Home

Go Back   .: XT660.com - The #1 XT660 Resource :. > XT660X & XT660R > XT660X/R Tech Section
FAQ Calendar Search Today's Posts Mark Forums Read Main site

Google

Reply
 
Thread Tools Display Modes
  # 1  
Old 24-03-15, 16:35
Niko Niko is offline
Newbie XT-Moto
 
Join Date: Oct 2014
Location: DK
Posts: 14
Niko is on a distinguished road
Exhaust popping on stock bike

Hello XT forum.

I have a new to me 2013 XT660X that is completely stock and has gone 7800km.

However, the exhaust is popping like crazy especially when slowing down. Is this normal or is it possible that there is something wrong? I dont remember my old KLX250 having this problem.

Thanks
  # 2  
Old 24-03-15, 17:55
Richlybow Richlybow is offline
Expert XT-Moto
 
Join Date: Jun 2014
Location: Staffordshire
Posts: 89
Richlybow is on a distinguished road
My standard 660z pops like corn in the microwave
Sponsored Links
  # 3  
Old 24-03-15, 19:34
seedy seedy is offline
Expert XT-Moto
 
Join Date: Aug 2014
Location: Abingdon
Posts: 85
seedy is on a distinguished road
Quote:
Originally Posted by Niko View Post
Hello XT forum.

I have a new to me 2013 XT660X that is completely stock and has gone 7800km.

However, the exhaust is popping like crazy especially when slowing down. Is this normal or is it possible that there is something wrong? I dont remember my old KLX250 having this problem.

Thanks
TADTS
  # 4  
Old 24-03-15, 20:23
l8ktm l8ktm is offline
SemiPro XT-Moto
 
Join Date: Aug 2011
Location: Forest of dean
Posts: 36
l8ktm is on a distinguished road
Blocking the AIS pipe reduced the popping on my Tenere, it's worth trying.
http://www.xt660.com/showthread.php?t=5544
  # 5  
Old 24-03-15, 22:46
Jacques le Roux Jacques le Roux is offline
XT-Moto SuperStar
 
Join Date: Dec 2013
Location: Newbury
Posts: 830
Jacques le Roux is on a distinguished road
Don't close the throttle completely. I think its the unburned fuel escaping.
  # 6  
Old 24-03-15, 23:07
Pleiades Pleiades is offline
XT-Moto SuperStar
 
Join Date: Aug 2010
Location: North Norfolk
Posts: 5,320
Pleiades is on a distinguished road
The popping and backfiring is perfectly normal. It is (as Jaques says) unburnt fuel igniting in the exhaust when the throttle is snapped shut.

On older bikes (with carbs) like your KLX the fuel wouldn't ignite (unless you had a leaky head/downpipe gasket) as it is starved of oxygen and would just pass out into the atmosphere unnoticed. Current emission regs mean that unburnt hydrocarbons in exhaust gases are a big no no, so air is deliberately introduced to the exhaust port downstream of the exhaust valves to make sure any excess fuel is ignited and burnt off.

On the XT this is known as AIS (Air Induction System) and an ECU controlled valve opens to let air into the exhaust from the airbox to burn off excess fuel when the throttle is suddenly closed. It also opens on a cold start to clean things up as the engine runs rich, and also to speed up the warm-up process as the head, exhaust ports and system will get hotter quicker because of the fuel igniting in them.

AIS is important if you have cats fitted (stock exhaust system) as unburnt fuel quickly damages the catalyst.

If you don't like the popping effect of the AIS (and you don't have cats) then you can simply block or clamp the pipe to the AIS valve that runs from the airbox (or remove the whole system altogether). You cannot just unplug the AIS valve under the tank as its default position is 'open' and the bike will pop and bang all the time!
  # 7  
Old 25-03-15, 00:01
WeaveMcQuilt WeaveMcQuilt is offline
XT-Moto SuperStar
 
Join Date: Jan 2013
Location: Touring
Posts: 360
WeaveMcQuilt is on a distinguished road
I blocked mine for Dyno testing (messes with the test results) but then unblocked it the other day.

Shotgun!
__________________
Bike: 2013 XT660Z, TKC70 tyres

Mods:
Barkbusters, Scottoiler, DIY Tail Mod, DNA Stage 3, Power Commander V & O2 Eliminator, Exan X-Black Stainless exhaust, Tool tube, Ohlins linear front fork springs, Nitron rear shock, JT front and Supersprox rear sprockets, D.I.D. VX 520 chain, Adventure Spec bashplate, DIY USB Outlet, DIY chain guide, Kev's Throttle mod

http://www.facebook.com/onemooseonemotorbike

  # 8  
Old 25-03-15, 05:33
Macca2801 Macca2801 is offline
XT-Moto SuperStar
 
Join Date: Apr 2013
Location: Perth WA
Posts: 242
Macca2801 is on a distinguished road
Sounds awesome!!!! Well at least until you get an aftermarket exhaust... My Barrett single sounded like gunshots going off...fun but a tad disconcerting!

Blocked my AIS port and removed the valve entirely.

Mat
  # 9  
Old 25-03-15, 10:19
Niko Niko is offline
Newbie XT-Moto
 
Join Date: Oct 2014
Location: DK
Posts: 14
Niko is on a distinguished road
Thanks for the feedback guys. I still have the stock exhaust with the cats, so I will have to live with the popping for now. Maybe I will go aftermarkets later but the only system I really like is the OTR 2-1 Akrapovic and its super expensive, not sure I am willing to fork out the money for it, hehe.
  # 10  
Old 25-03-15, 11:09
Macca2801 Macca2801 is offline
XT-Moto SuperStar
 
Join Date: Apr 2013
Location: Perth WA
Posts: 242
Macca2801 is on a distinguished road
Have a read in the linked thread, as you don't have to put up with it despite still being all stock.
You have the choice of blocking the intake air from the air box or you can block the air at the port near the exhaust.
Either way you go, it matters not if you are on stock pipes or aftermarket.
Matt
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +1. The time now is 00:35.
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.

  XT660         Archive   Main site


Footer
vBSkinworks Top