hard to replace valves??


12 replies to this topic
  • ScramblerTom

Posted May 19, 2011 - 06:11 PM

#1

The intakes on my 05 400 exc are done. Do I just buy new ones and drop them in and I'm good to go?? I heard you are not supposed to lap a RFS valve. So can I do this myself or do I need to take the head and new valves to a shop?

the head looks great, no pitting or damage, just worn intakes.

  • caflashbob

Posted May 19, 2011 - 08:59 PM

#2

The intake seats need recutting normally.

Use Kibble white valves.

Replace any cupped adjusters or you cannot use a feeler gauge.

50,000,000 impacts wear the bottom of the adjuster foot.

Bob

  • ScramblerTom

Posted May 21, 2011 - 06:25 PM

#3

The intake seats need recutting normally.

Use Kibble white valves.

Replace any cupped adjusters or you cannot use a feeler gauge.

50,000,000 impacts wear the bottom of the adjuster foot.

Bob


If I use Stainless Steel valves I can lap them in - right? It is only the Titanium valves that have the hard coating, correct.

Anyone order direct from Del West? That's who makes Kibblewhites, or is that Black Diamond (or something like that).

  • caflashbob

Posted May 23, 2011 - 09:54 PM

#4

No lapping needed.

Just cut the seats

Kibble whites valves are called black diamonds.

Del wests are ti and need different springs to go with them.

$1572 from ktm.

Kibble whites are $35 each.

And work with the stock springs.

Who is doing this work?

  • ScramblerTom

Posted May 24, 2011 - 06:55 AM

#5

I was hoping I could do the job myself - hence hoping to lap them. I do not have the tool to cut the seats. I have read of people lapping Stainless Steel valves in RFS engines to fit them - is this not the case?

  • ScramblerTom

Posted May 24, 2011 - 07:17 AM

#6

just called the machine shop here in town $60 to cut in the two intake valves.

Does that sounds right?

I assume that the valves in there are Ti.

What is the reason for replacing the springs - the weight of the SS valves? if I go with new Ti valves do I have to replace the springs?

You hear about people replacing valves for under a hundred dollars - but this is going to be over $250 if I have to buy the $180 kibble white intake kit!

What about Pro X Steel valves? anyone use them?

  • ScramblerTom

Posted May 24, 2011 - 07:56 AM

#7

just spoke with Greg down at Orange Motosport and I am getting OEM steel valves. the head is in great shape with no damage and I can lap these in with the same hardware just new seals.

So for under $100 I get it done. :smirk:

  • AZRIDER44

Posted May 24, 2011 - 08:42 AM

#8

why do you need to cut the valve seats? is there a way to replace valves without cutting them? what is lapping them in mean? sorry about all the questions. thanks in advance

  • caflashbob

Posted May 24, 2011 - 06:09 PM

#9

just spoke with Greg down at Orange Motosport and I am getting OEM steel valves. the head is in great shape with no damage and I can lap these in with the same hardware just new seals.

So for under $100 I get it done. :smirk:


There is a large rounded area of the seat from the worn ktm valve.

No way I would duplicate the damage already done by grinding the worn and unworn surfaces together.

Kw's intakes are $35 each and last forever. Factories are soft.

Never mind

Doc bob

  • caflashbob

Posted May 25, 2011 - 05:53 PM

#10

I was hoping I could do the job myself - hence hoping to lap them. I do not have the tool to cut the seats. I have read of people lapping Stainless Steel valves in RFS engines to fit them - is this not the case?


I have a free fix. I have two lightly worn ktm intake valves that are starting to cup.

Will fit right on your partially rounded seats and give you a good valve seal and 100-200 hours more life.

Send me your shipping info.

If Canada you pay the extra to get these north of the border. Ok?

Doc bob

  • Kenzo

Posted May 26, 2011 - 06:06 AM

#11

just spoke with Greg down at Orange Motosport and I am getting OEM steel valves. the head is in great shape with no damage and I can lap these in with the same hardware just new seals.

So for under $100 I get it done. :prof:


i'm in the same boat as you...my 06 has 240 hours and the valves need replacing in the next 20-40 hours of use.

KTM intake valves are notorisly soft(RFS) hence the cupping and frequent valve adjustments every 20 hours. :lol:

ur cupped valves have worn/deformed the seats...putting in new stock valves will mean frequent valve adjustments, u'll be lucky to get 200 hours before they need replacement again since ur starting with worn seats and most likely u'll be slightly down on power due to the bad fit. :lol:

i'm going w/ Kibblewhite Black Diamond valves 1mm over on the intakes, have the seats cut, new stock springs and retainers(u loose a spring and it gets expensive :lol:). Probably replace the cam bearings while i'm at it. Not sure if i'll install them or have it done...also not sure if i'll upgrade the exhaust valves or not. :smirk:

With the upgraded valves frequent valve adjustments are a thing of the past and the valves will last a lifetime. :smirk::thumbsup:


:lol:

  • ScramblerTom

Posted May 30, 2011 - 02:54 AM

#12

So I thought I would be problem free by letting the pros do the work... I bought OEM valves and had the recommended shop cut them in. This is where all the valve jobs get done around here. Well with the bike all together it does not run - or rather it runs occasionally but with awful clacking. It also sound like it has little compression as the starter motor turns it over really really fast.

The clacking noise is certainly valve related - I have only let it run for about 10 seconds twice in case the piston was actually making contact with the valves.

I did not check to see if the valves sealed before I put the head on - I assumed that when they came back from the shop they were ready to go.

Any ideas what to check first? I will go and recheck the valve settings - I set them at TDC with the TDC finding bolt in place, so I can't be wrong, can I?? My timing was set with the TDC bolt in and the two dots on the cam Level with the head as per the manual so that's not it - besides when it is running besides the long noise the engine runs smooth (it is hard starting though)

another thing - when turns the engine with the starter as it does not start, I am not hearing the clacking - so maybe no piston contact??

Please help.

  • ScramblerTom

Posted May 30, 2011 - 09:56 AM

#13

I know I should get a leak-down tester (or rather make one) but for now I went out and did a simple compression test and it was 90. hhmmmm. so that is the reason for hard starting, I did check the exhaust valves and they were off, I had them about .01" too tight, meaning I had the tappet pushing the valves out too much. It did not run after I adjusted it but it couched and fired under the starter motor but not under its own power.

I am thinking two things:
1) I contacted the piston and bent the valves and now I can't get enough comp.
2) the old exhaust valves which I re-installed as they were in great shape are not sealing.
3) the new intakes which I had professionally cut in are not sealing.

Anything else I can check before pulling it all apart again?

I hate these KTMs with their endless cam chains - swedging that damn link was the hardest part of the rebuild and now it looks I have to go get a new one and do it all over again.





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