De-Catting OE Exhaust
 

Is it possible to de cat the OEM headers and re-use the factory cans , or is it possible to fit the follwing and re use the the factory cans

http://www.calsport.co.uk/YAMAHA/389...s/Remus/113943

Just looking at a cheap way to get rid of the cat possibly.

Thanks

Paul

Succinctly, no. The cat is in the OE silencer.

as per reply above oem cans: cat in the silencer under the seat, with yam supplied Akrapovics the cat is in the link pipes from header to cans near the passenger footrest mounts or thereabouts...
it you were deft with dremel and stainless steel welding then the akra cats should be easy to cut out.

Thanks
 

Thanks for the replies guys , should have waited and looked at my Tenere which is being delivered tomorrow.

so basically a new system is the only option if you have the OEM exhaust.

I modified my own Buell Ulysses exhaust and removed the cat and just thought... Oh well

Better get saving..

Cheers

Paul

well mate, I'm about to cut the stock exhaust to get rid of the (cat)....and I will not be using a "Demel"........unless someone (Yamaha) would be kind enough to inform a poor sucker (such as myself)... what ?.... I should do when the only available fuel source is "Leaded Fuel"...Wonderful bike....but I live in the real desert without a fuel filter and the only fuel is what I can get on the day.....and Yamaha calls it a "Tenere"...sorry for the sarcasam, but I could use some help with day in.. day out....
with a cat in your ass.....
Cheers from Lahami

I'm currently stuck in Ouarzazate in Morocco for a few days with suspected tendonitis in my right arm (too many long days of riding) so I'm considering having a dig at the exhaust tomorrow.

Current thought is to open it up along the seam. Any input welcome.

Tim

Hope you get better soon Tim :sick[1]:

yeah good luck for a quick recovery Tim

my mate suffers the same and I was wondering if the Rally style sponge/foam grips may help ????

Here's where we are so far...

http://www.morocco-knowledgebase.net/tim/P1000926e.jpg

Our best guess is that the cat is in the raised section to the left, i.e. close to the pipe from the exhaust manifold, with the silencer gubbins in the bit to the right. So one plan of action is to cut into the raised bit and have an experimental dig.

http://www.morocco-knowledgebase.net/tim/P1000927e.jpg

View of the bottom of the exhaust box.

And... for anyone who's interested, this is boniyam's Tenere still sitting in Bikerhome in Ouarzazate waiting for parts.

http://www.morocco-knowledgebase.net/tim/P1000925e.jpg

OK, job now done...

http://www.morocco-knowledgebase.net/tim/P1000929e.jpg
Cutting open the standard exhaust exposes...

http://www.morocco-knowledgebase.net/tim/P1000930e.jpg
heat resistent wool held in place by a wire mesh.

http://www.morocco-knowledgebase.net/tim/P1000931e.jpg
With the wool and the mesh removed you can now see the cat.

http://www.morocco-knowledgebase.net/tim/P1000932e.jpg
The cat was cut out and weighs just over 500g

http://www.morocco-knowledgebase.net/tim/P1000933e.jpg
Somewhat freer gas flow now!

http://www.morocco-knowledgebase.net/tim/P1000934e.jpg
The flap welded back again

The cutting, removal and welding cost 20dh (about �1.60) though I gave the guy 30dh as he did such a good job.

Engine response is crisper throughout the rev range, it revs to higher engine speeds more freely and I've gained flexibility lower down. Some of the farting and belching backfires on the overrun now sound more like .22 rifle shots.

So all plus at this stage. :)

Just might want to cover those welds in some hammerite when you get the chance to stop them from rusting. Apart from that good on yea and well done for taking it to yamaha a cutting out that stupid cat:SpinHappy_15XK8L:

Thanks for putting the "in progress" pics up Tim, interesting to see.

Stainless welds on a stainless box...

so can anyone tell me the disadvantage that may occur from this exhaust cutting exercise once using unleaded petrol again when bike back home.
seems a good idea otherwise.........

Nice work Tim.

Block off your AIS now to stop the popping.

I take it that with the cat removed the exhaust will be running a lot cooler than before ... is that the case?

I understand that should be the case but it's been about 30c in the shade here (much more in the sun) and the heat from the exhaust is far more noticeable on the Tenere than on any other bike I've recently owned.

Kev: what's an AIS?

AIS = Air Intake Sensor.

It's the link between the exhaust side of the engine and air box and opens up to burn off unburnt fuel with a closed throttle - or something like that.. It's what causes the bike to pop on the overrun or bang if you have an open single pipe like I do and scare the local wildlife.

If you either block the pipe at the air box end or as I did, remove the pipe completely and cap the air box and engine end with some plastic plugs and silicone adhesive (high temp').

The valve works and is both activated and monitored by the ecu, so you need to keep it connected.

Much better without the pipe..

http://www.xt660.com/showthread.php?...d=1#post101266

air induction system, if you take off the left hand side air box cover there will be a small hole which connect to a tube on the outside try and find a small rubber grommet to block the hole. When you shut the throttle off it let in clean air into the exhaust system to keep the emission reading low and does not effect the performance of the bike at all.

Well done by the way :respeck:

Nice work that man!!! Interesting modification indeed, as said earlier, it will be interesting to see what happens when using UK unleaded fuel once you are back in blighty, but I don't see any forseeable trouble, as the fuel is spent anyway by the time the gas reaches the cat. It would be worthwhile doing a plug chop and have a look at the mixture though, just to see if its not running too lean just a s a precaution. As Kev said, blocking the AIS at the exhaust or airbox end is a simple and effective little mod too. Please post more of your findings as you find out how it goes, as I'm mad keen to do the same to my bike.
Now, pass me that grinder............

