Arrow Cat Delete Pipe Install KTM Duke 390 125 250 200

[@gekolizzard]

Once again your vids have proved invaluable. Was trying to get my 390s pre silencer out and couldn’t for the life of me figure out why it wouldn’t fall out once I’d removed the bolts. Then I remembered your channel and presto..job done. Thanks a bunch Dave.

[@MotoMirius]

Well done on getting the job done! And thanks!

[@S57CYL]

Hi all, if anyone will be considering installing simmilar decat pipe I've an advice. You don't have to uninstall presilencer, which is really hard. You just have to loosen it (those bolts from sides, not the lowest one), and uninstall the rear brake fluid tank (right side of the bike). It's very easy to remove the cat through that space!

[@MotoMirius]

Yes, you can remove this way, I've made this comment on other decat videos.

[@ZackaryTheGreat]

Will you make a “how to” video when you do your valve maintenance?

[@MotoMirius]

Yes I will. I have the parts on order so I'm not sure how long it will take for them to come through. Skäl David

[@springy-2112]

Great video David , really concise . Peace and love brother 👍🏻☮❤

[@MotoMirius]

Cheers Springy. Much appreciated as ever. Hope you are keeping well.

[@gekolizzard]

How about a vid on how to remove the spark plug. That’s a Bugga of a job. Just wondering if there’s an easier option than removing the fuel tank and all the plastic bits. Which is what I did.

[@MotoMirius]

Well, as you've discovered, there isn't a lot of room under the tank. People with small hands claim to be able to change without removing the tank. But there is a small hack - I might have to test this, so maybe. If it works I will see about a video! Thanks.

[@emmyjasin]

Great video! Alot of info.. One question, why dont u use the stock muffler, is it that much quieter? Or it just sounds bad.

[@MotoMirius]

Thanks. I often do use the stock muffler, sometimes debaffled and sometimes a stubby version. Akra sounds better and looks better but the stock is actually quite well made. Since you can only buy the Akra from KTM, of course it’s a little better.

[@LuisAlbertoRib]

Hola y gracias. Excelente explicación. En breve llega mi compra del elimina catalizador y hago el cambio. Saludos!!

[@MotoMirius]

¡Gracias y saludos! ¡Buena suerte con el cambio!

[@timmermanlorenzo1962]

HI, I already have a slip on without db killer and airbox lid. I am going to install the RB EVO to avoid running lean. Now i am hesitating if doing a cat delete and leaving the silencer or taking both away, Which one would be best for performance ? and the bike is already loud, will these modifications make it obnoxiously loud ?

[@MotoMirius]

Removing both will make it very loud. I would suggest leaving the silencer - you can always fit a different silencer to adjust the sound level to an acceptable level.

[@arashstar98]

Nice sound man, excellent detail on it and heard the poppin' of flames. Lucky the DB killer went it 😂. Maybe make a video next on how to shoot flames from your exhaust. 😬

[@MotoMirius]

They are known in some parts of the world as 'spark arrestors' not DB killers for a reason lol. Skäl David

[@nidhins6349]

Hai, Great job. Hv some doubts,I removed dB killer from stock exhaust of my duke 250. Sounds good. Then I removed catalytic convert and removed all the stuff inside it and fixed, instead of building bend pipe, Now I notice some drop in lowend torque. So is it bcs of removing dB killer or catalyst converter. No remapping done.

[@MotoMirius]

The evidence would point to the second change. The low end is the most heavily regulated because that is where the bike tends to be most in urban riding. A rough rule of thumb is that one change without adding a piggyback is generally OK, two changes and you need to start thinking about it, so I'd say chances are you need to look at the mapping. You might want to consider the FuelX

[@nidhins6349]

@@MotoMirius okay! thanks a lot 😊

[@jamesjay1987]

Thanks for the video, I got question for you if you can answer: I have 2016 390 bs3 with decat & sc project moto gp (with db killer). Sounds awesome like supermoto bigger cc bikes but I realized little performance loss especially on top speed. Low rpm's more alive btw (I accept lean mixture). A lot of people says we need to remap ecu or use piggyback ecu about this problem and they also says it's dangerous for bike's engine. %70-80 racing bike driver around me do decat & exhaust and do nothing about ecu. Is it really dangerous as they say?

