RFS valvetrain discussion (continued)

[Patman]

OK I've been having some off line discussion on this topic but am not inclined to re-open the old thread that seemed to go off into left field from what the original intent of the post was. We will not be bashing ANYBODY in this verion, instead we can try to logically discuss the topic and see what directions it might point us to.

Things I understand from the original post, bits of useful info I could pull from the entire thread and things I know from experience:

-Eric has seen a few instances of spring failure in the 400/520 RFS engine.

-I have first hand knowledge of a few instances of this happening as well, if any of these engines ended up Eric's shop I don't know.

-The springs used are the same as those found in the LC4 engine, this engine is generally a low rev XR/DRZ type of 4 stroke.

-I'll take an educated guess that the RFS cam is not the same as the LC4 cam. I'll also venture the RFS cams place a much higher load on the springs.

-I have seen numerous broken valve springs in american V8's that had stock springs and big cams.

-Nobody made much of the big YZF puking it's guts through the cases when it was new but now it's getting to be a more common problem.

-KTM used Husaberg to develop the RFS, both are great bikes but both are racing machines with higher maintenance needs.

Questions I ask: :think:

-If the original design was not flawed why is there a conical spring assy out now?

-This is still a somewhat new engine design, is it possible that perhaps as it ages we'll see more of these same types of failure?

-I seem to recall at one point KTM "officially" denounced the use of synthetics in the RFS yet they were using Shell synthetic and now use Motorex, why is this strange to me?

 

[KTM-Lew]

I think Eric came close to admitting he may have mislead us when he posted that he is now using an aftermarket spring that doesn't require modifying the spring seat area of the head. I am sure he meant to call attention to a possible problem.....maybe he could have done it with-out the flashing lights, bells & whistles. :uh:

I believe the basic design is fine. It IS a very high perf engine. Things break. Sure, I would like to see rocker-arms go away. But I don' t see anything to be concerned about for the "average" rider. Do I expect to ever have trouble with mine ? No! Spring breakage is usually caused by over-reving or floating the valves. The early versions that are now failing were for a lot of riders their first experience with a 4-stroke. Over-revving is very easy to do...coming into a turn hot and slaming it down a couple gears, commonly done on a 2-stroke, may be enough to cause damage.

IF you are the type of rider that must use every available RPM the engine can produce, you definitely need to keep an eye on the valve-train. I'm thinking a once a year tear-down and inspection for the hammer-head, rev it out types. Do I think the design is to blame? NO! Its the idiot turning the throttle!:laugh:

As to why the conical spring now? Progress? Product improvement? Need to wring every available bit of power out of a technically inferior head design, compared to the YZF? It should be noted that the new springs are only used on the SX version. The EXC/MXC is not typically going to be bumping the rev-limiter often. Guess maybe the desert racers could?

 

[Patman]

See everybody is focusing on what Eric may or may not have done with reguard to the REPLACEMENT pieces and is not seeing the original intent of what he was trying to convey.

KTM 400/520 Safety Notice: Valvetrain
KTM Safety Notice

The valve springs on these motorcycles are prone to cracking on the bottom coil, which can cause a catastrophic valve train failure, and in the most extreme circumstance, enabling the valves to contact the piston causing the engine to stop abruptly.

I suspected this was the case and now with this post and a few off line discussions I've had with people I'm pretty much convinced the problem he was tring to alert people to was totally blown over and something to poke holes in was the focus. Come on folks go read the original post in the thread in question, read it a few times and see if you can understand that we're not talking about conical springs, and retainers and SX vs. EXC/MXC but a fundimental issue with the as delivered springs in the 400/520 bikes which I believe until recently all used the same valve assembly?

Hey maybe I'm the one that's totally lost here, PLEASE show me were I'm not reading this correctly. Make me look like the fool here, it really shouldn't be that hard ;) This seems to be a pretty active topic still with all the views in a pretty short period of time so let's discuss it. How often do ya' get a chance to pound on TWO moderators at the same time :)

 

[KTM-Lew]

[
KTM 400/520 Safety Notice: Valvetrain
KTM Safety Notice

The valve springs on these motorcycles are prone to cracking on the bottom coil, which can cause a catastrophic valve train failure, and in the most extreme circumstance, enabling the valves to contact the piston causing the engine to stop abruptly.

