Front Fork Rebuild: Oil Seals and Oil - KTM Duke 390 125 250 200

At some point you may need to replace the oil seals or change the oil in the front forks of your KTM Duke 390 125 200 250. This requires a rebuild of the front forks. Note that this is not a full service of the front forks as that requires rebuilding the cartridges.
I've blown one of the fork seals and I have a small oil leak so I need to strip the forks down and install new seals. This also allows me to change the fork oil which since it still has the original oil is overdue for changing (although I can find no service interval specified for the fork oil).
Remember not to overheat the fork leg as this can weaken it, so a temperature gauge will be on my list of tools to buy, because I will be doing this again as I continue to practice my wheelies.
Fork Oil 450 ml SAE 4 per fork leg
Torque values:
Cartridge screw 25 Nm
Screw cap on outer tube 30 Nm
Screw Top Triple Clamp 15 Nm
Screw Bottom Triple Clamp 12 Nm
Instagram: / moto_mirius
Subscribe to keep up to date with the regular content: bit.ly/2UWwY90
___
Upgrade Links - Moto Mirius
www.motomirius...
KTM Duke 390 Servicing - Moto Mirius
www.motomirius...
Watch KTM Duke 390 Servicing Videos on KZbin
• KTM Duke 390 Service a...
KTM Duke 390 Upgrades - Moto Mirius
www.motomirius...
____
Follow me here:
Instagram: / moto_mirius
Facebook: / motomirius
Website: www.moto.mirius...
___
Music provided by Epidemic Sound: www.epidemicso...
___
Logo: bit.ly/2Zau67P
#RokONSquad #MotoMirius #KTM390
moto mirius,RokONSquad,rok bagoros parts,ktm 390,ktm motorcycle,ktm,
ktm duke 390,390 KTM Duke,ktm duke,duke 390,390 duke,duke 390 mods, 390 duke mods, duke 390 modified
2017 ktm duke 390,ktm duke 390 2017,2017 duke 390,390 duke 2017,duke 390 2017,2017 ktm duke,2017 duke 390 modified,2017 duke 390 mods,
2018 ktm duke 390,ktm duke 390 2018,2018 duke 390,390 duke 2018,duke 390 2018,2018 ktm duke,2018 duke 390 modified,2018 duke 390 mods,
2019 ktm duke 390,ktm duke 390 2019,2019 duke 390,390 duke 2019,duke 390 2019,2019 ktm duke,2019 duke 390 modified,2019 duke 390 mods,
2020 ktm duke 390,ktm duke 390 2020,2020 duke 390,390 duke 2020,duke 390 2020,2020 ktm duke,2020 duke 390 modified,2020 duke 390 mods,
ktm rc 390,ktm rc,ktm,rc 390,390 rc,rc 390 mods, 390 KTM rc
2017 ktm rc 390,2017 ktm rc,2017 ktm,2017 rc 390,2017 390 rc,2017 rc 390 mods,2017 390 KTM rc,ktm rc 390 2017,ktm rc 2017,rc 390 2017,390 rc 2017,rc 390 mods 2017, 390 KTM rc 2017
ktm duke 125,125 KTM Duke,duke 125,125 duke,duke 125 mods, 125 duke mods, duke 125 modified
ktm duke 250,250 KTM Duke,duke 250,250 duke,duke 250 mods, 250 duke mods, duke 250 modified
ktm duke 200,200 KTM Duke,duke 200,200 duke,duke 200 mods, 200 duke mods, duke 200 modified

[@steelhawthorne]

Hi! I read the 2019 repair manual to inform myself on this process but seeing you do it made the process concrete rather than abstruse--thanks!

[@MotoMirius]

So now I expect you to be able to do it flawlessly! :)

[@steelhawthorne]

Question: After 3,300 miles and my pandemic weight gain I am changing my fork oil to the next higher viscosity index. What's the rule of thumb? Change seals each time after disassembly? After X mileage? When they fail only? What's the OEM part number for the kit you used? Thanks!

