Any wisdom on KTM 790/890 Cam wear problems?

[Roadhawg011]

There seem to be a lot of incidences of early cam wear (intake lobes mostly) on the KTM LC8c engine (parallel twin 790 and 890cc). Often under 10k kms.
It seems to be much more common in the ADV bikes using this engine and not the Duke. The ADV is tuned for more low end torque and the Duke for more top end, and use different cam profiles as well. It seems the opening of the valves is very aggressive on the ADV cam profile and maybe this is 1 cause of the issue.

I'm just wondering if there is any potential of oil playing a roll here? The manufacturer recommends full synth 10w50 Jaso MA2. (Motorex PowerSynt 4t usually used)

Lots of theories floating around the web of course.
This guy took pics, the lobes still felt smooth so put them back in and carried on (14 500miles)

This one was 20k kms

 

[Trav]

Not just this engine, many engines have had similar problems.I had a brand new Honda VF1100C (V65 Magna) that did this, it comes from improper break in by the dealer, by the time the customer got the machine it was too late. The fix was replace the cams and slippers, lube them well with a break in lube and run it at 2500 rpm for 20 min then change the oil. Using a higher zinc oil or zinc additive helps, at 100K the cams were still like new.

 

[Roadhawg011]

Not just this engine, many engines have had similar problems.I had a brand new Honda VF1100C (V65 Magna) that did this, it comes from improper break in by the dealer, by the time the customer got the machine it was too late. The fix was replace the cams and slippers, lube them well with a break in lube and run it at 2500 rpm for 20 min then change the oil. Using a higher zinc oil or zinc additive helps, at 100K the cams were still like new.

I also thought zinc (or low zinc) might be the issue. What is the normal friction modifier additive that can't be put in bike oils due to the wet clutch?

 

[Cujet]

As always, a robust oil is required when there are no roller followers. Remember that viscosity is the primary way oil protects the parts. Additives provide protection when viscosity can't do the job.

The idea that we can use an oil that is known to rapidly shear down to a 5 viscosity is in error.

I suggest M1, 15W-50 or 20W-50 V-Twin oil, along with frequent oil changes.

 

[Roadhawg011]

I'm also asking because I just bought a Norden 901 with the same motor as the 890.

I have tried to do the 1000km "run in" fairly gently but the urge to wheelie overcame me once or twice. Otherwise tried to do fairly smoth runs up the gears, and kept it under 6500rpm mostly.

I also work in the oil industry but don't have much experience with bike oils besides owning a few 1x90 ktm's Always used 10w50 or 10w60 Motorex full synth in them and they ran great.

 

[tmorris1]

I doubt it has to do with break in. Looks like a defective parts to me. No oil is going to cause that without some other contributing factor.

You aren't the only one with this problem according to google.

 

[Cujet]

I doubt it has to do with break in. Looks like a defective parts to me. No oil is going to cause that without some other contributing factor.

You aren't the only one with this problem according to google.

I was going to say the same. We could test the hardness to ensure that aspect is adequate.

However, I'd state that adequate viscosity will prevent metal to metal contact and even soft cam lobes and followers will live a long time with proper care. Aircraft engines use straight 50 or even 60 viscosity oil in an attempt at protecting the crummy cams and lifters.

I wonder if there is some form of oil starvation problem?

 

[userfriendly]

My guess is insufficient oil delivery to the cam lobes.

 

[BornSlippy]

Must be coming out of the same factory as the HEMI cams.

 

[tmorris1]

Must be coming out of the same factory as the HEMI cams.

Or the Ford 7.3 line. My guess is cheap metal or insufficient hardening of the metal

 

[twX]

The oil at the cams experiences the highest shear rates of anywhere in the engine, and it will usually be in a fully shear-thinned state. Oils with less VII will experience less shear thinning. A 15W- or 20W-50 will retain a higher viscosity and provide better protection to the cams than a 10W-50, even if these oils have the same HTHS. A healthy amount of ZDDP is important as well.

Even with an optimal oil, the cams may still wear excessively on engines that have serious manufacturing defects.

 

[kschachn]

The oil at the cams experiences the highest shear rates of anywhere in the engine, and it will usually be in a fully shear-thinned state. Oils with less VII will experience less shear thinning. A 15W- or 20W-50 will retain a higher viscosity and provide better protection to the cams than a 10W-50, even if these oils have the same HTHS. A healthy amount of ZDDP is important as well.

Even with an optimal oil, the cams may still wear excessively on engines that have serious manufacturing defects.

Look at those pictures after 20K.

 

[paulo57509]

I run M1 V-Twin in the Ducati but no oil will prevent a ("non lo ammettiamo") manufacturing defect. Ducati Desmoquattro engines had a plating problem on the rockers that appeared like that cam lobe. With good reason, it led to paranoid hysteria for a lot of folks. Undetected, it would wipe the cams too.

