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Post Yoshimura Install Concern

3248 Views 5 Replies 5 Participants Last post by  KawasakiBrad
I've had my Yoshimura exhaust on for a couple of weeks now, and it's running fine. I instantly noticed that the bike had more pull, and haven't noticed any issues with it running too hot. Sometimes it'll get to 5 out of 6 bars on the temp gauge when sitting in traffic, but it's in the 90's in Texas right now. As soon as I get moving, it goes down.



What I'm a little concerned about is that now I'm occasionally getting a slight pop on decel (engine brake or downshift). It doesn't happen all the time, and it's not that bad, but I was just concerned that it might indicate a problem I need to address.


Any ideas, input, etc would be much appreciated.
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It's perfectly normal. It's the stock fueling cutting the injectors. You just hear it more with a nonrestricted exhaust than you do on a stock system.
It's perfectly normal. It's the stock fueling cutting the injectors. You just hear it more with a nonrestricted exhaust than you do on a stock system.

Thank you Tremonte!
I've had my Yoshimura exhaust on for a couple of weeks now, and it's running fine. I instantly noticed that the bike had more pull, and haven't noticed any issues with it running too hot. Sometimes it'll get to 5 out of 6 bars on the temp gauge when sitting in traffic, but it's in the 90's in Texas right now. As soon as I get moving, it goes down.



What I'm a little concerned about is that now I'm occasionally getting a slight pop on decel (engine brake or downshift). It doesn't happen all the time, and it's not that bad, but I was just concerned that it might indicate a problem I need to address.


Any ideas, input, etc would be much appreciated.
Your gonna hear nonsense sometimes from others that are not exhaust experts. It’s harmless!!
What I'm a little concerned about is that now I'm occasionally getting a slight pop on decel (engine brake or downshift). It doesn't happen all the time, and it's not that bad, but I was just concerned that it might indicate a problem I need to address.
First off, it's no problem and completely harmless.

This is caused by your PAIR valve (aka smog pump, aka AIS) and it's something for emissions standards that dilutes the exhaust with clean air. In a de-restricted (aftermarket) exhaust the unburnt fuel mixes with this clean air and has a secondary combustion event.

If you look up the clean air mod, block off plates, pair valve delete, ais delete you'll get an idea of what that's all about. One of the most popular mods and pretty much mandatory if you're going to hit the dyno or run a wideband o2.

Very easy to do as well.
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