Any wisdom on KTM 790/890 Cam wear problems?

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

Understanding Zinc...

Thanks to BITOG data I think we finding the single most common
misunderstanding about motor oil is that higher zinc levels provide
greater wear protection. fact is more zinc provides longer wear protection...
but thats a moot point given the short oil change intervals owners
favor...

Zinc is not even a lubricant until heat and load are applied. Zinc is
only used when there is actual metal to metal contact in the engine.
At that point zinc must react with the heat and load to create the
sacrificial film that allows it to protect flat-tappet camshafts and
other highly loaded engine parts.

Quote 540Rat

So, modern low zinc oils CAN BE USED SAFELY with flat tappet cam
setups, even in engines with radical cams and high spring pressures.
Simply choose from the higher ranked oils on the list at the end of
this write-up, and you’ll be good to go. I know people who’ve been
using modern low zinc oils in High Performance flat tappet set-ups for
a long time, and they’ve had no issue at all.

Zinc is used/sacrificed in very small quantities at time, so the total
amount present in your oil does not change how much wear protection
the oil provides, as long as you don’t run out of zinc. “Lab Testing”
and “Wear Testing” analysis proves/confirms that more zinc provides
LONGER wear protection, NOT MORE wear protection.

To make a informed decision like an expert you have to understand that
additives like Zinc and Phosphorous are used/sacrificed in very small
quantities over time, so the total amount present in your oil does not
change how much wear protection the oil provides, as long as you don’t
run out of additives “Lab Testing” and “Wear Testing” analysis
proves/confirms that more additives provides LONGER wear protection,
NOT MORE wear protection... just follow the oil change interval
tested and approved by Yamaha's engineers and your prized R1 should
meet and exceed your mileage expectations...

Zinc is used as an extreme pressure, anti-wear additive. But, zinc
“DOES NOT” build-up over time like some type of plating process. For
those who have actually taken an engine apart that has been running
high zinc oil, you know that you don’t find a build-up of zinc that
looks like some sort of coating or sludge build-up. Zinc does NOT work
that way. And zinc is not even a lubricant until heat and load are
applied. Zinc is only used when there is actual metal to metal contact
in the engine. At that point zinc must react with the heat and load to
create the sacrificial film that allows it to protect flat-tappet
camshafts and other highly loaded engine parts.

More from Flat Tappet know it alls...

1. Well known and respected Engineer and Tech Author David Vizard,
whose own test data, largely based on real world engine dyno testing,
has concluded that more zinc in motor oil can be damaging, more zinc
does NOT provide todays best wear protection, and that using zinc as
the primary anti-wear component, is outdated technology.

2. The GM Oil Report titled, Oil Myths from GM Techlink, concluded
that high levels of zinc are damaging and that more zinc does NOT
provide more wear protection.

3. A motor oil research article written by Ed Hackett titled, More
than you ever wanted to know about Motor Oil, concluded that more
zinc does NOT provide more wear protection, it only provides longer
wear protection.

4. This from the Brad Penn Oil Company: There is such a thing as too
much ZDDP. ZDDP is surface aggressive, and too much can be a
detriment. ZDDP fights for the surface, blocking other additive
performance. Acids generated due to excessive ZDDP contact will
tie-up detergents thus encouraging corrosive wear. ZDDP
effectiveness plateaus, more does NOT translate into more protection.
Only so much is utilized. We dont need to saturate our oil with ZDDP.
 
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.
Sounds like @High Performance Lubricants will have a market for No VII MA2 oils with extra trimer moly & hefty AW package in 10w50 and 10w60, eh?

Hang a real certification on it and make all the Austrians happy at $20/qt 😉
 
Understanding Zinc...

Thanks to BITOG data I think we finding the single most common
misunderstanding about motor oil is that higher zinc levels provide
greater wear protection. fact is more zinc provides longer wear protection...
but thats a moot point given the short oil change intervals owners
favor...

Zinc is not even a lubricant until heat and load are applied. Zinc is
only used when there is actual metal to metal contact in the engine.
At that point zinc must react with the heat and load to create the
sacrificial film that allows it to protect flat-tappet camshafts and
other highly loaded engine parts.

Quote 540Rat

So, modern low zinc oils CAN BE USED SAFELY with flat tappet cam
setups, even in engines with radical cams and high spring pressures.
Simply choose from the higher ranked oils on the list at the end of
this write-up, and you’ll be good to go. I know people who’ve been
using modern low zinc oils in High Performance flat tappet set-ups for
a long time, and they’ve had no issue at all.

Zinc is used/sacrificed in very small quantities at time, so the total
amount present in your oil does not change how much wear protection
the oil provides, as long as you don’t run out of zinc. “Lab Testing”
and “Wear Testing” analysis proves/confirms that more zinc provides
LONGER wear protection, NOT MORE wear protection.