[@MotoMirius]

@@steelhawthorne So long as you are careful not to damage the seals they can be used more than once - best to invest in some form of seal protector if you plan to experiment this way and change them when they need it. The kit is 90101000010

[@steelhawthorne]

@@MotoMirius The Duke’s repair manual says to “Always change the dust boot, seal ring, lock ring, support ring .” That’s four parts, however, the KTM parts schematics only shows three, o dust boot o shaft seal o guide bushing Wtf? I’m confused. The names the manual uses and the schematics uses are different. But, From what I can discern, I think, I think ktm manual means: Yea yea, change these parts in a perfect world, and what are those part numbers? we don’t know. I don’t see them listed in the schematics. Please clue me in. Im going to follow the manual’s advice. But at this point all I think I need are the seal rings. I want to buy a clue for 100, Bob. :-)

[@steelhawthorne]

@@MotoMirius (1.) Seal protector? What’s the logic? You mean those Velcro wraparounds for dirt bikes? (2.) Anyway, I’m collecting the tools needed for the fork oil service, and I just received a new Motion Pro 43 mm seal driver[1], however, it came with a nick on the _bottom/driver_ side. This has made a protrusion on the outer diameter of the tool about a 0.5 - 1 mm tall, which might contact the inner diameter of the fork tube and cause an issue. Question, I don’t want to exchange the tool, I’d rather not file it down, because I think it shouldn’t affect anything. But since I haven’t this specific experience I want your opinion. If I have to file it, fine. I had to wait a month for this to be available. [1] You can view the tool at RevZilla under SKU: 913336

[@niklaswilk4964]

I have done a fork service today on my Duke 390 2017, probably the first fork service erver done on this bike. Everything was perfectly fine and as explained as in the video. In addition with your explanation it is extremely helpful. Thank you very much! Greetings from germany. 🙂🙏

[@MotoMirius]

Nice work! Thanks and well done!

[@georgebrci5610]

I was just searching some info for rebuilding my forks on a duke 390 gen 2. Thanks again. I almost looked up every single duke 390 video you posted and, being a 6 month rider, your videos helped me a lot to make my own repairs and upgrades. Very useful👌👍

[@MotoMirius]

Glad I could help! Once you've learnt how forks come apart, it's a lifetime skill to have. Skäl David

[@sergiocastillo3089]

@MotoMirius What's the name of the tool you use to put inside one of the bushings?? The black one that is hit by the one divided in two.

[@tobymcnicol922]

Another extremely useful vid - as I've come to expect! I have a leaky fork seal, which is going on this winter's maintainance list. Thanks for demystifying the process. 👍

[@MotoMirius]

good luck with that. It's a simple enough process with these open cartridge forks.

[@tobymcnicol922]

@@MotoMirius I was wondering about slightly thicker oil too. Do you think I'd notice much difference if I went for 5w over fresh 4w given that its probably 8 year old oil in there at present?

[@MotoMirius]

@@tobymcnicol922 probably not, but unless you have a specific reason to change oil weight I'd leave it alone - cartridge type forks have very small oil passageways so thicker oils. especially when cold won't flow as well - it's not like the old days when a thicker oil was just damping the spring.

[@Funny_as_Duck]

What would I do without this man🙏🏼

[@MotoMirius]

Thanks, much appreciated! Skäl David

[@wrap-itsolutions2387]

Thanks for taking the time to make this video. My son just got a 125 Duke that needs a bit of love.

[@MotoMirius]

Thanks and good luck with that!

[@RC7MASTER]

Thank you brother for this awesome tutorial for beginners like me in Ktm... Ride safe and God bless.. Always support here im from the Philippines 🧡🧡🧡🇵🇭

[@MotoMirius]

Thank you too 👍

[@TheJWC56RSA]

Thanks David! I got a leaky seal up front on my Gen 2 390. I took it apart without much capturing the process... and it was quite a lot of figuring out how to put everything back as my forks were not so "conventional". The KTM OEM seals, sold as a pair were expensive so I got a set from a 3rd party - 5000 km further and it is still 100%! Regards!