[@MotoMirius]

As you might have guessed, there is no simple answer to this. Yes, the engine is set lean - but the BS3 not so much as later bikes so you are safer. The problem with lean running is that everything is fine until one day your engine blows. Engine rebuilds are much more expensive than remaps/ piggybacks, so you are probably running along that fine line. I had a bike that ran lean and it was all good, until one day it was not....

[@jamesjay1987]

@@MotoMirius So one day there might be a surprise for me ;) I see. Thank you. I am trying to find someone do remap for me.

[@markmitchell8448]

Hi David another great video, I've got a 2018 125 Duke & I'm looking into arrow slip-on cans as the akrapovic is a little bit out of my price range whats your opinion on the arrow slip-on & what all mods have you done to your 125 very nice bike m8

[@MotoMirius]

Hi Mark and thanks. I bought a used Akrapovic as I wouldn't be spending that much either. Arrow have a great reputation for exhausts and I've bought them before, just not for the Duke, so can't comment too much on how they will sound. The mods on my 390 vary from time to time and I tend to forget them all. Off the top of my head - 16-50 gearing (will be 14-50 shortly), Powerparts engine crash bars, Magura X-Line handlebars, Bagaros two finger clutch lever, Powerparts seat and rear seat cover, Bagaros sticker kit, Galfer front disk, arrow cat delete, Akra with protector, Bagaros rear cage, Bagaros wheelie bar, RapidBike Evo Exclusive piggyback.

[@markmitchell8448]

@@MotoMirius ooo well jealous, you have all the Bagoros & KTM Powerparts I'm looking into getting, was the leo vince de-cat link pipe a bit on the loud side?

[@MotoMirius]

@@markmitchell8448 Leo vince was fine - bear in mind that it has the additional silencer built in so it's not as loud as the cheaper pipes you can get. I've not had chance to ride this yet and probably won't for a few weeks yet so the test will be how loud it is without the baffle. Bagaros have also recently launched a cat removal pipe. They have dyno tested it with good results - the LV is also recommended by people who sell performance pipes.

[@markmitchell8448]

@@MotoMirius Perfect thank you for all your help & info keep up the great videos always a cracking watch

[@markmitchell8448]

@@MotoMirius Hi this is a bit of a random question but do you know what the weight of the stock end can on the 125 duke I cant seem to find it anywhere

[@giuseppecrispo703]

does the performance increase by removing the catalyst? does the engine run freer? thanks for the answer I always follow you compliments.

[@MotoMirius]

Thanks. Yes more power is available but you need to run a piggyback to properly benefit.

[@giuseppecrispo703]

@@MotoMirius by installing a rapido bike Easy can i solve It by increasing Power? I have already changed the filter and mivv terminal

[@MotoMirius]

@@giuseppecrispo703 If you want power then I suggest spending money first on a proper piggyback not the entry level version.

[@giuseppecrispo703]

@@MotoMirius ok thanks

[@connorpitts639]

Hi moto mirius. I plan on decatting my ktm duke 125 and following this exact method. Is there anything I should be aware of after doing this? Also the bike is stock and replacing exhaust with an arrow slip on and de catting the bike is the only change I will be doing. Thanks in advance.

[@MotoMirius]

No, process should be much the same and just the decat should be fine. Make sure you get the 125 pipe - I think they are the same but it's possible there is a difference. Unbolt the rear master cylinder from the frame to give you room to turn and wiggle out the existing cat and loosen the presilencer so you can snuggle the parts back together for a good fit and you should be good. If you get an engine light and it doesn't go away after a few miles then you may need a unit like the FuelX Lite. Good luck!

[@heimwerk84]

Amazing video !!! Thank you !!

[@MotoMirius]

Glad you liked it! Thanks!

[@manfredstammel4447]

Two questions: a) Are there any disadvantages for the engine as they are e.g. for a car with a 3-way cat delete? b) Would that also work on a EURO 5 model 2021? Thanks

[@MotoMirius]

The cat is for emission control - it has no function for the engine - but the fuelling of the engine will be adjusted to compensate for it. Yes, there are cat delete pipes for the BS6 model - but I would recommend a piggyback to adjust the fuelling for those.