To make a informed decision like an expert you have to understand that
additives like Zinc and Phosphorous are used/sacrificed in very small
quantities over time, so the total amount present in your oil does not
change how much wear protection the oil provides, as long as you don’t
run out of additives “Lab Testing” and “Wear Testing” analysis
proves/confirms that more additives provides LONGER wear protection,
NOT MORE wear protection... just follow the oil change interval
tested and approved by Yamaha's engineers and your prized R1 should
meet and exceed your mileage expectations...

Zinc is used as an extreme pressure, anti-wear additive. But, zinc
“DOES NOT” build-up over time like some type of plating process. For
those who have actually taken an engine apart that has been running
high zinc oil, you know that you don’t find a build-up of zinc that
looks like some sort of coating or sludge build-up. Zinc does NOT work
that way. And zinc is not even a lubricant until heat and load are
applied. Zinc is only used when there is actual metal to metal contact
in the engine. At that point zinc must react with the heat and load to
create the sacrificial film that allows it to protect flat-tappet
camshafts and other highly loaded engine parts.

More from Flat Tappet know it alls...

1. Well known and respected Engineer and Tech Author David Vizard,
whose own test data, largely based on real world engine dyno testing,
has concluded that more zinc in motor oil can be damaging, more zinc
does NOT provide todays best wear protection, and that using zinc as
the primary anti-wear component, is outdated technology.

2. The GM Oil Report titled, Oil Myths from GM Techlink, concluded
that high levels of zinc are damaging and that more zinc does NOT
provide more wear protection.

3. A motor oil research article written by Ed Hackett titled, More
than you ever wanted to know about Motor Oil, concluded that more
zinc does NOT provide more wear protection, it only provides longer
wear protection.

4. This from the Brad Penn Oil Company: There is such a thing as too
much ZDDP. ZDDP is surface aggressive, and too much can be a
detriment. ZDDP fights for the surface, blocking other additive
performance. Acids generated due to excessive ZDDP contact will
tie-up detergents thus encouraging corrosive wear. ZDDP
effectiveness plateaus, more does NOT translate into more protection.
Only so much is utilized. We dont need to saturate our oil with ZDDP.
Oh no… you quoted the Name that WILL NOT be spoken… the godfather of the one-armed bandit!! 😱
 
Honda's ate cam but it wasn't bad cams nor oil...
According to this article those were some of the factors involved.

https://www.math.uwaterloo.ca/~rblander/V4_cams.html

4. Soft cam lobe material.
Later replacement cams use different camshaft material and hardening procedure, so they should last longer than the original cams. As most of us are aware, Honda offered an extended warranty which essentially meant free cams and rockers whenever needed. This warranty was discontinued in 1989 or so, and it costs about $1000 or so for parts (camshafts and rockers).

6. Inadequate lubrication.
According to Honda Racing, all the previous items contribute to the problem, and if you adjust the valves properly with the special tool and have new cam chain tensioners and the harder cams, you may escape the problem. But one final factor remains: inadequate quantity and quality of oil to the top end. (Apparently, Honda has upgraded the oil supply lines to allow greater flow to the head, but this isn't enough. Refer to articles by Phil Rastocny ([email protected]) on do-it-yourself oil system modifications, including research of these oil supply line upgrades. Both Part One and Part Two are available on my web site.


And here is another perspective, that essentially says it all starts with crummy camshaft material and manufacturing, and the surface of the cams would start pitting, which then just started chewing up the follower, and then the cam lobe and follower just chewed themselves more as damage increased - a typical wear runaway situation in this case. My V4 Honda had this issue, and the cam lobes looked just like the ones in the photos in this link.

https://www.motorcycleproject.com/text/v4_cams_what.html
 
Last edited:
According to this article those were some of the factors involved.

You'll read plenty on the net but those articles do not address the root cause...

Honda's great cam shaft crisis was the result of a factory cost
cutting measure... they choose to mill the cam bearing blocks
separately... there was no matching of components... consequently the
cam bearing blocks were not line bored with the head... if the
tolerances happened to add up... the cam will flop about in the
head.. you'll notice the edge of the cams fail first... a sure sign
the cam shaft tilted and was allowed to strike the follower at an
angle... this also explains why some cams go 100K while other only
20K...

Honda spent a lot of money replacing hand cam shafts and matching cam
bearing blocks to erase the blemish on the V4 legacy..
 
I was wondering why the bigger 1190/1290 bikes never suffered this problem....It seems the 7/890 bikes have changed from a bucket/shim tappet to finger followers, which obviously take a bit more strain as well.


Thanks for the info guys. Much appreciated and I'll do some more reading.
 
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.
Wow...It's amazing these cams are so "fragile" in their pre-break-in form and that 20 mins at 2500rpm is the difference between failure and long happy life.
 
You'll read plenty on the net but those articles do not address the root cause...

Honda's great cam shaft crisis was the result of a factory cost
cutting measure... they choose to mill the cam bearing blocks
separately... there was no matching of components... consequently the
cam bearing blocks were not line bored with the head... if the
tolerances happened to add up... the cam will flop about in the
head.. you'll notice the edge of the cams fail first... a sure sign
the cam shaft tilted and was allowed to strike the follower at an
angle... this also explains why some cams go 100K while other only
20K...

