Exhaust pop

burkerider

burkerider

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Hi people. I recently got a GYTR oval carbon fibre slip in fitted to my FZ1 and love the sound but am concerned about the popping and crackleing sound that the pipe makes when i shut the throttle off at high revs. It's sounds amazing but is this normal?
 
I thought exhaust popping was cool at first, but after a long day on bike it started to get on nerves. I did the AIS block off, it took less than an hour and i seems like bike runs better, but could just be in my head. It did however cure it of the constant popping.
 
No. Exhaust popping is not normal or okay. Exhaust popping indicates a lean condition that you caused by installing the non-OEM exhaust and failing to tune the fuel system to account for it.

While you may be able to eliminate the popping by disabling the AIS system, I would still recommend getting the fuel system properly tuned as it may still be running lean, but not enough to cause the popping.
 
Ive always heard most modern motorcycles run lean from factory and aftermarket exhaust and high flow filter only makes for more lean condition. I am only one on here running Supertrapp homemade exhaust that i know of? As Supertrapp claims you can check fuel/air mix by looking at color of end cap disc kinda like checking a spark plug. Disc with no color or grey tint usually indicate lean condition while anything tan to dark brown is ideal and black being a rich condition. Since removing stock exhaust and no cats, the disc on my Supertrapp are a light brown, which means bike should be running fine. It idles and starts just like did in stock form. I do still have stock air filter and even have exup still connected so its hard to say if that has anything to do with way bike runs. I just know with AIS plugged it no longer pops and sounds great!
 
There's a lot of misinformation about the "poping" you hear after going to an aftermarket exhaust. It's unburned fuel being ignited when the air from the air injection hits the hot, unburned fuel. It was there before the exhaust you just didn't hear it as much. Doing away with the air injection eliminartes the poping because there is no longer that air to ignite the unburned stuff, simple as that and there's no increas/decrease in power because of removing the AIS, just more smog. If you read the information about AIS and similar systems, they'd be left alone.
 
Exhaust popping is not normal or ok...really?

All the AIS is doing (as Lonerider pointed out) is letting air in to mix with the unburned fuel that is coming out your exhaust. The AIS is there for emissions controls. Thats it.

Schrader
 
Lonerider59 said:
There's a lot of misinformation about the \"popping\" you hear after going to an aftermarket exhaust. It's unburned fuel being ignited when the air from the air injection hits the hot, unburned fuel. It was there before the exhaust you just didn't hear it as much. Doing away with the air injection eliminates the popping because there is no longer that air to ignite the unburned stuff, simple as that and there's no increase/decrease in power because of removing the AIS, just more smog. If you read the information about AIS and similar systems, they'd be left alone.
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Thank you for setting this straight. (Glad I read through the whole thread before responding as I was going to say the same thing.) :tup:

There is no harm to the bike, but it does dramatically increase harmful emissions from the bike. If you have emissions testing yearly, it may not pass the EG test so keep an ear to the news and your local shop who does inspections. You may have to reverse the blockoff to pass inspection. ;) This is why I haven't removed mine yet.
 
Broke_Dirty_FZ1 said:
No. Exhaust popping is not normal or okay. Exhaust popping indicates a lean condition that you caused by installing the non-OEM exhaust and failing to tune the fuel system to account for it.

While you may be able to eliminate the popping by disabling the AIS system, I would still recommend getting the fuel system properly tuned as it may still be running lean, but not enough to cause the popping.
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Well as the others pointed out in this case this isn't true. Perfectly normal to have popping once you install a full or slip-on exhaust and leave the AIS functional. You can think of it as popping caused by an exhaust leak. In that case it's popping because air is getting in and combustion is continuing in the exhaust...same thing the AIS is doing.

However, you're not completely wrong and what you stated would be true if you got popping on deceleration and your bike didn't have AIS. Case in point, my '97 YZF1000 pops on deceleration with a D&D slip-on and it's due to a lean condition. While I think it's cool I will get around to installing a jet kit one of these days as it doesn't run all that great at small throttle openings.
 
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FZ1inNH said:
If you have emissions testing yearly, it may not pass the EG test so keep an ear to the news and your local shop who does inspections. You may have to reverse the blockoff to pass inspection. ;) This is why I haven't removed mine yet.
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We have no inspections here unless the machine changes hands.Then it's only a safety inspections. As far as emissions testing goes, none. I could hacksaw the pipe off ahead of the Cat if I could stand the noise. We do have noise emission laws, but they to, are pretty lax.
 
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Oldschool said:
We have no inspections here unless the machine changes hands.Then it's only a safety inspections. As far as emissions testing goes, none. I could hacksaw the pipe off ahead of the Cat if I could stand the noise. We do have noise emission laws, but they to, are pretty lax.
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Yet another reason why NH's motto is a joke... Live free of Die my arse!

Reason #131 to leave NH.... Inspections
Reason #132 to leave NH.... Emissions testing

Nothing beats #1 though... SNOW!
 
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