[@MotoMirius]

Thanks. I almost bought third party seals, you can get everything in the kit for less than the dealer charges, but I thought I'd go OEM for the video! Skäl David

[@dadomoto]

Excellent. Thanks to your detailed videos, my 390 has been home serviced for over a year and my wallet is thicker.. now if we could only get a valve clearance video..

[@MotoMirius]

Valve clearance will be coming but its going to be part of a larger job so I need to get other jobs out of the way first! Skäl David

[@federicocao574]

Yeah valve clearance and shim replacement, please!

[@tobymcnicol922]

@@federicocao574 There's a good vid on this by Ari Henning from when he was at MC Garage.

[@moosen8024]

Thank you good sir! An outstanding video for the ktm duke 390 community 👏 you helped me understand the process 🙏 i am grateful for your breakdown.

[@MotoMirius]

You are very welcome, thank you.

[@BishalTamrakar]

Thank you for your video, I managed to repair the oil seal on duke 390. Kudos!!!

[@MotoMirius]

Excellent!, well done!

[@springy-2112]

David my brother , another excellent video that's going to help many bikers do their own maintenance. Assuming their forks are the wrong way up ! my head was destroyed half way through trying to figure what's up and down so it must have been huge fun for you actually getting the seals in correctly.. I wonder What's next , inside out tyres? I'm too old (and ignorant) for all this modern trickery ! Cheers buddy . Have a great weekend . Peace and love 👍🏻☮❤

[@MotoMirius]

Cheers Springy. Fear of the USD kept me away from them until I had to. Now I realise that they are jus the same as the older forks - now proper cartridge forks... well, that's a whole different game! Do fancy having a go at stripping down DRZ forks, if only I hadn't sold it! Hope you are doing well! Skäl David

[@dhruvsingh2666]

Hey it’s me again and guess what I changed my oil by my self. U really nice guide. ❤️from India

[@MotoMirius]

Awesome! Well done!

[@dhruvsingh2666]

Do you have any idea about price of inner tube.

[@MotoMirius]

@@dhruvsingh2666 officially only available from your dealer - or buy another leg second hand.

[@LondonCarnaval]

Excellent video and very well presented. Thank you 👍👍👍👏👏👏 🤗 ✌❤☘

[@MotoMirius]

Thanks, much appreciated Skäl David

[@TeamWeberRacing]

Thanks to you I did this on my own!

[@MotoMirius]

That's awesome! Well done!

[@Near2Future]

When it's in the clamp. Make sure to loosen the top triple tree bolt. As that puts pressure on that cap, which can damage it. So loosen that first before loosening or tightening the cap.

[@user-ke7dg7sy7t]

Top 3 tree bolt? Where is that

[@Near2Future]

@@user-ke7dg7sy7t I was refering to this 2:30. See how there is 2 camps on the fork one with 2 bolts, in the lower one & one bolt at the top. Well, before you slacking off / tighten the main fork cap. You must loosen the top triple clap (the one bolt at the top).

[@rlrjchannel2673]

Sir this video is very helpful thanks sir just have one request changing oil seal in new duke 390 adventure👍👍

[@MotoMirius]

Thanks. I don’t have one and not sure they sell them here yet. Process is likely to be much the same.

[@mnz7247]

Love your contents, really helpful and funny

[@MotoMirius]

Glad you like them! Thanks

[@steelhawthorne]

David, I have a video idea, it’s self serving I admit, but there’s nothing worthwhile, intelligent or specific to this generation Duke: “How to Remove the Headlight.” My case is specific. I hit a pothole and damaged the upper plastic retaining clip (“KTM bush Part # 93014024100”), a $0.99 part. Headlight attachment points are triangled, with 2 at bottom, 1 at top. The jolt snapped the clip, and the headlight flops forward. The manual doesn’t cover headlight job. I can not discern how to free the bottom attachments? I’ve removed the top case/plastic holster/black screw. I see 2 side, case hex screws I might try. I’ll solve it, eventually, but if I need help someone else certainly will in future.