1. OK. I want numbers. How many failures have their been? 5 0r 5000?

2. Has anyone else, besides the guy thats selling parts, seen a failure. Or multiple's?

3. What were the bikes used for? MX-Desert-Hare-Scrambles-Trail Riding?

4. Any evidence of overheating or over-revving?

5. Were the engines blown-up, definitely caused by dropped valves/broken springs? All of them?

6. Was this the first 4-stroke for this customer?

The main reason for the post was to strongly suggest replacing the stock springs on ALL 400&520's with the 03 conical or another aftermarket part. If you did not do this you were taking you life in your hands? :moon: :laugh:
That's what I got out of reading the original post. Does anyone else see it different?

Broken valve springs are part of making power out of a 4-stroke. RPM's are a valve-trains enemy! :aj: :flame: :)

 

[marcusgunby]

KTM lew you need to see eric was trying to warn users that the engine could stop abruptly-if his post means one person takes notice and checks, its worth it.

 

[Thump]

KTM Lew... who are you asking these questions to? Do you want someone to spoon feed you the answers? Christ man, investigate for yourself.

Some of you are taking shots at Eric for posting his professional opinion based on what he has seen and repaired, both the wear and new parts issue. I am going out on a limb here but I'd be willing to bet that he has seen enough internal components of KTM motors to know what he is talking about.

He gave you guys a heads up... Not a press release or a safety recall.... Just a heads up about what he has seen.

Your pride in your orange engineering has resulted in shots being taken at Eric's knowledge and integrity and that is truly a shame. After reading this why would anyone ant to come on here and post a problem that they had with a KTM...

 

[truespode]

I had a 2001 YZ250F and read that the crank was prone to going on it. I never had a problem with it. However, during maintenance checks I would double check things just a little extra to make sure things were good to go.

That notice of a possible issue made me pay more attention.

I now have a 2003 CR450F and there have been talk that the '02 and now some talk that the '03 valves go pretty quickly. Nobody I know with either have had any issues. However, I am taking notice a little more when I check my valve clearances.

If I had a KTM 400/520, I would be paying more attention to my valve springs as a result of Eric's post.

That is what I got from Eric's post... double check and look out for an issue that has been noticed by others.

Ivan

 

[Patman]

Lew let's consider that Eric get's sent engines or parts of engines not whole bikes. Also realize that it's not really his issue how the bike is used nor the level of skill the rider has. His job is to repair and modify based upon what the customer tells him. That being said the few instances I am aware of were on a B HS rider 2001 400 EXC, a 520SX (not sure of the year) that was Vet ridden mostly on MX tracks and some trails and another one I saw in pieces but am not certian of displacement nor use. Does this constitute an epidemic? No, I don't think so. A recall? Not really, but maybe some consideration given to inspecting these pieces every 50 hours or so might be a reasonable idea reguardless of use. I really can't say because I don't feel qualified to say but I do respect the opinion of people that do have the skills and experience to make the call. I think reguardless of if the information was brought up by Eric Gorr, Mitch Payton, or even a local KTM shop it is something that should be noted and then each owner decides on their own how they will deal with the problem. If it doesn't bother them then they can ride forever or until they get thrown over the bars and never see the valve train, it's not really my issue. If the situation were on MY plate I would do much the same thing as Ivan, just be a little more aware of the issue and maybe pop the pieces out for a visual inspection and even send it out if I wasn't comfortable diagnosing it myself. So I guess you could say yes I did see it differently than what you did.

 

[dstktmusa]

Originally posted by Patman
-If the original design was not flawed why is there a conical spring assy out now?-

I have to question this line of thinking. Just because a manufacturer changes the design of an item, does it mean that the original design was flawed?? KTM still uses the 2 spring set up in the EXC/MXC engine. Can they not make a good thing better?? Higher performance?? There was nothing wrong with the twin shocks on my grandpap's

I have done as much research as a guy can do on this subject. Out of the 1000's of people that read the board and own KTM RFS', I have only heard of ONE person that has seen a valve spring failure on a RFS and this person IMO did not give enough information.

yes, he did state it as a "safety notice" <--- IMO reads VERY SERIOUS

 

[Thump]

Originally posted by dstktmusa
I have done as much research as a guy can do on this subject. Out of the 1000's of people that read the board and own KTM RFS', I have only heard of ONE person that has seen a valve spring failure on a RFS and this person IMO did not give enough information.

yes, he did state it as a "safety notice" <--- IMO reads VERY SERIOUS

Well guess what? That one person has rebuilt more engines than all of the rest of us combine.