[@manfredstammel4447]

@@MotoMirius Thanks for your quick response. Great video by the way. Do you know if there is a difference between exhausts for the Euro 4 and Euro 5 model? There are much more slip on‘s for the Euro 4 model available but I don’t know if they fit on mine.

[@MotoMirius]

Thanks, yes they changed the connector between the slip on and the presilencer so they are not compatible unfortunately @@manfredstammel4447

[@cavitecheckpoint]

If you remove the cat and left the pre silencer will you still need an ecu? Always informative video😁

[@MotoMirius]

Thanks. My rule of thumb is that one change is normally ok on the stock ECU.

[@kawabungatortueninja]

Is it possible and smart to put a bigger cat so there would be more airflow but it will be less noisy and eco/police-friendly?

[@MotoMirius]

You'd need to have one custom made and you are restricted by the space available - you don't want it any closer to the airbox and throttle body than it already is.

[@kawabungatortueninja]

@@MotoMirius thanks David, I ll try if I find the right component

[@mhbmarcos]

Is it necessary to remap for this change (with powertronic, PC, etc)?

[@MotoMirius]

It depends. Generally, if it is the only change you make then you should be fine so long as you don't live somewhere extreme. But personally I always err on the side of caution because a basic piggyback is much cheaper than an engine rebuild. Skäl David

[@ark1289]

Hi, how much more sound does this make compared to the stock? Like percentage wise. Ty. Love your videos

[@MotoMirius]

I would say about double - let's just say I have to keep the baffle in to avoid undue attention if I want to open the throttle. But it's not so much about how loud, but how good it sounds. It's easy to make something loud, but much harder to still make the bike sound good, and this does it very well. Decat is definitively one of my favourite exhaust mods on this bike.

[@ark1289]

@@MotoMirius cool, will get it on my 2013 duke 390. Ty

[@MotoMirius]

@@ark1289 You'll need the complete system from a gen 2 bike if you don't already have on as the joints are different.

[@ark1289]

@@MotoMirius o crap, so I can't keep the stock silencer? Yup, it's a single piece for both cat and silencer. Aaargh. Thanks anyways tho

[@Feenyu]

Once you take that resonator out , do you need a filter x to keep the performance of the bike in touch ? They say once you take that out , your bike on high speed loses strength

[@MotoMirius]

It's not a resonator - it's a cat. If it's the only change you've made, typically you are OK, but a FuelX Lite is never a bad option (FuelX Pro is typically a bad option unless you know a lot more about tuning than the average rider). I don't know who 'they' are but I've never seen any evidence to support this. Removing the presilencer has been shown to reduce mid range power, which is why I don't recommend it (unless you are replacing with something similar).

[@Feenyu]

@@MotoMirius So the Big ole black part in the middle is a cat ?

[@MotoMirius]

No the big black part is the presilencer. This video is not about that, it is about cat removal - so nothing to do with the big black part - which is ugly and works well to reduce noise levels but has little adverse impact on power. If you ask me questions about the presilencer on a video about the cat, you need to explain what you are talking about ;) @@Feenyu

[@Feenyu]

Sorry if the question bother you . Great content thanks again

[@MotoMirius]

thanks - question doesn't bother me, but I didn't understand your original question, so we missed the point at first.@@Feenyu

[@Mikeburrows92]

Hi great videos I’ve watched a few 👍🏼 I’m thinking of getting a full decat pipe like the arrow one you had that has the cone shape silencer, was it too loud even with baffle in? Does it sound better with the small one you’ve got now and pre silencer? was it difficult to refit that black pre silencer cause it looked a very tight fit before it was knocked out haha

[@MotoMirius]

Arrow make great exhausts - I've had a few and never regretted it. As you may have noticed, I use the modularity of this design to play with the sound levels. Cat and presilencer delete was great with the Akra slip on so long as the baffle was in. Some places you might get away with the baffle out but I found myself pulling the clutch in and rolling on idle past police cars. With this I'd get away with the baffle out - I'm going to be trying different baffles just to fine tune. Trick with the presilencer is to shorten the lower mounting tube - what happens is that the tabs on the frame bend a little when they tighten it down in the factory but with the lower tube shortened a faction its a slip fit - as you could see here. Have fun! Skäl David

[@Mikeburrows92]

@@MotoMirius oh great did you have to take much off the tube about 20-30mm I’m guessing?