[@MotoMirius]

I have covered headlight removal within a video, but I have been asked before so I might make a specific video - short answer, yes you need to remove the two side screws as well.

[@federicocao574]

Awesome vid, Now can I finally service my Vitpilen 401 on my own. (Except for the engine) ;)

[@MotoMirius]

That is great to hear. Good luck with that.

[@fukpolitics]

David, what size is the bolt head at the bottom of the fork? It seems to be a 7mm which is an odd size Allan key that I don't have (I have 6 and 8 which is part of any standard set)so I can't get the bolt out. However, I did manage to get the cartridge out. I just can't remove the outer tube from the inner tube

[@MotoMirius]

Yes it’s a 7. I guess you are US based if your standard sets don’t include a 7. Bolt only holds the cartridge in place. Tubes are held together by the circling under the dust seal.

[@ezekielgskeen8607]

Awesome! Awesome Video Mirius! Love your video's, no disrespect! But! you are the Sh#t! Stay amazing Sir, Salute to real you tube content makers like your self.

[@MotoMirius]

I appreciate that!

[@taneredable]

Thank you very much for this great video, which brand of oil seal did you use?

[@MotoMirius]

Thanks, the kit is all KTM.

[@dgsdavid8623]

Can youy make a video showing how to serviçe the rear suspencion?

[@MotoMirius]

Thanks for the suggestion. It is on the list, although the rear shock unit like most stock units isn't serviceable. I will see what I can do on that one. Skäl David

[@RominYadav]

So helpful

[@MotoMirius]

Glad you think so!

[@ajfryer]

Fantastic Video, Shit scared of doing this myself but think with video i will be able too so thank you. Would this be the same process for a 2018 KTM duke 690? Sure it will but just checking before i start. Thanks again and keep up the great vids!! :)

[@MotoMirius]

Without knowing exactly what was fitted to the 2019 690, the answer is probably. The vast majority of entry level bikes all have similar designs of fork - there are some differences but essentially the principles are the same. As the bikes get more expensive then cartridges become more common - as we see here, but even so it doesn't change too much except the need to properly bleed the cartridge. As you move more high end, the more surgical it becomes, so the less it's something you should be doing in your shed and the like it should be done in an operating theatre because of the importance of keeping everything clean etc - and a top end suspension workshop is much like a formula 1 workshop where it's all white tiles, exact measurements and perfectly clean working areas - but the principles don't change as much as you might expect.

[@shabeer1415]

Great video as alwayd, thank you. One more thing would you recomend using 7w oil instead of 4w for bad roads.

[@MotoMirius]

No, I would recommend using the stock oil. Heavier weight oils do not always flow properly through the small holes. If you are riding on poor roads then you need to adapt your riding to suit and not rely on the suspension to absorb the impacts. Choice of route and use of the throttle make a big difference.

[@shabeer1415]

@@MotoMirius thank you for replying, I do appreciate that you are spending your time to reply to our queries, Yes I will stick to the stock oil.

[@sergiocastillo3089]

@MotoMirius What's the name of the tool you use to put inside one of the bushings?? The black one that is hit by the one divided in two.

[@MotoMirius]

Sounds like the fork seal driver? They come in different sizes and designs. The black one is part of the driver.

[@chandrashekharhandique8112]

Really appreciate you SIR ❤️

[@MotoMirius]

Thanks!

