Jump to content
Sign in to follow this  
fairorth

Backfires after installing Yoshi

Recommended Posts

fairorth
I got my Yoshimura (CF) put on this weekend. I've noticed that now on abrupt off-throttle action, the bike will backfire a bit. Small popping sound, nothing terrible but the stock exhaust did not do that. Normal?

My bike history
-----------------
82 VT-500 Ascot
86 VFR Interceptor
04 MV Agusta F4 Brutale S (750)
10 Street Triple R
15 FZ-07 (arrived 12/6/2015)!!

Share this post


Link to post
Share on other sites
jake
My vote is NORMAL.

2015 FZ-07 2003 2014 GSXR 1000

Share this post


Link to post
Share on other sites
Cruizin
 
This is perfectly normal, happens when we change exhausts. Its the air being pushed into the exhaust chamber by the emmisons air pump. You can order block off plates or just plug off the hose from the air pump. Im sure that someone on here has done so on the fz07 and will chime in.
 
 

I got my Yoshimura (CF) put on this weekend. I've noticed that now on abrupt off-throttle action, the bike will backfire a bit. Small popping sound, nothing terrible but the stock exhaust did not do that. Normal?
 

Share this post


Link to post
Share on other sites
shadowcat
Yeah my delk exhaust pops quite a bit I think it sounds cool.
  • Like 1

Share this post


Link to post
Share on other sites
YZEtc
Don't think the FZ-07 has an air pump for emissions.

Share this post


Link to post
Share on other sites
FZRDR
This is perfectly normal, happens when we change exhausts. Its the air being pushed into the exhaust chamber by the emmisons air pump. You can order block off plates or just plug off the hose from the air pump. Im sure that someone on here has done so on the fz07 and will chime in.
 
 
I remember reading the FZ-07 did not have back off plates like the FZ-09?

 

Share this post


Link to post
Share on other sites
FZRDR
It's my dang typing skills, slows me down.... (rofl)"

Share this post


Link to post
Share on other sites
motomeek
Totally normal. I'm a fan of it.

Instagram: @meekmade | You don't need to flat foot a bike to ride it.

Share this post


Link to post
Share on other sites
hobbs
Dobeck said somewhere that the cause of that is air being pulled into the exhaust inbetween firing pulses. Fresh oxygen, heat and unspent fuel vapors combine to create the popping. They called it... reversion.
  • Like 2

Everything went braap.

Share this post


Link to post
Share on other sites
YZEtc
I believe this happens even with the stock exhaust, but is more muffled.
  • Like 1

Share this post


Link to post
Share on other sites
fairorth
See, that's what I was thinking. That the large chambers of the stock exhaust masked the sound. OK, cool. I was thinking I may have left out a part ....
 
I do love the new rumble, huge grin now hitting the start button!

My bike history
-----------------
82 VT-500 Ascot
86 VFR Interceptor
04 MV Agusta F4 Brutale S (750)
10 Street Triple R
15 FZ-07 (arrived 12/6/2015)!!

Share this post


Link to post
Share on other sites
GAZ
It's normal. It's your bike's way of crying because you're getting off the throttle. I have Akra with baffle removed and some people say (that have this setup) it does it often... mine does it rarely. Maybe they don't have a fuel controller. I like it though wish mine did it more.

Share this post


Link to post
Share on other sites
coleman67
It's normal. It's your bike's way of crying because you're getting off the throttle. I have Akra with baffle removed and some people say (that have this setup) it does it often... mine does it rarely. Maybe they don't have a fuel controller. I like it though wish mine did it more.
Interesting.  It has always been my impression that this sort of popping coming off throttle was a result of a lean condition with the fuel mixture.  That's why we check for air leaks - right ? Lean = Hot = Bad.  So, in my mind, installing a fuel controller and enriching the mixture would possibly decrease the popping - just like rejetting carbs would do.  But isn't that what the O2 sensor does?  Somebody set me straight! 
  • Like 1

Share this post


Link to post
Share on other sites
Guest Ralph
The popping is usually due to un-burnt fuel in the exhaust,
if air then gets into the exhaust from air leaks or air injection
that fuel then burns and you get the popping.
My 07 don't do it on the standard exhaust but my old Morini sounds
like the gun fight at the OK corral on the overrun.
  • Like 1

Share this post


Link to post
Share on other sites
GAZ
@ralph and @hobbs got it correct. Reversion. The configurations of the Dobeck are awesome so you could feed it more fuel during a certain stage and in that case it might have left over gases. My comment was directed to the Akra setup and if there was no fuel controller, the misconfiguration of the air/fuel might do this as well. However, I can't speak on behalf of Akra without db and no fuel controller as I do have a fuel controller setup in mine.
 
 
 
  • Like 1

Share this post


Link to post
Share on other sites
JA50N
If it really bothers you, try hi-temp RVT at the exhaust joints to stop any fresh air from being pulled in. If mine does it, that is what I am going to try.
 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  


×

Important Information

By using this site, you agree to our Terms of Use.