Exhaust/Catalytic Mount Cracked

[devriems]

I took off the left side fairing yesterday on my 2018 RC390 and found that the catalytic converter had cracked where it is mounted to the frame. It looks like it's some sort of ceramic material, so I don't think I can weld it back together. Despite it being cracked and not actually being supported by the mount, it doesn't seem loose at all. Anybody else have this happen and if so, what did you do about it, if anything? Thanks. Pics below.

 

[devriems]

And actually, I think that might not be the catalytic converter that's cracked (I think its upstream from there), but some sort of silencer box. Not sure.

 

[Karfanatik]

And actually, I think that might not be the catalytic converter that's cracked (I think its upstream from there), but some sort of silencer box. Not sure.

Its called deadweight. The cat is indeed a bit further up. The black box is a presilencer. Personally I would fix it (decat and PCV) but it also probably not going anywhere

 

[devriems]

By decat you mean something like a 3/4 exhaust or perhaps just the decat pipe and chamber delete pipes from from Comp Werkes like linked below, right?

KTM RC390 Duke 390 Vitpilen Svartpilen 401 | Mini Cat Delete

Order this KTM RC390 Cat Delete pipe for your motorbike today. This Catalytic Converter Delete is compatible with any slip-on designed to fit the stock exhaust.

www.competitionwerkes.com

KTM 390 Duke RC390 Husqvarna Vitpilen 401 | Chamber Delete

This link pipe allows you to remove the heavy muffler/pre-chamber that sits inside the swing arm of your 390 Duke, RC390 or Vitpilen/Svartpilen 401. Hand welded in the U.S. Full stainless steel construction No tuning or remapping required Off-road use only, not street legalFits:RC390 2017+390...

www.competitionwerkes.com

 

[Karfanatik]

By decat you mean something like a 3/4 exhaust or perhaps just the decat pipe and chamber delete pipes from from Comp Werkes like linked below, right?

http://[URL]https://www.competitionwerkes.com/products/wkt391cd

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http://[URL]https://www.competitionwerkes.com/products/wkt391d2

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Yep you can go this route or do one whole piece with a Leovince link pipe. You got options but if you're messing with the cat converter then you need to make sure the fueling is done proper as well.

 

[devriems]

I wonder if I were to just get rid of the pre-silencer and leave the cat converter and muffler if that would require a PCV or ECU flash. Not ideal, but looking into a complete exhaust and a PCV is getting up there in cost. Pay to play I guess .

 

[Karfanatik]

I wonder if I were to just get rid of the pre-silencer and leave the cat converter and muffler if that would require a PCV or ECU flash. Not ideal, but looking into a complete exhaust and a PCV is getting up there in cost. Pay to play I guess .

I had also wondered that before doing all my mods but never got a real answer. I don't think you would NEED a PCV if its just the black box going in the bin and everything else stock.

 

[ClydeXreY]

I took off the left side fairing yesterday on my 2018 RC390 and found that the catalytic converter had cracked where it is mounted to the frame. It looks like it's some sort of ceramic material, so I don't think I can weld it back together. Despite it being cracked and not actually being supported by the mount, it doesn't seem loose at all. Anybody else have this happen and if so, what did you do about it, if anything? Thanks. Pics below.

View attachment 7113 View attachment 7114

I also had the same problem twice, once on my ktm rc and the other on my buddy’s duke 390.. I experimented and welded mine with ss304 back to back and the duke’s with n99 and surprisingly even though we’ve got some shit roads they both held up fine mine for 3 years and the duke’s est. more than a year now.. I do have cat and silencer deletes on hand so I’d get to get rid the stock when they break but they are surprisingly intact..

 

[devriems]

I also had the same problem twice, once on my ktm rc and the other on my buddy’s duke 390.. I experimented and welded mine with ss304 back to back and the duke’s with n99 and surprisingly even though we’ve got some shit roads they both held up fine mine for 3 years and the duke’s est. more than a year now.. I do have cat and silencer deletes on hand so I’d get to get rid the stock when they break but they are surprisingly intact..

Interesting. I've got a MIG welder setup for mild steel. Don't currently have any way to weld stainless and that n99 looks like something I'd need to use a stick welder for, right? I wonder if JB Weld would hold up....

 

[ClydeXreY]

Interesting. I've got a MIG welder setup for mild steel. Don't currently have any way to weld stainless and that n99 looks like something I'd need to use a stick welder for, right? I wonder if JB Weld would hold up....
mine broke clean off the silencer the night before a group ride so I had to weld it with what I had.. at first sight it really looked like some cast steel considering it felt brittle as it broke easily so I considered using n100 but if I was wrong it could break in the middle of nowhere and the other mounts could’ve broken off with it so I used the strongest filler I had(ss304) and welded the sucker the best I can and it held up for a long time on 10k+ miles of travel.. the n99 was on my buddy’s workshop and had to use stick but in my opinion it held up because he only broke one mounting tab(mine were 2, upper and lower) so it didn’t really need some strong weld to hold it.. in my opinion a mild steel filler can hold er especially if it just cracked and not broken off then you could spray some engine enamel or hi temp paint after but I recommend pre heating the metal before welding unknown alloys just to be sure.. heck u can even solder or as you said JB Weld the crack if you have plans on installing aftermarket exhaust anyways..

 

[Ares]

Time to decat! It's a sign.