[@scottlloyd1938]

Hi mate, picked up a 125 duke and looking to change the fork seals… what tool do I need to undo the bottom? Is it a 7mm Allen key? Many thanks

[@MotoMirius]

Hi, it is an allen key. Personally I don't recommend buying individual allen keys (or spanners) in common sizes - much cheaper in the long run to buy a set. But yes it is a 7mm

[@FIAlex93]

Hi Moto Mirius, thanks for you great videos Some knob tried to steal my duke 390 and broke the steering lock in the process. How difficult would it be to change the top triple clamp yourself? Would you recommend doing it yourself?

[@MotoMirius]

Removing the triple clamp is a fairly straightforward process that you can do if you have some experience of working on the bike. Lock replacement is often the hardest part as they are often fitted with anti theft bolts - never really understood that given how easy it is to break the lock itself.

[@cmcravo]

You should refer in your videos that its the exact same for the husqvarna 401 and 125, i use lots of your videos as reference

[@MotoMirius]

Thanks, yes, I do need to do that - as you will see I've fitted 401 forks in my latest video

[@gabrielrandrade]

Hello sr!!! Congratulations for the video... awesome... can i ask u something??? Do u know if its possible to increase the preload for the front suspension? I know this bike don't have it for the front suspension... but maybe i can put a spacer... a washer... between the spring and the base... to increase the tension... that is possible??? Txs

[@MotoMirius]

Thanks. You could probably do something but I'd suggest looking to see if you can get the adjustable fork legs from the Husqvarna 401 and use those instead as they come with the WP open cartridge instead of the base version in the Duke

[@Kuper133]

Можно вопрос не по теме видео? У вас есть видео как прменять топливный фильтр. На других каналах видел там снимают бак. Без снятия бака нельзя заменить фильтр?

[@MotoMirius]

It should be possible to replace the fuel filter but you will probably need to unbolt the tank at the rear to gain some room. Have a look under the side of the tank and see how much room you have for your hands.

[@Kuper133]

@@MotoMirius Everything is clear, thank you very much! Is it better to drain the gasoline from the tank?

[@MotoMirius]

@@Kuper133 Not necessary.

[@itzlizardking8704]

No puedo quitar el tornillo de la parte de abajo de la barra, se gira con todo y la tapa superior junto con el resorte, todo gira al mismo tiempo aunque lo atrape con la prensa. Que esta pasando?

[@MotoMirius]

Esto es muy común: está intentando deshacer un perno; si está apretado en la rosca en la que se atornilla (y no hay nada que mantenga esa rosca en su lugar), entonces las partes internas girarán con el perno, como cualquier tuerca y perno. Una pistola de impacto puede ayudar, ya que puede soltar el perno. O tienes que separarlo de la parte superior e intentar mantener las partes internas en su lugar, lo cual puede resultar difícil.

[@jimmycut3385]

Hi how do i know when i need to change the fork oil? And do u know how to make the duke 125 sound better and not louder? Thanks

[@MotoMirius]

Hi, fork oil doesn't have a specific service interval, so normally when you get a leak on a fork seal or when the forks stop working as they should and you need to overhaul them. It will depend on which model of 125, but generally you can't make it sound better without also making it louder (or at least appear to be louder). A shorter end can will tend to make it sound a deeper note, but it will be louder.

[@GhostMotoDiaries]

hey mirius. so mine has a leak and I checked there are 3 parts to the fork seal... I only need the middle part right?

[@MotoMirius]

It depends on why the seal was damaged. Normally its a result of dirt getting past the dust seal - even if you bottom out the forks the damage to the oil seals is normally a result of that forcing dirt that got past the dust seal into the oil seal. Slide bearings need changing when they need changing. It's good practice to also change the dust seal but...

[@mafiaboy4925]

Whats the difference between orange and black sealing ?

[@MotoMirius]

If you are referring to the dust seal, then noting, it is just a dust seal - but as with everything bike related, buying cheap is rarely a good idea.

[@mr.maxrev6435]

Those bottoms can be open and swapped to different lower tubes?

[@MotoMirius]

It should be possible to remove the bottoms and swap, yes - it goes without saying that you would be limited to the same size tubes.

