Hi there.
Has anybody got a clue about how to eliminate those irritating exhaust blasts/knocks (hope I 've used the right word).
Here's a audio track to show you what I am talking about :

yummy.mp3 - 1.43MB
at 00:14, 00:19 and 00:21.
Is this happening due to poor combustion, and can it affect the engine's reliability in the long term?
My ten has done 3000km already.

Are you irritated by the popping sound?

they all do it, and i like it as long as it isnt deafening.
while driving it doesnt pop a lot, only is moist weather (at least thats what i noticed)

Mine has just done 4000km

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Derbi Senda DRD Sm "04 (black) => BMW F650GS "04 (yellow) => Yamaha xt660z T�n�r� "09 (blue)

It is the AIS system that basically dumps extra air into the exhaust port on the overrun, to ensure any unburnt fuel burns (which is the popping sound you hear) - it's essentially an emissions thing...

You can block it quite simply, or remove it completely with a bit of fiddling around - there are a couple of threads on here with the info - Kev is your man regarding the blocking off instructions...

J x

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"Where we're going, we don't need roads..."

JennyDakar.com

you bike's broke, take it back to the shop and tell them it makes a whip sound...

then run like f***

I' ve done some reading on AIS removal by Kev (thanks Jmo) and the points I concentrate on are:
1.This mod is not recommended for STD exhausts.
2. On any case, removing the AIS will result in less clean emissions and problems with the catalytic converter.

So I guess the only proper way to get rid of the popping sound is by improving the combustion process. Maybe by introducing a second spark plug.

And where exactly do you propose to put this second spark plug?

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I'm always in the sh1t, only the depth varies

We have not had any reports over the past 4 years of any cat blocking up with the AIS turned off. The AIS system does not run all the time with the ECU deciding when to turn it on. Most cats run at 350 degrees C +

I do agree it should only really be carried out with after market pipes.

The best way to sort the fuelling is with a custom made fuel map using a PCV to PCIII.

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Mods that I have done to my XTX's

My 04 XTX
Stage 1 & 2 DNA filters / Kev fuel mod / snorkel mod / Drilled air box mod / Engine breather mod / Fork Spacer mod / 15w fork oil /
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My 07 XTX
Raptor 700 cylinder 102mm / Modified Crank Case to take a 105mm Raptor Cylinder / 11:1 102mm JE Raptor piston / Stage 1 Raptor Hot Cam / Ported head / Colder Spark Plug / +2mm Throttle body / DNA stage 1 & 2 filters / Modified Air Box / Snorkel removed / Worry Brothers stage 2 filter cover / 6mm & 8mm Bolts Replaced with Titanium Bolts / Recovered seat in Black / O2 Eliminator /

My 09 XTX
59HP at the rear wheel / Stage 2 Raptor Hot Cam / DNA stage 3 Air Box / Carbon Can Exhausts / Modified Exhaust Link Pipes / PCIII With Custom Fuel Map / Wideband Commander O2 Data logger / LCD100 Dyno Jet display & fuel adjuster / 2500 OHM HT lead instead of a 10K OHM XT lead / Extra Coolant Cooler / Protaper Fat Bars / Tail Tidy With LED Tail Light / OKE Protection Knobs / LED indicators / AIS blocked / Modified rear sprocket rubbers / Rear Foot Pegs removed / 09 ECU With 02 Sensor Changed To A 06 ECU / Complete wiring harnes Changed from 09 to 04 / Home made LED resistor flasher / Hole drilled in the fuel tank filler neck to allow quicker filling / Modified Bar End Weights / Progressive front fork springs, 15W fork oil, forks lowered 25mm, used XTR rear links lowering the rear 20mm, rear spring one click stiffer / Changed front & rear guards from blue to black / 47T rear sprocket / Speedo Healer V4.0 / Kev throttle cam mod / Throttle grip mod / The new 2010 O2 sensor mod is out, works a treat, The new 2012 O2 Controller is out, PM me for details

Now ride a 2018 MT09SP ABS + TCS

My KTM 990 SMR Mod book. http://www.ktmsmt.com/viewtopic.php?f=13&t=4946

It sounds fine to me and to be honest its a part I like about the bikes when riding. Pop, bang, pop, when you put a decent aftermarket exhaust on it it sounds even better.

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