Just did the same "surgery" to my stock exhaust,
Quick and easy to do and I'm very happy with the result,
With my Stage 2 and 3 filters and Power Commander 5 there is a noticeable increase of top end power and a subtle increase in noise levels, I also took the opportunity to re spray the exhaust covers, Made the whole thing black instead of the stock black and silver. Will take pics once I wash up ;-)


Thanks for the really good pictures and instructions


Jules

Thanks mate.

Cheers Lahami

May I know how is the sound of the exhaust after removing the cat? Louder?

Maybe a little louder but hardly noticeable


Jules

Another thankyou to Mr. Cullis- just done the same mod assisted by your spot on pics and description. Cheers!

Pete

any chance of a video clip or sound file just for those who might want to do this mod. :applause:

i've just bought a std pipe of eaby and will be doing this mod soon. i'll shoot some video and might even use the DB meter from work to measure the increase in sounds levels.

Foo, the pics have gone :(

I'll post the pics of my de-cat tomorrow.

here is one pic of a set. i'll write up a report soon and post a link to it.

http://i92.photobucket.com/albums/l3...e/P1010206.jpg

thats helpful john thanks

Decat details
 

As mentioned in my advert for my Tenere, I had to remove the catalytic converter from the collector box after it came loose on a long ride. The result was a loud rattling noise at idle and when blipping the throttle, the cat presumably being bashed by exhaust pressure against the dividing wall inside the box and, as pressure subsided, rolling back inside the large diameter tube that houses it.
The obvious solution is to remove the now-useless cat, which may be done as described by others above. Part of the fat tube must be cut back to allow space to remove the cat. This was tack-welded back in place. The cat was bashed smooth on the face that meets the dividing wall, confirming my suspicions above.
I tack-welded the perforated sheet back in place and replaced the rock wool before having the plate welded (using stainless rod).
So the collector is as it was but for the removal of the cat. No extra holes drilled.
As a precaution against lean running I installed a 1k potentiometer in series with the air temp sensor along the lines of the Kev mod (sorry to have to make my own but I was in a hurry) and set it to 0.5k ohms for a test run. By my calculations this should increase fuel flow by about 1.75%. I then checked the plug. The bike was now running significantly too rich, so I lowered the resistance progressively until I now have it at nil (there's still a slight increase due to the baseline resistance of the pot). The plug is fine, perhaps a touch less lean than the old one when changed at service.
Otherwise, the result is as described above: a marginal increase in sound volume but nothing remotely offensive along with an marked improvement in throttle response, especially at the lower end of the rev range. I can stick in a higher gear at lower speeds. No figures on fuel economy yet.
Given that the cat seems prone to breaking loose and then needs to be removed, having it already done seems advantageous to me.
Hope that helps anyone thinking of doing the mod.

Hi mate do you know of anyone who has attempted to removed the Cats from the Akrapovic's supplied by Yamaha for the xt660z?

ive cut mine out about 5 weeks ago

i fitted the kevs fuel mod shortly after ..

i cant find a disernable difference with the fual mod ..but having said that ive only chopped the plug after .. its a nice rusty brown colour so all sems well
the bike is deffo freed up without the cat and is much more flexible and willing to pull low down

i do have a 14 tooth as well but theres no doubt the bike is more flexible and pulls better by far
third will pull from 2k revs ...4th from around 2.3k revs and 5th from around 2.5k revs ..it revs cleaner and pulls harder
with far less fuss and vibration
it eliminates a lot of those caught between gear moments with 30mph being poss in 4th and the low 40s in 5th
for all situations on and off road its much better other than the increased revs on the motorway ..that said a sat nav 75 mph is around 5100 revs
fuel consumption remains frugal and i habnt noticed any increase
all in all its far better than standard and far better than down one tooth on its own ..i can shift between 3 and 4 vibration free ish with clean clean pull which takes me swwetly to 60 plus mph .... it has much more pep and is lovly just to short shift on the torque
top gear just intantly pulls cleand from 47mph on a easy throttle where as before it would just stutter and try and shake itself to peices ..and will pull real urgant from 55mph ..
the combo of the cat and sprocket really wake the bike up ..im delighted with it

... it really is so much better in real world riding /..town off road back road hooning
i can live with a few hundred extra revs on the motorway ... it really is worth the payback the vast majority of the time
thats where i am hope it helps

Thank you for the info...... I'm planning to remove the Cat's from my Yamaha Akrapovic's for the xt660z sometime soon. I haven't decided on Kev's fuel mod or a PCV. How did u remove the Cats? Did u just cut both pipes, removed the Cats, than weld same piece back or did u use a new link pipe?
Thanx JP

ive got to be carful here ....what i can tell you is the bike was run for a short while without the fuel mod and it was fine
its done 1500 miles with it and the spark plug colour is good ....

my cat was just on the standard box ... it seem s a real shame to go to work on 600 quid exhausts .. i hope you figure it

i cant tell you how it was without the fuel mod as i didnt chop the plug but i havnt noticed any difference in the delivery ...

..i found it easier to split the cat housing and prise out the cat ..cutting the rest of the housing after and banging the remaining edges down with a hammer and chisel ..
it messy please wear a mask as allsorts of ****e comes outof the cat when the grinder gets in

http://img14.imageshack.us/img14/2092/img2161q.jpg
By minkyhead at 2011-07-19

http://img838.imageshack.us/img838/8214/img2165m.jpg
By minkyhead at 2011-07-19

Thanx for the info and photo's!!

I read all the thread, but I don't understand if with this mod it's possible to reduce seat's overheating.
I think's yes, but I ask confirm from who make this mod.
Thank's

Yes mate, loads cooler, especially if you drill out the box too!

Drill out the box?
Have you make some new holes in the box, or just make more bigger the existing?

Have you some pictures?
Thanks