no bad popping when I rev up or hold revs. Only when the revs drop to 3k and below and it sounds

I had changed the air filter and spark plugs in my previous service but it ran fine for the last 4 to 5 months. The bike is more than 5 years old and has a little over 24000 kms.

I actually got used to the popping. it sounded really nice before the issue came up. Now its embarrassing to ride like this and 2 fellow riders already asked me if something is wrong with my bike.
What should be the ideal way to start and diagnose this problem? I have the DB killer and the original exhaust but I rather use the Arrow slip on if its not broken.

Thanks
 

StefanOnHisS10

Converting fuel into heat, noise and a bit motion
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The only thing I can say is that mine does that when the bike is warm and the RPM come down with engine braking. At exactly 3000RPM she starts popping from the akrapovic. Me likey mucho…. :D
 

Iroh

Member
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May 18, 2020
Messages
44
Location
Dubai
Sounds like the gasket/s from header to cylinder head is leaking.
I think this should happen gradually? No suddenly one day it starts sounding like farts instead of bass. Like a torn drum.
 

Iroh

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Joined
May 18, 2020
Messages
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Location
Dubai
The only thing I can say is that mine does that when the bike is warm and the RPM come down with engine braking. At exactly 3000RPM she starts popping from the akrapovic. Me likey mucho…. :D
yes it always did the backfire after 3000 and below. But the sound has changed now to something horrendous.
 

SkunkWorks

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Sep 13, 2018
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Colorado
I would say this is probably normal for these types of slip-on performance type mufflers.
They use a straight-through perforated tube for the exhaust flow, surrounded by some sort of fiberglass or ceramic or metal fibers packed tightly around it.
Over time this packing material degrades from the exhaust heat, and actually gets blown out through the perforations in the tube and out the end of the muffler.
As this happens the sound changes, and will usually get louder and harsher.
Sometimes it happens quickly, depending on the material that was used.
To fix this requires buying a muffler "Re-Packing" kit, drilling out the rivets that hold the muffler together, and sliding out the perforated tube assembly.
Then follow the instructions showing how to re-pack the tube with the new fiber material, and reassemble the muffler with new rivets or screws.
It's not really that hard. I have done them before, and the kits aren't that much money.
 

WJBertrand

Ventura Highway
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Jun 20, 2015
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Did you also install the Givi luggage? If so, maybe the presence of the luggage is somehow reflecting the sound differently?
 

Iroh

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May 18, 2020
Messages
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Location
Dubai
Did you also install the Givi luggage? If so, maybe the presence of the luggage is somehow reflecting the sound differently?
\No I havent installed any luggage. Today I removed everything including the exhaust covers to inspect everything. Tightened all the screws. No difference at all in the sound. Like Skunkworks mentioned, I have a feeling the slipon is bust after 5 years of use.
 

Jlq1969

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May 5, 2018
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Argentina
Before the re-packed, you should install the db killer and test, maybe what increase the sound with wear, decrease when you install the db killer and be more balanced
 
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