Just as Ivan stated above, when I heard prolems about the CRF Valves although I have never seen any but I am a bit more observant when checking valve clearances.

The other heads up in Eric's post was that if you order part number 594.36.028.044 to replace your old ones in your 400/520 you are SOL cause it does not fit and will need to either get aftermarket or have your head looked at.... :laugh:

 

[dstktmusa]

Originally posted by Thump
Well guess what? That one person has rebuilt more engines than all of the rest of us combine.
The other heads up in Eric's post was that if you order part number 594.36.028.044 to replace your old ones in your 400/520 you are SOL cause it does not fit and will need to either get aftermarket or have your head looked at.... :laugh:

That part number IS NOT GOING TO FIT the 400/520 as it ONLY fits the 450/525SX models that have the correct cylinder head on them. He/you/we need to check the applications before he/you/we order the parts.

You know nothing of my engine building background so to state that he has seen/rebuilt or been inside of more motors than all of us combined is just an assumption. Experience means nothing to me..............as i have been riding motorcycles for over 16 years yet there are racers that have raced 5-6 years that are much better riders than me.

 

[MrLuckey]

Back to the original thread:

Eric states "Recently I ordered the new parts for a customer whose engine I am repairing. The new spring part number is 594.36.028.044 and it is relatively inexpensive. The problem is it doesn’t fit the new cylinder heads that KTM is shipping to customers ."

So do those springs fit original factory heads? It sounds like "it doesn’t fit the new cylinder heads that KTM is shipping to customers."

How exactly would one inspect springs and determine if they need to be replaced?

If I de-facto replace my springs with the new design will the new springs fit in my factory head?

I for one DO want to be spoon fed if that's what we are calling it.- I believe if you took a poll you would find that is one of the HUGE assets of DRN is finding a wealth of information instead of spending years finding things out the hard way? No? I've seen hundreds of posts where people were spoon fed answers on nearly every subject and were mighty pleased to have the information. I thought that was one of the major selling points of DRN.

 

[Patman]

Originally posted by dstktmusa
I have to question this line of thinking. Just because a manufacturer changes the design of an item, does it mean that the original design was flawed?? KTM still uses the 2 spring set up in the EXC/MXC engine. Can they not make a good thing better??

Flawed is a general term. Maybe the flaw was that it was too heavy, not strong enough, the wrong color,.... If this isn't the case then why EXACTLY was the different spring assy created? You can't see it easily so it's not like a new fender, frame color or graphics. If it is better then why not apply it across the board? This is a very large topic with plenty of room for discussion and just because I state my opinion does not mean it's right or wrong, maybe I just need to be edu-ma-kated with factual information. I guess a good place to start is how many springs have been sold for the 2000-2002 RFS bikes? Does somebody have information from dealers reguarding why these pieces were sold? Also it seems you missed the statement I made so ya' might re-check and you'll see that there is more than "one" instance of this occurance and they were not all seen at Eric's shop. I've held a fractured spring in my palm from a bike I was considering for purchase. Is this as wide spread as the triple clamps issue? No. Is it as big as the cam bearing or pump seal problem? I don't think so, at least yet. Is it something to close you eyes, stick your fingers in your ears and run around yelling "La-la-la-la" over? I guess it depends on which side of the reapir bill your on. Cripes if somebody is not concerned about it then by all means don't sweat over it. If people do want to know then let's talk about it. Trying to continually shut the topic down by driecting the conversation into a direction of attacksand because I said so ideals makes ME more suspicious. The entire synthetic oil / clutch discussion comes to mind right away as one that had very similar tacts in it. In the end I believe the clutch was "modified" on later releases so that the issue was resolved. The cam bearing issue is now "improved" as well as the pump seal issue. The triple clamps are now "modified" so they don't crack. Why is it not possible that the springs are in need of "improvement" or "modification" or whatever term gets applied because they might just have a chance of failing? Heck as I've tried to point out maybe it's not a wide spread issue because there was a bad batch of springs, or out of tolorance machine or assembly work.

