KTM 790/890 Resolving The Camshaft Issues!

[@leecunningham9759]

I have 46k miles on my 2020 790 never had valve clearances checked and pulls like a train. Always sounded like a bag of nails. Don’t worry and ride it.

[@Libroer]

May I suggest that you record this first take as you do, rewatch it and take notes, organize your thoughts, and redo it more concisely? Useful info, thanks for sharing. Subscribing.

[@cliftonsr]

Awesome and I appreciate your helpful advice.

[@rideinnl]

6:32 that’s a great idea to check the oil sensor and the filter, but the oil flow should be coming from the top? I imagine all the debris should be inside the filter.

[@johnDukemaster]

Well I did! Mine is a Duke, 2020 model and had the screen. And it was clean. Thank you for the good advice.

[@donnyjackson1908]

This engine design isnt one to last 100k miles. The cam lobes are very aggressive and they ride on a finger follower. This is 1960s technology. It works and makes tons of power, but wear is excepted much earlier than a shim on bucket setup. Clean oil with a high shear rate (HTHS) is the only way to extend cam life. With perfect care and lubrication I don’t think this design could go more than 40-50k miles without a cam replacement. There is simply too much valve-train pressure due to the lobe design and spring pressure rates.

[@johnDukemaster]

You are absolutely right Clifton. The internet/keyboard warriors puts fuel on the fire. The issue is real, but not in those numbers one might beleive reading comments. That aside, this is a good tip! Really good thinking. Thank you for that! I will have a look at my 790 Duke 2020 with 26 000km later today. I'll be back!

[@rafaellastracom6411]

The solution, apart from accurate machining, is the use of a smaller diameter gear wheel driving the oil pump to generate 20% greater flow rate across the rpm range. The aftermarket should provide said gear with the resultant smaller chain required. You will be rolling in money.

[@rafaellastracom6411]

@@ihateemael You would end up getting less volume of oil to the furthest points from the pumps which are the points in question. Viscosity is not that critical, oil film thickness is and that means volume. It just needs more oil.

[@rafaellastracom6411]

@@ihateemael I agree with your assessment but it is not relevant to this issue, in my opinion. I don´t believe oil film thickness and strength to be the issue. Specifically I believe there is practically no oil reaching the cam. The difference in oil film thickness and strength from one grade to another would not have such dramatic effects. It would account for cams wearing down below specification in, let´s say, 75,000 km instead of 100,000 km. But that is not what we have with these failures. These failures imply practically no oil whatsoever is getting to the critical surfaces. If you supplied sufficient volume of a vegetable grade oil they would still last longer that what we are seeing.

[@troykelso]

Oil and oil pressure don't matter if the passageways aren't machined properly and the oil can't get to where it needs to go.

[@rafaellastracom6411]

@@troykelso That is implied.

[@PadmaDorjee]

Hello Clifton. Ive just ridden back from a dealer having put a deposit down for a 2023 890 Duke R, have I made a huge mistake? I heard these problems were with the Austrian made 790 bikes, i was not aware of the 890 models also having the issue. Should i ask for my money back and buy a street triple or Yamaha MT09 instead? P.S I like your honesty and humility 🏆

[@cliftonsr]

@@PadmaDorjee I have not seen any 2023 and later KTM 890 engines with bad camshaft

[@pepitogrillo8813]

What are the symptoms that the camshafts are damaged, how do you find out about it?

[@cliftonsr]

You'll start losing power and hear excessive noise from the engine, but mostly from pre 2021 models.

[@mrd799]

@@cliftonsr found a cheap 790 duke 2019, i wonder if i replace the cylindre head to a new updated one, would that also fix the too narrow of cam lobe followers? or did the 2019 model not have that problem?, found this one for 5300 euro with only 1250 km on it. But unless i know i can resolve these issues i wont buy it.

[@cliftonsr]

@ it would be good to go, just make sure you get the thimble filter screen also and with the updated cam followers and the camshafts will be the last thing you’ll ever have to worry about.

[@RedRupert64]

If the followers and/or cam lobes were too narrow on the 790s, wouldn't increasing the width of them simply delay the wear problem a little? I've just removed the valve cover of my 2021 890AR, 34k km/21k mi. The lobe on the left intake has markings on the tip (it's the easiest lobe to see). Looks like soft metal deposits smeared on, or the hard shiny surface has begun to wear away. There is a small ridge on the outside of the cam lobe. I can feel it with my thumb nail. It shows up well when photographed because it catches the light. If you'd like to see a pic, please let me know how to get it to you. I don't use FB, but could get someone else to post it there. Today I will check the thimble filter.