[@MotoMirius]

@@Mikeburrows92 More like 2-3mm. It's a sliding fit between the frame tabs.

[@gekolizzard]

@@MotoMirius yup took your advice and ground off a couple millimetres. Worked like a charm after that. Still had a bit of a struggle but it was easier.

[@Thevoiceofsense]

Hello old bean, I e debaffled my 2023 duke 125 exhaust, much better. Now I want to decat and get the arrow pipe as yourself, however, do you recommend also getting that fuelx piggyback? Or is it not needed?

[@MotoMirius]

If you have debaffled and are looking at the decat then I'd recommend something like the FuelX Lite - that way if say you upgrade your air filter, you are still good to go.

[@Thevoiceofsense]

@@MotoMirius cheers pal

[@Thevoiceofsense]

@MotoMirius one more question bud, how much extra oomph do you guess it might give to decat?

[@MotoMirius]

@@Thevoiceofsense Hard to say, I'm not sure anyone has actually measured it. It would be nice to have the budget to dyno every change and be able to provide a definitive build path. I've been running the decat for a few years now - not even sure what a stock bike would feel like.

[@Thevoiceofsense]

@@MotoMirius I'll try and gauge it when I'm done ;)

[@AJ-hg2vj]

Do you lose power if you only decat the cat and leaves the pre silencer on? And the Stock silencer/muffler (i dont know) With the stock ECU. Sorry for my Bad englisch But i think you know what i mean :)

[@MotoMirius]

Dyno tests show improved power with decat/ presilencer over decat with presilencer removed. Presilencer does not reduce power

[@DeclanShaw-nt2nv]

I know the video is old, I installed a full black widow system including a de cat and now the engine light is on? Any suggestions?

[@MotoMirius]

Have you added a piggyback to correct the fueling?

[@Tryneditjfan]

I got a Ktm duke 125 2021, but can i put on a Arrow decat on the bike? Because i can not see a decat like your bike has. Please answer

[@MotoMirius]

If you have a BS6 where the exhaust runs under the engine then you will need a different decat pipe. New models don’t have as much choice in aftermarket parts but I think Coober or Bagoros Performance have them.

[@Tryneditjfan]

@@MotoMirius could you do a video of that? put a decat on ktm duke 125 2021

[@MotoMirius]

@@Tryneditjfan I don't have a BS6 Duke, so I won't be able to do that.

[@mprpitbike8935]

If I did this to my bike with that arrow decat and the arrow slip on and Road it for a few weeks before I get a remap map would the bike be okay

[@MotoMirius]

Depends how much and how you rode it. Typically it will be fine, but try and get a piggyback in there soon. Consider the FuelX if you have no plans to do major mods or track the bike.

[@yngvehannevig3471]

Thinking about getting this on my ktm 125, will it be alot louder? i have removed the db killer on the stock muffler

[@MotoMirius]

Removing the cat makes it a lot louder - but you still have the presilencer so it isn't too loud

[@wanshaneleazerdiengdoh284]

hey David....how did you purchase the arrow cat delete?....can't seem to find it online

[@MotoMirius]

I recall that I bought mine on eBay. If you do a search of the part number on the Arrow site you should find a reseller.

[@wanshaneleazerdiengdoh284]

@@MotoMirius Would it be alright if you could share the part number with me?

[@MotoMirius]

@@wanshaneleazerdiengdoh284 Parts can be found here: www.arrow.it/en/assembled/1550/KTM-DUKE-390-2017 Click on the Where to Buy link to find your local dealer

[@xero2957]

Hi everyone, recently bought a new 23 plate ktm duke 125, and im struggling to find a decat pipe to replace the cat box, if anyone can help me it would be much appreciated

[@MotoMirius]

If it's the under the engine exhaust then the cats are in the pipe under the engine - not in the black box - this is just a silencer.