 

[BusyLittleShop]

I doubt it has to do with break in. Looks like a defective parts to me. No oil is going to cause that without some other contributing factor.

You aren't the only one with this problem according to google.

I agree... not break in nor oil is the culprit...

Some of my customers have said that KTM noted it was down to defective cam shaft treatment/coating...

 

[ZeeOSix]

The super worn cams are at 20 km, so miles are only ~12,600 miles. That's some crazy wear. Some 80s V-4 Hondas ate cams too (mostly surface material loss pitting), and it was a combo of bad cam material/hardening and insufficient oil supply. Once the hardened layer is gone, the wear goes wild. There were updated cams and added oil supply line to the top end to cure it.

Any word from KTM with a TSB or recall? If it's happening to many owners I'd think KTM would know by now and take care of them.

 

[Roadhawg011]

The super worn cams are at 20 km, so miles are only ~12,600 miles. That's some crazy wear. Some 80s V-4 Hondas ate cams too (mostly surface material loss pitting), and it was a combo of bad cam material/hardening and insufficient oil supply. Once the hardened layer is gone, the wear goes wild. There were updated cams and added oil supply line to the top end to cure it.

Any word from KTM with a TSB or recall? If it's happening to many owners I'd think KTM would know by now and take care of them.

KTM tend to be the "Oh wow. That sucks. Good luck!" type. They had issues with the airboxes not sealing properly on the entire 2013-2020 1090/1190/1290 line of bikes. They never resolved it after loads of people had to rebuild topends in less than 30k kms do to dust ingress.

The dust thing is also happening on the 790/890. The airbox itself seems better than the 1x90's, but the intake runners pull air from under the seat, above the rear tyre, so you're effectively kicking up your own dust to suck in if riding offroad. It seems like the main paper air filter element can get overwhelmed quite quickly, and then the suction/vaccuum from the motor finds any weak spot in the airbox to suck dirty air through.
The fact that pretty much all the cam problems are on the intake lobes makes me wonder if the cam problems, and dusted engine problem don't correlate somehow.

An entire industry has sprung up centered around air filters for KTM Adventure bikes

 

[Roadhawg011]

Can someone educate me on the difference between JASO MA and MA2 spec? Would the MA2 spec product have less zinc?

 

[ZeeOSix]

Can someone educate me on the difference between JASO MA and MA2 spec? Would the MA2 spec product have less zinc?

Click on the top link for JASO T903 spec doc on 4-stroke motorcycle oil - PDF download. The difference between MA1 and MA2 is the friction level of the oil. JASO "MA" encompasses the total friction range of MA1 and MA2. The JASO doc shows all the specs required to meet JASO specs.

JASO Engine Oil Standards Implementation Panel

There are lots of threads in this forum that dive into the JASO spec.

The only oil additive that has set limits in JASO is for phosphorus. All the others, including zinc, are just to report the level (no spec limits defined in JASO). If you can find a high zinc oil that meets JASO, the it meets JASO because of the other requirements.

​

 

[twX]

The fact that pretty much all the cam problems are on the intake lobes makes me wonder if the cam problems, and dusted engine problem don't correlate somehow.

The intake cams wouldn't be directly exposed to dust. The only way that dust is going to be getting to the cams is through the oiling system, so I doubt it's related.

Piston rings and bores are most susceptible to excessive wear from dust.

 

[BusyLittleShop]

Some 80s V-4 Hondas ate cams too (mostly surface material loss pitting), and it was a combo of bad cam material/hardening and insufficient oil supply.

Honda's ate cam but it wasn't bad cams nor oil...

The great camshaft crisis in 84 about off killed enthusiasm for the
V4... as you know every stop gap measure was tried in curing the
problem but the real culprit was Honda's short cut in machining steps
of the cam bearing blocks... they dropped the line bore step and
machined the cam bearing blocks separately... this resulted in mix
match of clearances... in short the cams flopped about... hard coat
damage soon followed... For a cure Honda... in 86... went back to the
more accurate and expensive method of line boring the cam bearing
blocks... You can note the external difference in the head design...
the 84's & 85's rubber valve cover gasket is flat... whereas the 86's
rubber valve cover gasket is half circled covering where it was line
bored...

Honda was typically silent for a long time and this led to all sorts of home
cures including better top oiling kits... shorten oil change intervals... larger
gapped valve clearances... installing new cam tensioners... auxiliary
cooling fans kits... etc etc etc... but none of these address the root cause...
Only after Honda took a lot of stick did they finally go back to the timely
process of line boring the cam bearing blocks on the head so the
tolerances complimented each other...

In the void of official guidance Mechanics went to great lengths to address
the symptom but failed to establish the root cause... the hard coat damage
was still miss matched cam bearing blocks... the evidence they needed to
look at carefully is the fact the edges of the cams fails first... their pet
theory of a lack of oil would make the center fail first...