[@cliftonsr]

Yes please let me know at [e-mail]

[@queenslander954]

Good test to see if you’ll will have problems in the future is a oil pump pressure test , KTM workshop Manual states 26psi at idle & 50psi at 7000 rpm , so if you are under that with a calibrated gauge then it’s not going to look good for the future longevity of your engine. If KTM argue against that , they are hypocritical because it’s their testing procedure.

[@LouisPhilippeLebouthillier]

Do KTM dealers change/check that small mesh filter upon oil/filter change service?

[@cliftonsr]

If they don't maybe they should start doing so because it is very easy to inspect by unscrewing the oil pressure sensor and looking inside, just a few minutes with the right tools.

[@Libroer]

You have to take the valve cover off so changing it wouldn’t be included in an oil change

[@cliftonsr]

@@Libroer true, you would only be able to inspect the thimble filter for contamination by removing the oil pressure sensor that only takes a few minutes though.

[@RedRupert64]

No, dealers will not check or change the thimble during an oil change because it's far too complicated to get to. One could inspect it via the oil pressure sensor hole, as Clifton has shown us.

[@ChocoBelge]

I can’t understand that with one oilfilter and two standard screens, which no other engine other than KTM has, there is still a need for a filter on top to avoid clogging the oiljets of the camshafts. I sold my 2021 KTM 790S with 42000 km on it and looked at the camshafts and you could see some traces on them, but no damage. I think that KTM doesn’t have any idea how to really resolve this problem because it’s not happening on every bike. It’s a shame because I love the bike and changed it for a Yamaha instead. My warranty period was over and my confidence gone after all that bad news. Waiting until your engine breaks and then repair it even under warranty isn’t a good service. A recall or at least a check up on their costs would have given me more faith, but nope. 👎

[@gabriellsti193]

Hi, your video is very interesting.. Do you know precisly the period and wich model is touch by this technical issues.. Thanks from France

[@cliftonsr]

@@gabriellsti193 here in the US only seeing the 2019 and occasionally 2020’s that didn’t have the filter screen in the head, that’s the report I am also getting from the KTM WORLD parts distribution out of Georgia US.

[@victorgonza4528]

The oil feed to the camshaft is no good , cross drilling for the oil jets is off .

[@TheOliveradams]

Do you know if there are camshaft problems with the Duke 890R (2023) ?

[@cliftonsr]

So far I haven't found anyone who can prove it to me or that I have seen them take off a camshaft and say here is the 890R Duke and here is the bad cam. So again I haven't seen any and I have talked to KTM World Parts and to other qualified KTM dealer techs and they tell me the same, that they have only seen the 790/890 from 2019 to 2021 years with this problem.

[@kennymiller8973]

Sit and watch your video, don't skip forward. Then edit it. If you're willing to do this work, you will have an audience.

[@toddv9210]

If only it was just an oil supply problem, but it's not...

[@cliftonsr]

true to that for the early model 790s also had too narrow of cam lobe followers that ate into the cam lobes that were made wider on the later model 790s and 890s that fixed that problem.

[@RedRupert64]

Wouldn't that mod just delay the problem?

[@toddv9210]

@@RedRupert64 Some bikes may actually suffer from a clogged jet, in that case it may keep them going a lot longer but the real issue I believe is a design and materials flaw. The profile of the cam lobe is to aggressive for the materials used. With a gente lobe they may last forever with the cam/followers used but it's far from gentle.

[@RedRupert64]

@@toddv9210 You may well be right. They're certainly an odd shape! If you are, I'd consider replacing the cams at 35k km intervals. They're not that expensive, and I'd do the work myself.

[@RedRupert64]

@@toddv9210 I've been thinking more about this. The mesh should be finer than the jet, so anything that gets through the mesh should not block the jet. It would be extremely unlikely that several small particles could get through the mesh, then stick together, so as to block the jet. Looking at the cam lobes on the 990 SM, they also appear to be radically shaped, but they are far wider and push again a bucket with a large surface area, so plenty of load distribution.