Now I'd REALLY like to keep this discussion open and on the topic of discussing the failure issue and how/why/what could possibly be causing these incidents that are currently known about.

 

[Strick]

I agree with dskmtusa's logic, and with TTRguy's. Desert races are a sea of orange and blue, and an occassional CR500 or KX500 thrown in here and there. I ride with over a dozen ktm RFS riders on a regular basis. The experience level ranges from Novice to high level experts, I have never heard of ONE valve spring failure. I have of one valve/head issue on a bike that probably had 3000 miles on it, 2 dozen races, and NEVER once did the owner adjust the valves. I will aslo admit total ignorance to the issues involved with the springs. Eric is a master technician IMO. When it comes to motorcycle engines, it is beyond difficult disagreeing with any comment Eric has on an engine.

I feel it is important for all of us RFS owners to be aware of the potential issue at hand. Anyone else who does not own an RFS, I would think, should care less about KTM valve springs.

I regress: I just spent 4 days with LOTS of DRN members who are all wonderful people. Many asked me why I only post on the Reno Ride topics. The answer lies in this thread. If you folks who were here in Reno last week look closely at the responses and who they are posted by will understand.

 

[Patman]

TTRGuy I agree it would be nice if spoon feeding was possible on this topic but the one problem that now exists is that instead of discussing the base issue several self proclaimed "experts" have chosen to weigh in with speculation AND as an added bonus pushed the one person with both the technical expertise and first hand knowledge of the situation out. Like I've stated here, I've held one in my palm and seen a couple bikes that experienced failure. Since I do not proclaim to be an expert in this field I can only pose questions and speak from the experiences I've had that relate to the causes of spring failure.

Perhaps some background information on those that claim to be in the know on this is in order? Eric's credentials are available for everyone to see that are not familiar with them. TTRGuy, Thump, Ivan and myself have all made it known we're no experts. So?.......

 

[Strick]

Pat - there is NO issue with synthetic oil. Me and ALL of my RFS riding buddies use Mobil 1 15W-50, which I learned about on DRN, BTW, Not one clutch failure. I have over 3500 miles on my RFS now and all is well.

 

[MrLuckey]

I agree Patman - I have no doubt that there have been spring failures and would like to install newer better ones if that is the correct thing to do. My problem is that the discussion has been about so many things that have either been counter-productive or about other things that I am now confused as to which heads, which springs and what modifications are necessary to get the best parts installed correctly. I guess when it comes time to check valve adjustment I could always order both spring sets from KTM along with an aftermarket set (from who knows where) and then see for myself if any or all fit correctly.

 

[jns]

Just what exactly is the difference in the SX that it requires a different type of valve spring?Does the cam have a different lift imposed on the valve that the EXC dual spring type would fail under.Sounds like,as a local dealer suggested,that the valves may be too tight on these bikes that are failing.Maybe that was KTM's fix for the EXC failures when they issued a valve clearance change so the valve spring wouldn't overcompress.I just got a used 01 400EXC and had the updated cam bearings and autodecompressor bolt installed by a dealer and confirmed they adjusted the valves per the updated specs.I tried to get the "updated water pump seal" but the dealer said the part #s are all the same since the 2000 models.

 

[bclapham]

Originally posted by TTRGuy
I for one DO want to be spoon fed if that's what we are calling it.

The problem i saw with the last thread was that if you want to be spoon fed, then you shouldnt bite the hand that is feeding you.

note added in proof. This comment was not directed personally to TTR, but rather the posters that were questioning Erics integrity.

 

[Thump]

Originally posted by dstktmusa
That part number IS NOT GOING TO FIT the 400/520 as it ONLY fits the 450/525SX models that have the correct cylinder head on them. He/you/we need to check the applications before he/you/we order the parts.

So that this does not turn into a "mods/admins are just sticking up for one of their own" I will stay out of this.

I will add this one last tid-bit before I go. I have spent the morning on the phone with Mike at CycleZone KTM and Eric Gorr trying to sot this out... And I don't even own a KTM. I only researched 01/02 400/520's and 03 450/525's

The part number for the 01/02 400 and 520 is 590.36.28.144
The part number for the 03 450 and 525 is 594.36.028.044

So Eric ordered the wrong part right? Wrong. The new part supercedes the old... Meaning you can not buy the old part anymore. If you order the 01/02 part number (590.36.28.144) from KTM you will get the new conical design (594.36.028.044) that does not fit properly. Eric told me that on the phone and I called H&H KTM and they confirmed it. The problem is simple, if you replace your springs with KTM's new ones they will not fit because the recess in the 01/02 head is 2mm too small and it will not seat properly.