[@alfonsolopezperabad3874]

Do i need a Fuel X Lite or similar for a safe decat or it isnt necesary ? I got a 2017 Duke 390 with a arrow exhaust and im planning to decat the bike for better sound

[@MotoMirius]

As a very rough rule of thumb, one change to the exhaust is normally OK, two and I'd recommend playing safe. As I always say; engine rebuilds are a massive pain and very expensive, so it just isn't worth gambling with the relatively small expense for the Lite.

[@alfonsolopezperabad3874]

@@MotoMirius thank u Buddy really apreciate the Quick response

[@alfonsolopezperabad3874]

@@MotoMirius I have finally decided to go for the Rapid Bike easy, I am sticking to the plan to de-catalyse the bike and fit a kn air filter or similar but keeping the original filter cover. What do you thing about this move?

[@MotoMirius]

@@alfonsolopezperabad3874 I would suggest you consider the FuelX Lite (do NOT buy the FuelX Pro) instead of the Easy - the Easy is an old model that Dimsport are in the process of replacing with a better module.

[@kevinpinheiro2485]

If I do the same. Will the bike need an ecu re flash ? Also is it louder ? I will only be doing decat. Stock pre muffler and stock muffler

[@MotoMirius]

Yes, it will be louder, no reflashes are not recommended because the ECU is locked, a piggyback is recommended but most riders will probably be OK so long as no other changes have been made - so no air filter mods, not just exhaust. But running without piggyback is always at your own risk.

[@kevinpinheiro2485]

@@MotoMirius currently I have not done any air filter mods. Only de baffled the muffler. I made it like yours where I can re insert it and bolt it back on. I’m facing some heating issues basically and a lot of heat near the cat. Buying a new cat isn’t possible and I wanted to try out a decat pipe. My only concern is engine reliability. Like would I still need a piggyback ecu or can I get away with it

[@MotoMirius]

@@kevinpinheiro2485 Heat there is typically a result of air being blown over the header pipe not the cat especially if the fan kicks in - very well known issue in hotter countries, although the cat does get hot, so decat may or may not help. As I said, most riders will be fine, but I don't know where or how you ride so I can't give you a definitive yes or no as to whether you will be fine. A piggyback is the safe option and Race Dynamics comment that the FuelX Lite helps the engine run cooler (because they are based where lots of people have this issue) even with the CAT.

[@bemoan01]

What do you mean by pre silencer ? I did not understand . Do you mean stock silencer ?

[@MotoMirius]

The presilencer is the black box that sits in front of the rear wheel.

[@brentmichiels7500]

Hello mirius i have added a decat and another exhaust, but wont start now, only if i give gas all the time can it be a problem with the lambda? Maybe the bike add more fuel ? Greetz!

[@MotoMirius]

Try putting the stock slip on back on. I don't recommend decat and modified exhaust unless you have a fuelling device to add more fuel.

[@brentmichiels7500]

@@MotoMirius oh ok thank you bro! So i need to upgrade fuel injection? Greetz

[@brentmichiels7500]

@@MotoMirius should rapidbike evo help maybe?

[@MotoMirius]

@@brentmichiels7500 The RB Evo is an autotune module like the factory ECU but without the emissions controls, so yes it is a plug and play solution to correct the fuelling. It depends how much you intend to modify the bike. A cheaper solution is the Fuelx Lite (not Pro) but you get what you pay for.

[@brentmichiels7500]

@@MotoMirius oh ok mate, best way is maybe going to a dealer? Ty soo much for al the information mate!

[@jackcoker483]

Hi mate do you know if the arrow exhaust for the ktm duke 125 is the same as the duke 390

[@MotoMirius]

The only difference between the 125 and 390 exhausts on the gen 2 bikes is the header pipe. From the cat backwards they are the same and the frame is the same too so no reason for the Arrow to be any different. Obviously if new buy the 'correct' part but I've mixed and matched 125 and 390 exhaust parts without any issue. Skäl David

[@Bbarniify]

Isnt it a 390 duke with 125 fairings? 24:30 Love the Grenzgaenger gear:)

[@MotoMirius]

Thanks! Yes, it has 125 rear fairings - mine were scratched so I swapped these on and I haven't got around to pulling the 125 stickers off them yet.