[@mr.maxrev6435]

@@MotoMirius right thanks

[@tamarapristupa1703]

Mirius, Excellent videos. I ask you from Argentina, is it possible to repair the rear monoshock? i have a duke 390 2016.

[@MotoMirius]

Thanks. Technically yes, but it's not built to be modified so it might be something that can be done where you are - but here it is too expensive to do and cheaper to buy a replacement

[@hakyhas8220]

TKS

[@rajpriyam6640]

Is 1st gen RC outer pipe cover(fork) same as Duke?

[@MotoMirius]

As far as I'm aware they are the same unit - but I've not had them side to side. I know the Duke top clamp fits the RC so it's likely they are the same.

[@rajpriyam6640]

@@MotoMirius thanks for the info sir. Appreciated.

[@azharmohammad3518]

I had recently changed both the oil seal on my duke 390 at the service center. what happened is they got stiff and there is no compression and rebound. The mechanic at the service center couldn't find an answer to this. What count be the issue?

[@MotoMirius]

If there was no compression or rebound before they went in then there is likely damage in the cartridge and it will need rebuilding or replacement, or the forks are bent and need replacing. If this only happened after the seals were changed then they need to come apart again - it might just be they were not aligned properly or it might be something inside the forks - over the internet we can only guess. It is very simple just to take the forks out and check each one to see if just one has an issue.

[@abhilasha6876]

❤❤❤❤❤

[@shanefurlong6509]

Hi Dave, just done my fork seals on a ktm duke 390 gen2, all went well but when I push them off the ground individually, one feels springer than the other, is one side damping and one side rebound?? The only thing i noticed was one cartridge has its weep hole at the bottom and the other has it at the top! Your videos are very helpful! 👍🏻

[@MotoMirius]

Hi Shane, the forks on the bigger Dukes are split but I don't beleive these are - you would have seen a difference between them when you had them apart.

[@shanefurlong6509]

@@MotoMirius no difference inside only the weep hole in the cartridge, one under spring on one side the other at bottom of cartridge, everything looks good inside, new oil seals and dust covers, new 5w oil, bike only has 20k miles, just one seems to rebound quicker than the other??

[@ezekielgskeen8607]

One more thing David! would the measure of fork oil be the same, for my Duke 125 2018? Thanks!

[@MotoMirius]

Yes, I would expect similar - the fork externals are the same, I would guess the internal springing might be different - they have a different part number but all of the external parts of the forks are the same.

[@richirichxxx8940]

Which shock absorber oil should I use? 5w 10 w?

[@MotoMirius]

As per the video description, KTM recommend 4w. Since it's a cartridge you should be careful about using heavier weight oils as they will not flow as well through any micro passages in the cartridge.

[@pabloleon1241]

Great video, thank you. I bought two pairs of seals (one for each side) and still waiting for a leak to perform their maintenance. I have two questions: a) what is the torque to assemble the bolt on the top and the bottom of the fork? (not the clamps) and b) my friends already made this service on their bikes, and they use a different fork oil. They said is better and feel a tighter ride and better control. What is your opinion about it? I think the oil is not too thin than the one from motorex. Thanks again.

[@MotoMirius]

All the torque values are in the video description. Some people choose different weight oils - thicker (higher numbers) makes the fork slower on the damping - tighter would require a stronger spring. But you have to be a bit careful with big changes to oil weight in cartridge forks because the thicker oils don't cope so well with the oil passages. Typically these are changes made by heavier riders or those wanting to race, but it's always a compromise because a tighter fork can have less grip on rougher surfaces. There is no one answer that is right for every rider in the world which is why there are suspension shops who modify suspension to individual riders.

[@pabloleon1241]

@@MotoMirius thank you for your answer, now is clear to me that I must use the same fork oil as factory designed. I appreciate your experience on this matter. Keep going..!

[@netanelgabay4554]

Thanks! Does any 43mm ringer fork seal driver fit for this forks?