Eric says that the old ones are prone to cracking and I have no reason not to believe him. If I owned an 01/02 I replace mine with the ones from Kibblewhite because they are high quality and they fit properly.


I hope that this clears up any confusion as to what the problem is.

 

[MrLuckey]

Ok so the deal is
1. The old style springs are prone to cracking (maybe moreso if not adjusted properly)

2. You can't get the old style springs from KTM.

3. The new conical ones don't fit the 02 and before heads properly.

Man KTM sure screwed that one up!

I'll order some Kibblewhites, replace when I do my first valve adjustment check and sleep better. Thanks :thumb:

Now can you get me a sammy and something to drink while you're up David? :laugh:

 

[Patman]

Leave it to a freakin' Honda rider to take the orange bull by the horns :thumb:

So now it seems we have some VERY interesting new information to discuss.

 

[Thump]

Originally posted by TTRGuy
Ok so the deal is
1. The old style springs are prone to cracking (maybe moreso if not adjusted properly)

Correct, according to Eric... I trust the guy.

Originally posted by TTRGuy
2. You can't get the old style springs from KTM.

If you order the old part number you will get the new one, so yes, you are correct.

Originally posted by TTRGuy
3. The new conical ones don't fit the 02 and before heads properly.

Exactly

Originally posted by TTRGuy
Man KTM sure screwed that one up!

Yup

Originally posted by TTRGuy
I'll order some Kibblewhites, replace when I do my first valve adjustment check and sleep better. Thanks :thumb:

Good choice

Originally posted by TTRGuy
Now can you get me a sammy and something to drink while you're up David? :laugh:

Go sit out side in your undies and wait for me to get there. :laugh:

 

[dstktmusa]

Originally posted by Thump



So Eric ordered the wrong part right? Wrong. The new part supercedes the old... Meaning you can not buy the old part anymore. If you order the 01/02 part number (590.36.28.144) from KTM you will get the new conical design (594.36.028.044) that does not fit properly. Eric told me that on the phone and I called H&H KTM and they confirmed it. The problem is simple, if you replace your springs with KTM's new ones they will not fit because the recess in the 01/02 head is 2mm too small and it will not seat properly.
I hope that this clears up any confusion as to what the problem is.

This information is only part correct. The old part number 590.36.028.144 DOES supercede however; it supercede's to 590.36.028.244 which is the 2003 450/525EXC/MXC 2 spring design. Have Mike 2x check this as this is the information I was given over the phone with KTM customer relations this morning.

 

[BCR-Bob]

I've followed this discussion from the start and have read every reply and argument given. I indeed appreciate EG for the heads up on the spring failures. Myself and others simply asked if he had any info regarding years and VINs of the bikes that he had seen the problem with. I didn't expect him to do any in dept research being that I'm sure he's very busy.
In the original thread EG made a statement about people not doing proper maintenance and the results he has seen due to this. By reading his post am I to believe that the spring failures he saw were in some way related to lack of proper maintenance in his opinion?
Many people (myself included) have made statements about their lack of problems with the RFS. In all honesty I'm sure that there are many bikes (RFSs) out there that have given their owners nothing but grief. It's just the nature of the game. I've known XR owners that had lots of problems with their particular bike and we all know how bullet proof those bikes are by reputation.
The issue with the conical spings and different heads has been explained in detail by dstktmusa and seems pretty straight forward to me. EXC/MXCs have different heads and springs than the SXs. Don't mix and match them and you will have no problems. This goes for 2003s only.
As I stated in the original thread, I had repeated sring failures on a LC4 with both factory and aftermarket springs. I also said that the engine had an aftermarket cam in it. I accepted the problems as one of the things that you have to deal with when you modify an engine. The RFSs that he saw I would assume were not altered from stock so if there is a problem with the springs then I just wanted a little more info on the bikes he was dealing with.
I think the problem that people had with the original thread was the urgency of the original statement and then the failure to acknowledge any questions. Calling people who question you "dumbasses" probably didn't help either.