[@sennehaccuria7436]

The top speed of my duke 125 2021 is around 100-110km/h, can i increase this speed by just a decat?

[@MotoMirius]

Decat may help but you will find that increasing power is made up of many small steps, of which decat is one.

[@Michael_Douglas007]

Ya it may help but it won’t be a very visible gain.

[@gradydowning2193]

Do you have to remap the bike after putting the after market exhaust in?

[@MotoMirius]

Small changes are normally ok, but stock ECUs especially from EU and UK manufacturers are tightly controlled by emissions regulations and that includes locking them to prevent remaps. For bigger changes to the exhaust some form of piggyback ECU is recommended, from the cheap ones that tweak a sensor reading to the expensive toys for big changes.

[@aktm4u]

Wonder if this will work on the 390 Adventure model?

[@MotoMirius]

The 390 Adventure has an underslung exhaust where the cat is built into the header pipe - so no, you need a different modification.

[@plopkoek5423]

Quick question is the width of the pipe coming out of the pree silencer from the 125cc the same width as the 390

[@MotoMirius]

The presilencer on the 2017 to 2021 small dukes is the same regardless of which model so the pipes are therefore the same. The slip on is also the same across all the small Dukes of that period.

[@plopkoek5423]

@@MotoMirius okay thank you bro

[@Rcriderkannada]

I there any problems will I remove stock decat. And install a moded one

[@MotoMirius]

Depends what other mods you have. To be safer consider adding the FuelX Lite (not Pro)

[@greenblue980]

​@@MotoMirius is it also safe to tune on afr only, not the whole remap process

[@MotoMirius]

@@greenblue980 FuelX is only AFR. You get what you pay for - FuelX is the cheap entry point - if you get better systems then you get a better map. Safe depends on just how modded your bike is.

[@elio3261]

Hola, he logrado quitar el catalizador sin desarmar el resto del sistema de escape.

[@MotoMirius]

Sí, normalmente es posible desatornillando el depósito del freno trasero. Pero a veces la pieza nueva no encaja exactamente igual, por lo que una buena práctica es aflojar el resto del sistema y volver a montarlo desde el gato hacia atrás.

[@radioitaliana2.038]

Hi but of i do this, i must touch the centraline or not?

[@MotoMirius]

I don't know what a centraline is.

[@fullthrottle0324]

will decat shoot flames from the exhaust in duke 250 2018

[@MotoMirius]

Unlikely. Whilst the CAT may assist in that, stock exhausts are designed to suppress this.

[@fullthrottle0324]

@@MotoMirius should i use a spark plug for that in the exhaust

[@MotoMirius]

@@fullthrottle0324 No. Flames are a result of unburnt fuel and/or the result of using a very short exhaust with no or minimal baffles (which are partly designed to prevent flames since these can be a fire hazard).

[@MFETmusic]

Do you need a map / tune after fitting the decat?

[@MotoMirius]

If the bike is otherwise stock, you should be OK, but a simple fuel controller such as the FuelX Lite would be recommended.

[@MFETmusic]

Thanks for the reply. I'm stuck between cutting the silencer down and removing the baffle or just fitting a decat . Just want a bit more volume. Not bothered about power gains. Just want it to run right and be bale to hear it

[@MotoMirius]

The decat is always my choice - but not removal of the presilencer. That allows you to play with the slip on to make it a bit louder or quieter as you prefer. I tend to recommend some form of piggyback as modification is a bit of a slippery slope - after a couple of months the temptation can come again@@MFETmusic

[@wernerxldata]

I removed the rear brake fluid cup, then you can move the cat out of the way without removing the presilencer.

[@MotoMirius]

Yes you can indeed - this is what I tend to do.

[@wernerxldata]

@@MotoMirius As far as I could see the fit was quite perfect from the arrow wasn't it ? Ordered 'another' brand myself few weeks ago and tried to get it on. There was no way in the world it would fit without a grinder and a welder. I'm gonna send it back and order me an Arrow, it looks slicker too. and nice tip to grind an mm of the tube at the bottom of the presilencer, it was a bitch to get back in without :) So thanks for the video, although it is a bit older it was still informative and fun to watch !

