My exhaust is cracking a whip. - .: XT660.com

zeiss11 · # 1 18-01-10, 21:48

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.

Nelis · # 2 18-01-10, 21:56

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

JMo · # 3 18-01-10, 21:57

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

CaptMoto · # 4 18-01-10, 22:01

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

then run like f***

zeiss11 · # 5 18-01-10, 23:25

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.

stumpydave · # 6 18-01-10, 23:46

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

Kev · # 7 19-01-10, 07:27

Quote:

Originally Posted by zeiss11

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.

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.

Tony660x · # 8 19-01-10, 08:11

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.

DickyC · # 9 19-01-10, 10:32

I agree with those that say 'whats the issue with the popping'. Call me childish but I find it quite fun and does not affect anything on the bike or increase wear and tear etc. Its just a by product of modern emission controls and certainly, from my point of view, thats a good thing. If you are going to start 'fitting a second plug' then possibly it would be cheaper to sell the bike and buy a different one, maybe older with a carb etc. as it is clear you are not happy with it and once the bike has been altered permanantly in such a way I think you will find that the resale value falls through the floor.

Anyway, hope things work out for you.

Kev · # 10 19-01-10, 10:44

There are quite a few guys that don't like the popping back, so everyone to there own devices.

The main thing, it does not mean your bike is running lean like 99% of riders think. Fitting a second spark plug would not do much as from 2007 the XT660 went to twin spark motors for emission control.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode