3653563

[Wrecent_Wryder]

Q6

[furball]

Sounds normal to me with the experience I have had with aftermarket exhaust....You get a lot of popping on decel....My R6 and Busa both did it and so does my SRT-4....it is from the reduction in backpressure....There is slight burrbling in between the pops too...Not sure about GS 500, but it is definitely normal on the other two bikes I messed with the exhaust with....

[Wrecent_Wryder]

T4

[scottpA_GS]

Yep.. thats why I took my V&H off... too much poppin... sounded like crap 

[dgyver]

Here is a good explaination on "popping" from Mikuni:

http://www.mikuni.com/tg_backfires_in_exhaust.html

It is normal for many high performance exhaust systems to moderately backfire or pop when the throttle is closed from mid-to-high rpm. In fact, one should expect a well-tuned high performance engine to "pop" and "crackle" when the throttle is closed at high rpm.

The popping is a result of the air/fuel mixture becoming very lean when the throttle is closed and the engine is rotating well above idle speed. It is also necessary that the exhaust system have rather open mufflers.

Why This (normally) Happens:

1)  When the throttle valve is in the idle position, fuel does not flow out of the main system (needle, needle jet, main jet). Fuel is only delivered to the engine by the pilot (idle) system.
2) The combined effect of the closed throttle and elevated engine rpm is to create a fairly strong vacuum in the intake manifold. This vacuum, in turn, causes a high air flow rate through the small gap formed by the throttle valve and carburetor throat.
3) Under these conditions the pilot (idle) system cannot deliver enough fuel to create a normal, combustible air/fuel ratio. The mixture becomes too lean to burn reliably in the combustion chamber. It gets sent into the exhaust system unburned and collects there.
4) When the odd firing of the lean mixture does occur, it is sent, still burning, into the exhaust system where it sometimes ignites the raw mixture that has collected ---- the exhaust then pops or backfires.

[scottpA_GS]

Here is a good explaination on "popping" from Mikuni:

In fact, one should expect a well-tuned high performance engine to "pop" and "crackle" when the throttle is closed at high rpm.

So.. we are not talking about the GS then right 

[dgyver]

Here is a good explaination on "popping" from Mikuni:

In fact, one should expect a well-tuned high performance engine to "pop" and "crackle" when the throttle is closed at high rpm.

So.. we are not talking about the GS then right 

maybe for some

[Wrecent_Wryder]

T4

[scottpA_GS]

When I had my V&H on I felt the same... I just could never rev it up nice and high cause it sounded way too loud. and going down hills.. ehh... it was non stop poppin and crackin... too loud and not enough performance to justify keeping the V&H... I will stick w/ stock until I upgrade to a bigger bike 

[Kasumi]

I dunno whether this is a related problem/feature/quirk and im just hearing a different sound. But on my ZXR when i shut the power off after brief hard acceleration i get a weird sound like a dump valve, releasing air pressure. Thats the best i can describe it like. Its like: hard engine noise screaming acceleration -> power off -> rpm's drop and a "wooosh" for a second -> then the engine settles back to a steady rpm. Not sure what it is really, it sounds like an intake noise rather than exhaust noise, im not sure of many of the aftermarket parts on this bike as it used to be a race bike, i havn't had time to really identify it but i know its had carb work etc... The exhaust is a full micron exhaust system. i dont hear popping or crackling though.