[@MotoMirius]

@@wernerxldata Well that is true but even when refitting a stock system you will often need to jiggle the system around when refitting - this is why I didn't show the the rear reservoir trick but instead loosened off the presilencer - it makes refitting much easier as it will often be just a tweak needed to get it all to line up.

[@wernerxldata]

Question, maybe you know the answer to this. I’m still in doubt if I want to decat or not, I run a dna airfilter combined with an Akra slip-on without db killer. I actually don’t have the db killer. In my opinion the bike shouldn’t be more loud than right now. So I figured when I decat it I’ll have to add the db killer, can just order one. But will that make sense, I’m curious what would have a more negative influence to the airflow, the cat or the db killer. Do you have any ideas about this ?

[@MotoMirius]

@@wernerxldata Yes, you will need to add back the db killer - will probably still be a little louder than now, but not much. I've not measured but I would say the cat is likely a bit more restrictive to airflow purely based on the sound levels.

[@aleksanderglunde7673]

Did you have the stock db-killer in the video?

[@MotoMirius]

If you check at kzbin.info/www/bejne/m6fFl5Sjft6mf6c you will see I am using the KTM supplied Akra with the standard Akra db-killer in it. Standard Akra with db-killer is similar in terms of sound to the stock slip on which has had baffle removed and stubbied.

[@TheJWC56RSA]

Great info as always. Those decat pipes are just much to expensive. I'm thinking of just "hollowing" out my cat (removing the inside - done it with numerous other bikes) and see how it goes.... Regards.

[@MotoMirius]

I actually edited out the part of the video about doing just that. I strongly recommend not doing that unless you are able to do so in a properly safe environment. A little cash saved isn't worth the long term health risks associated with the inhalation of the materials inside the cat.

[@nandhakumarv2851]

Bro i need duke200bs6 exhaust sound change in bs4 model sound

[@MotoMirius]

We don't get the BS6 or the 200 here. BS6 looks like the cat is built into the header.

[@jovreb4727]

Can you send a video without the db killer? Is it to noicey?

[@MotoMirius]

Noise levels are really hard to compare on video unless you have a specialist microphone - normal microphones cut off at well below exhaust max sound levels so all exhausts sound just as loud - unless you are 50m away. I will try it without the DB killer because I am curious too - but it will have to wait until we are out of lockdown! Skäl David

[@mattteusz]

Is this possible to replace this small cat like in your video and in the same bike replace a big decat?

[@MotoMirius]

There is no big decat - there is only one cat on this generation of bike. You can replace the presilencer but it doesn't help with power.

[@mattteusz]

@@MotoMirius so what is the best for duke 125 2019?replace this short cat to arrow or replace the presilencer?btw why at the end of this video your duke automaticly turns off?

[@MotoMirius]

@@mattteusz My recommendation is the short cat delete. If you really don't like the look of the presilencer then choose something like this www.leovince.com/en-gb/product/8086-cat-eliminator-link-pipe-ktm-duke-125-2017-2020 instead - not just a straight pipe. You can buy them second hand - the 125 and the 390 share the same exhaust (only the header is different).

[@mattteusz]

@@MotoMirius thanks so much and why your duke at the end of the video automaticly turns off??

[@MotoMirius]

@@mattteusz Because the engine was cold :D

[@mmzpatriot5029]

hi may i ask, many ktm owners said dont remove silencer/resonator. just muffler exhaust and decat is good to go. and others say different which dont delete cat, just slip on muffler and remove resonator. if delete cat will damage the engine and afr. what is your view? im planning to get akrapovic slip on for my duke 390 and third party catalytic converter but will remain stock resonator

[@MotoMirius]

Dyno testing has shown that removing the presilencer creates a loss of mid range power. People like to remove the presilencer because it is ugly and they care more about the look of the bike than anything else. If you alter the exhaust to make it more free flowing then it will affect the AFR and you should consider fuel management. The Akra (Akra are a KTM partner so everything is tested) can be fitted with no fuel adjustments needed. If you do more than this such as cat or presilencer removal then you would be highly recommended to fit a fuel management device. Beyond this there are no 'right' answers, you should do what suits you - but presilencer delete will make the bike much louder.

[@xanders9767]

hi great video, i have bought a decat pipe ,but if i install this on my duke 125 do i need to tune the bike or put a new ECU in?