[@MotoMirius]

They are standard seals so I would think so.

[@yannisgiokas]

Hi I did all the procedure as you described and I also had the ktm instructions. I even bought the ktm's fork clamp vice adapter. When I mounted everything up and sat on the bike I compressed the forks down a few times and I can hear a scraping noise from the top of the forks as if something scrapes metal to metal. Do you have any idea what might have gone wrong? I can't think anything in the procedure. Oh the only thing is I haven't yet torqued the top cap. But I have tightened it by hand as far as I could. I thought I would torque it when mounted on the bike cause the clamp would let thehousing rotate when i tried to torque it at the workbench. Thanks.

[@MotoMirius]

Hi, yes, torque when it's held in the clamp is fine - as you say, you need to hold the tube so you can torque it. There is no obvious reason why it would do that. Did you try to compress them before fitting? Should be easy enough to spot which is causing the issue and then just open it up again and spot what is going on. Good luck with that.

[@yannisgiokas]

@@MotoMirius yes I did. I did everything by the book. According to ktm manual. It sounds from both of them. Any way because I was bored to dismantle everything again, I decided I will drive it and see what happens! 😀 I will drive it to work tomorrow and let you know. Thanks any wayfor taking the time to do all these videos and help us out!

[@MotoMirius]

Good luck with it. I'm sure you did everything right but something must be a bit adrift, fingers crossed! @@yannisgiokas

[@yannisgiokas]

after 2 days of commuting to work and back now everything is fine!Good as new and a tighter feeling at the front. Thanks again for all your help!@@MotoMirius

[@MotoMirius]

Thanks, but well done to you! @@yannisgiokas

[@willyangabrigo1174]

Hi Sir, may i ask if the fork outer tubes fr duke 390 is the sane with the adv, my fork outer tube is dented, wondering if i can install it to my adv, n still use the inner tube n caetridge fr my adv

[@MotoMirius]

I would think it unlikely, the Adventure probably a longer travel.

[@danielplotado6991]

Hi my friend.. i have concerns to ask... My front fork keep leaking and leaking... I change new oil seal .. and leak again and change to new again and leak again.. What the problem? KTM DUKE 390

[@MotoMirius]

If the fork keeps leaking then it suggests that the problem is not the seal. Most likely there is damage to the fork leg or the stanchion.

[@chintankonamme9107]

​@@MotoMiriusMy Duke 200 has the same issue. I've changed the fork oil seals multiple times over the years and within 300-400 kms, the seals break give up. How do we find if a fork leg or stanchion is damaged? Could you please suggest as to what are the particulars to look at?

[@MotoMirius]

@@chintankonamme9107 most likely either the stanchoin is damaged - you can see this by looking closely at it. Or you ride in dirty conditions and don't clean the forks often enough. Or you are buying fake seals not made correctly. Close visual inspection and making sure there is no damage and nothing is bent is all you need to do

[@davidjsherwood]

do you know if there is a fork cartridge upgrade kit for our bikes?

[@MotoMirius]

One of the more common ones is www.andreanigroup.com/prodotti/moto/105%7CKT7E/?CARTUCCIA+KTM+DUKE+390+2017-+-+EVO-R+

[@rajeshranganath.k6927]

Hi sir. Im confused, need some help!! I own a 2016 Rc 390 (Gen 1). 20k-ODO reading. Ridden mostly on good roads ( cautiously on bad roads) I haven't had the requirement to change the seals or oil on front forks since purchase. Now im having lots for frork-dive when im braking. Can you suggest me the solution?? My doubts.....:- 1:- Would just a general fork oil change do the job (motul 4w) ?? ( As 6-year-old oil would have lost it's viscosity, is the front Dive-in because of that??) 2:- Online many people are telling to go for Motul factory line 5w to add extra firmness and tackle the dive in. ( Im worried about the ride quality). 3:- A friend of mine suggested me to get the springs inside the fork changed and go for regular 4w oil. Is that required?? If so would gen 2 springs fit on my gen 1 rc.?? Totally confused.