Honda spent a lot of money replacing hand cam shafts and matching cam
bearing blocks to erase the blemish on the V4 legacy..
Where did this information come from? Got a link to the source?

As can be seen in some of the photos in the link I posted previously and again below, the cams can pit in the center with no signs of edge wear or damage, so I think it was more than just cam bore alignment going on. Mis-alignment of the cam bores could certainly add a factor to the failure that made cams with inferiour material/hardening go bad sooner than later.

https://www.motorcycleproject.com/text/v4_cams_what.html
 
Where did this information come from? Got a link to the source?

My friend Julian Ryder is the source... he wrote the book on Honda's V4... chapter 4 "the great camshaft crisis..."
Mr.RC45JulianRyder4.webp

Mr.RC45JulianRyder.webp

Mr.RC45JulianRyder1.webp

Mr.RC45JulianRyder2.webp
 
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 :ROFLMAO:
You can add the 690/701 to that list.
My new 701 sucked a lot of dust this weekend. I have the airbox off now trying to come up with a solution.
 
My friend Julian Ryder is the source... he wrote the book on Honda's V4... chapter 4 "the great camshaft crisis..."
View attachment 168476
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View attachment 168478
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Please explain how the line bore on a camshaft causes lobe wear. I can see how it could cause a cam to bind up or even break, but lobe wear??? If it made a camshaft not set parallel to the valves I could see it possibly? But 99% of flat cams I saw in my life of being a mechanic was crappy metal and/or crappy lubricant. It’s been probably 20 or so years ago that on Competition Cams website they posted if you didn’t use their engine oil supplement OR (this is going to ruffle some feathers) Shell Rotella, your warranty is void. I used a lot of their cams, and never had a issue.
 
Width of the lobe/follower contact patch. All the Pumpe Duese VW TDI's cams failed as well. Magic oil & be ****ed.
 
Hi Folks. Me again.

Just thought I'd share some info. I did oil analysis at the first (yearly) service on my 2023 Husqvarna 901 (Same motor as the 890). It came back with 6% fuel dilution(!) , but the tech at the dealer who drained the oil gave me the sample in a coke bottle. I thought maybe the guy cleaned the coke bottle with fuel before putting the oil sample in, but obviously wanted to check.

I did another ~2000km and took another sample, this time I was present and made sure it was all kosher.
Results below, not fuel dilution but still a bit low viscosity for a 10w60. (The manual for these bikes recommends 10W50, and the current viscosity would almost be right for a 10W50. The South African dealers tend to use 10W60 due to our higher average temps I believe)
Would this viscosity drop be due to shear? Is this acceptable?

Wear metals look to be decreasing. (Although the oil is half as used at the previous sample)

Screen Shot 2024-11-25 at 15.32.56.webp
 
Would this viscosity drop be due to shear? Is this acceptable?
All multi-viscosity oils are going to shear down in a bike with a shared sump due to the transmission gears. If the OM recommends 10W-50 and the 10W-60 stays in the 50 grade after shearing then I wouldn't worry about it.

Your Sample 1 UOA looks like the KV100 was 13.7 cSt, but that was probably mostly due to the fuel dilution on that sample. KV100 of 13.7 is a near the bottom of a 40 grade.
 
Looks good for the second sample at 2000km. Prorating the iron wear, it looks to be about the same as the first full OCI if extrapolated. Are there other UOA's to compare this engine to and see if that is par for the course with this engine?
 
KTM has walked back their block on warranty repairs for the L8C engine cam/rocker wear to some extent. They have a new program to reimburse owners who had to pay for repairs out of pocket. I've heard mixed results by people filing claims, though.

Regarding the cause, everything I've seen suggests low oil pressure is the primary reason. Apparently, the oil pressure to the cams is something like 1/2 that for an MT07 Yamaha.

Guys that flog their bikes, running high rpm, have less problems, because the oil pressure is higher at high rpm. Ride the bike easy, as many would do if riding off road, destroy the cams faster. And oddly, KTM added a filter in the oil galley feeding the head, which further reduces oil pressure by increasing restriction. Seems like a really bad situation. KTM is in serious financial trouble also. Personally, I'd love to buy a 790, but there is no way I'd do so now.
 
And oddly, KTM added a filter in the oil galley feeding the head, which further reduces oil pressure by increasing restriction. Seems like a really bad situation.
If the secondary filter is filtering oil that's already gone through the main oil filter, might be a good idea to remove it to get more oil to the head and valve train. That filter to the head probably isn't filtering anything out if it's already been caught in the main filter.
 
Good thought, Zee. Makes sense.

My Kawasaki ZRX1200 is notorious for low oil pressure at idle. Kawasaki recommends 10w40 in general however a good 20w50 has been easily proven (pressure readings with a remote tester) to provide more psi than 10w40 at that low rpm. Also, bumping the idle rpm a couple hundred doesn't hurt anything either.
 
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