The old exhaust popping!

[DurtyB]

Ok so I just got the bike and have put about 70 miles on it. The bike has a two brothers slip on and naturally I heard the popping on decel and mid shift. Read through a bunch of threads and figured out that blocking off/removing the AIS will help prevent it. Thing is, I don't mind the popping, I actually like how mean its sounds with it. Question is, does it harm the bike? I've read multiple threads with people saying they like it or don't, but is it harmful to continue to let it pop?

Based on the threads I've seen this has been covered a bunch so I apologize in advance, but I couldn't find a straight answer. Thanks.

 

[Banky2112]

I'm no expert, but to my knowledge the popping is from unburnt fuel vapor coming thought the cat and at some point when it gets hot enough and sees air instead of just exhaust fumes it ignites, almost like its flashpoint. I've had all kinds of cars that do it, it never hurts anything. Now if someone on here says I'm way off base then my bad lol but just trying to help you out.

 

[villhelmromero]

Ok so I just got the bike and have put about 70 miles on it. The bike has a two brothers slip on and naturally I heard the popping on decel and mid shift. Read through a bunch of threads and figured out that blocking off/removing the AIS will help prevent it. Thing is, I don't mind the popping, I actually like how mean its sounds with it. Question is, does it harm the bike? I've read multiple threads with people saying they like it or don't, but is it harmful to continue to let it pop?

Based on the threads I've seen this has been covered a bunch so I apologize in advance, but I couldn't find a straight answer. Thanks.

+1

I love the decel popping. I loved it best on my cbr250r with m4 shorty. mean little thumper

 

[master paper clip]

That poping has always been there, the stock can is just really good at killing sound, I ran mine like that for almost 8k mi and no problems here

 

[Harrywz]

I'm no expert, but to my knowledge the popping is from unburnt fuel vapor coming thought the cat and at some point when it gets hot enough and sees air instead of just exhaust fumes it ignites, almost like its flashpoint. I've had all kinds of cars that do it, it never hurts anything. Now if someone on here says I'm way off base then my bad lol but just trying to help you out.

No, you are right about the popping. It usually happens during deceleration. What happens is that the AIS system injects air at the exhaust port, this combined with the heat helps to burn the unburned gases in the exhaust system. Even with the stock pipe you can hear this but with an open muffler like a two bros you will really hear the popping. I've never heard of a muffler exploding from this but is possible. You can plug the air lines to the AIS system without removing the plumbing. This will help with the popping, or get block off plates.

 

[TheFarmer]

You're fine. Popping during decel is sexy. On a serious note, on decel you're lean coupled with PAIR you're bound for some popping.

 

[slowkey]

The only time you must block off the AIS is if you are running a PCV with autotune. Otherwise it is just personally choice.