[@MotoMirius]

On an eight year old bike, if you have experienced a relatively sudden change in the way the forks are operating then I would suggest that they are serviced. The oil may have degraded or the springs may have started to set in a compressed state - this will be checked as part of the service. If you were happy with way the forks were operating (and it sounds as though you were) then I would have them rebuilt with the stock oil weight that they previously used. So option 3 sounds about right ie put the forks back the state that you were happy with before.

[@rajeshranganath.k6927]

@@MotoMirius Thankyou sir. would the spring from Gen2 forks fit the Gen1 forks. Cz the ktm service center says the Gen1 parts are out of stock.

[@MotoMirius]

@@rajeshranganath.k6927 I don't think that will work as the fork internals appear different. You may need to go for an aftermarket kit such as Hyperpro.

[@rajeshranganath.k6927]

​​@@MotoMiriushi sir to counter the Front-dive-in, i finally managed to get OEM fork springs(Gen-1 rc 390). Since Motorex-4w isn't available here what are better or equivalent options ?? Maxima 5w, Maxima 7w, Motorex-5w, Motul -5w & 7.5w are available here. Can you suggest me the equivalent of better one for Street usage ?? I don't mind the ride being 10-15% stiffer with significantly improved handling.

[@MotoMirius]

@@rajeshranganath.k6927 Check out the manufacturer recommendations. I've found limited information on the RC but Motul appear to recommend 5w

[@jagathhettiarachchi9373]

David, my savior, I'm interested in that bike stand and wondering how did you get the bike on that stand? what is the name of it? can you help?

[@MotoMirius]

The stand I use for this sort of work is by Abba, and I was using the add on front lift arm, though they do make a sky lift instead. Their stands are universal with fitting kits for different bikes. The local tyre fitters to me have one on a lift that they use to remove wheels from all their customer bikes. abbastands.co.uk/

[@jagathhettiarachchi9373]

@@MotoMirius Thanks david.

[@dominic9279]

I don't suppose you've got the measurements of the oil seal?

[@MotoMirius]

No sorry, didn't take them. Thought I kept the old ones, but can't find them.

[@chroniclepro4435]

What about if you don't have a heat gun?

[@MotoMirius]

I'm sure you can find a source of indirect heat to achieve a similar effect. The idea is to have a gentle method that doesn't risk damage to the tube.

[@erwinfalcotelo2882]

Hi whats the size of oul seal you use?

[@MotoMirius]

I haven't measured them. There appears to be some variation according to year. Next set I will check the dimensions

[@papshopmotovlog2780]

Nice,👌👌👌

[@MotoMirius]

Thanks 😊 Skäl David

[@jiaqianglu4994]

Are those original cartridges ???

[@MotoMirius]

Yes, everything is stock. WP is a KTM sister company.

[@jiaqianglu4994]

@@MotoMirius May I know which year is it? Because I never see this model before 🤣🤣🤣

[@MotoMirius]

@@jiaqianglu4994 These are the forks fitted from 2017 - 2023

[@jiaqianglu4994]

@@MotoMirius I think it can upgrade to Apex pro 6500

[@MotoMirius]

@@jiaqianglu4994 Yes, you are right - I've been waiting for them to launch these and looks like I didn't even notice. Thanks for that. Not sure I need them enough to pay the price though!

[@yaseenyaseenpungganur6138]

💯💯👍

[@Usiris23]

Wearing my headphones and gotta say I’m not enjoying the sounds while your pumping the forks haha

[@pradeepkummu1917]

👌👌👌👌👌👌❤❤❤❤❤👍👍👍👍

[@auliarakhman7002]

How many oil in a both of tube?

[@MotoMirius]

450 ml per tube, so 900ml in both

[@jonfyfazan]

👏👍👌🇳🇴

[@MotoMirius]

Thanks