[@MotoMirius]

Thanks. If it is the only change you have made - so stock slip on, no airbox lid, keeping the presilencer etc then you may be OK. I would recommend playing safe and considering the FuelX Lite for example which will also improve the running of the bike.

[@jeanpascalferrand4349]

hi david, the link about this decat arrow doesn't work

[@MotoMirius]

Hi, Thanks for that. Link is now fixed - seems to run slow for me, but maybe just my connection today. Skäl David

[@AJ-hg2vj]

Can you Show it with the Stock muffler?

[@MotoMirius]

Once I've figured out how to record sound well enough for you to hear how it really sounds, then yes, I will do that.

[@prinxe9466]

Is the smoke coming out of his bike a problem??

[@MotoMirius]

No, it's a mix of choke and cold air on first start and some valve seal leakdown. If I let the bike warm up and then did the video, you wouldn't see it.

[@basidhsajan2398]

Is there any power difference bro?

[@MotoMirius]

Dyno tests by Coober says yes. But as with any change on a bike this small, it's not going to be a lot. It's all about the incremental increases.

[@basidhsajan2398]

@@MotoMirius how much whp bro

[@duey36]

do I need to remap the computer after this?

[@duey36]

Got my answer in the previous comments. i was worried cant afford a new ECU if I do this and remove the baffle. I owned many different bikes over the years and my Duke 390 is probably the most fun I have add since my 1995 CBR600F3

[@MotoMirius]

You might consider adding the FuelX Lite

[@KaRim-es9xx]

Hi, what about the Bagoros Decat? Thanks ✌️

[@MotoMirius]

It’s awesome and it has a great price. It was also tested on a dyno and produced more power. I might have bought it but I’d already bought this one. Skäl. David

[@KaRim-es9xx]

@@MotoMirius Thanks David. The decat is coming soon ✌️ Is the Powertronic necessary and efficient on a little duke 125? On the 390 it’s a good option but on a little gear...?

[@MotoMirius]

@@KaRim-es9xx engine size does not drive this but how lean the engine runs. If you are just running a decat then Powertronic is probably overkill. But if you plan on doing more to the bike then it will serve you for that.

[@KaRim-es9xx]

@@MotoMirius for now just the decat and debaffled but you know how it works, when you start mods ....😂 Thanks for your great job on you tube👍

[@MotoMirius]

@@KaRim-es9xx I have no idea what you mean! This is why I chose a full piggyback with autotune and not PowerTRONIC - because otherwise I'd have to remap every time I got bored and swapped the exhaust and airbox around.

[@Dirik777]

Engine guard ka name batow bhai ?

[@MotoMirius]

KTM Powerparts

[@macco7233]

It dosent fit on my 390duke 2021 mod….

[@MotoMirius]

No, it won't fit the BS6 models - but you can instead fit a cat delete made for them.

[@MrUncleFAT]

Are you still able to connect both like arrow pipe and leo vince decat pipe together?

[@MotoMirius]

Both arrow and LeoVince do a pipe that replaces both the cat and presilencer - this is a single long pipe and can't be used with the cat only delete pipe. Two different solutions - one replaces two parts of the exhaust system, the other only replaces one part of the four part exhaust system - header, cat, presilencer, silencer.

[@MrUncleFAT]

Thanks a lot and sorry for my stupid question 😅

[@MotoMirius]

@@MrUncleFAT Not a stupid question! The only stupid question is the one you don't ask! Someone else might have wondered the same thing and it doesn't help you if you aren't sure.

[@MrUncleFAT]

Could you tell me about this too if I put open air filter and LeoVince decat pipe and Austin Racing exhaust pipe is it correct to install this Rapid Bike EVO CONTROL UNIT KIT . Or EVO EXCLUSIVE also good?

[@MotoMirius]

@@MrUncleFAT Evo and Evo Exclusive are identical units in terms of what they do. The difference and why you pay more for the Evo is because you can unplug it from the Duke, reprogram it and use it on a different bike. I am not convinced that by the time you've bought the new loom for the new bike and had the unit reprogrammed that it is cheaper than selling the Exclusive and buying a new Exclusive for the new bike.