400 SS valves in a 426


29 replies to this topic
  • PBDBLUE

Posted September 18, 2010 - 03:38 PM

#1

My buddy's WR426 has been a little hard to start lately so I checked the valves and the center intake is toast. All the others are good. I started looking into parts. One stock Ti intake is over $100. I noticed that Kibblewhite lists the same valve for 98 - 02 in stainless which got me thinking can you use the stock stainless valves for the 400 in a 426? The stock SS valve is only $15. If I replace all the valves, springs and seals with ss I'm only into it about $150 + getting the seats cut. He's a weekend play rider and is not hard on the bike so I'm thinking stainless might be the ticket. I'm going to tear the head down tomorrow and see what's up. Anybody try this before?

  • PBDBLUE

Posted September 18, 2010 - 05:06 PM

#2

Oops. Forgot to search over in the YZ forum. A ton of info there. Apparently it's no problem.

  • mweitz

Posted September 19, 2010 - 03:37 AM

#3

Interesting, can you post up when you are finished?

  • PBDBLUE

Posted September 19, 2010 - 05:46 AM

#4

Interesting, can you post up when you are finished?


No problem. I forgot that the 2000 YZ has basically the same head with stainless valves so you can just use parts for that year/model. Looks like the total cost for all new valves, springs, seals and head gasket will be under $200 with the good guy discount. Some guys recommended getting the 2000 YZ retainers and cotters as well but when I looked them up they have the same part number as the 01.

  • Birdy426

Posted September 20, 2010 - 05:00 AM

#5

I would replace the cotters anyway...they are cheap, and that way any wear in issues with the old cotters and the new valves are eliminated.

  • PBDBLUE

Posted September 20, 2010 - 05:47 AM

#6

I probably will. Actually the top end looks pretty good with the exception of the one intake valve. Ring end gaps are well within spec as well as the bore and piston. All the other valves and seats look fine. Still you can replace all the valves with stainless for not much more than one titanium. I know the history of this bike very well. I bought it new and later sold it to my buddy. I don't know how many miles are on it but I'm sure way less than 10,000 and probably closer to 5,000. It's plated and not his primary desert ride. I'm a little surprised the valve went away so early. My '03 had the same issue but it had a lot more miles on it.

  • mweitz

Posted September 20, 2010 - 05:57 AM

#7

What are the plus / minus of stainless valves over titanium?

5 to 10K miles is pretty good for not having done the valves isn't it? Do you think you will get the same out of stainless valves, or do you just plan on doing the job more frequently now?

  • PBDBLUE

Posted September 20, 2010 - 06:58 AM

#8

Pluses are cost and longevity. Minus is some small decrease in top end performance that the average trail rider won't even notice. As far as when to do it my experience with Yamaha 4xx's (and I've owned a bunch of them) is when you have to shim the same valve more than twice or it moves a lot (>.1mm) it's time. It seems the center intake is usually the first to go.

  • mweitz

Posted September 21, 2010 - 08:24 PM

#9

Interesting.

I was looking at valve prices today just for s*@#s and grins. Looks like Kibblewhites are like 25 each, other stainless are in the 18.00 range and you can find Yamaha Titanium valves in the 75 each range.

I found a full OEM kit for 420.00, which seemed to be a good price.

I just put a "new" engine in my bike (700 miles) so I have a ways to go, but wanted to figure out the best way to go when mine start to go. I figure if I start picking up pieces here and there by the time I need a valve job I'll have it all.

Thanks,

Mark

  • PBDBLUE

Posted September 22, 2010 - 08:23 AM

#10

I have oem Yamaha valves on order. They ended up being around $13 each for the intakes. Exhausts were a bit more. Still I'll have less than $200 in it including the head gasket. Piston and cylinder both measured well within spec so I'll just go with new rings.

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  • grayracer513

Posted September 22, 2010 - 10:24 AM

#11

Be absolutely certain to use the springs from a 2000 engine as well. Since the SS valves are nearly twice as heavy, they require heavier springs to control them.

  • PBDBLUE

Posted September 22, 2010 - 01:09 PM

#12

Be absolutely certain to use the springs from a 2000 engine as well. Since the SS valves are nearly twice as heavy, they require heavier springs to control them.


Already on order:thumbsup:

  • grayracer513

Posted September 22, 2010 - 01:28 PM

#13

Cool. I should point out that for anyone considering KW's on a WR or YZ450, you'll want to find an alternative to their spring set. There are no heavier springs available from Yamaha for the 450's, and KW's set runs over $200, mostly because they use titanium retainers. Technically, it's a good idea, but it won't help save money.

  • mweitz

Posted September 22, 2010 - 03:33 PM

#14

As a point of reference, you can order a Yamaha OEM titanium kit for about 420.00 without the gasket or shipping.

Retail for all the parts at CheapCylceParts.com is about 480.00.


I have oem Yamaha valves on order. They ended up being around $13 each for the intakes. Exhausts were a bit more. Still I'll have less than $200 in it including the head gasket. Piston and cylinder both measured well within spec so I'll just go with new rings.



  • PBDBLUE

Posted September 22, 2010 - 06:09 PM

#15

Does that include the guide seals as well? For the intended use I think stainless will give better service at a much lower cost.

  • mweitz

Posted September 22, 2010 - 06:16 PM

#16

Does that include the guide seals as well? For the intended use I think stainless will give better service at a much lower cost.


I'll have to find the link, but I'm pretty sure it included everything on the 426 Parts Fiche page for valves except shims.

I make no claims as to what is better. I have no idea which is better for which application, just posting the cost differential for those of you that do know so it is easier to make the comparison.

I only have 700 miles on my bike, so I'm a ways away from a valve job (hopefully) but I want to decide how I'm going to do it sooner rather than later, and then slowly start amassing the parts so I don't have to drop an 800.00 repair bill on my wife :ride:

  • PBDBLUE

Posted September 22, 2010 - 07:23 PM

#17

I'll have to find the link, but I'm pretty sure it included everything on the 426 Parts Fiche page for valves except shims.

I make no claims as to what is better. I have no idea which is better for which application, just posting the cost differential for those of you that do know so it is easier to make the comparison.

I only have 700 miles on my bike, so I'm a ways away from a valve job (hopefully) but I want to decide how I'm going to do it sooner rather than later, and then slowly start amassing the parts so I don't have to drop an 800.00 repair bill on my wife :ride:



Stainless is a very popular replacement option for the Honda's. Frankly I don't think the average weekend warrior could tell the difference but the stainless will outlive the Ti valves by a good margin.

  • mweitz

Posted September 22, 2010 - 07:52 PM

#18

Stainless is a very popular replacement option for the Honda's. Frankly I don't think the average weekend warrior could tell the difference but the stainless will outlive the Ti valves by a good margin.


Do Honda's come with titanium valves? Like the older 250X?

I guess I was under the impression they were stainless stock, and the Kibblewhite stainless was just a "better" stainless valve that people liked to use.

:banghead:

I do have an 04 250X that I work on that is going to need valves soon I bet, which is another reason I'm starting to pay attention to valve threads. I think for that one we will most likely go with the Kibblewhite.

Additional performance isn't necessary on our bikes, they are more bike than we need / can use anyway. The 250X rider is a lady with about a year of riding and I have about 1.5 years experience so the 426 is like a frigging race car to me :ride:

Thanks!

Mark

  • grayracer513

Posted September 23, 2010 - 08:03 AM

#19

I think stainless will give better service at a much lower cost.

It will certainly give at least equivalent service at a much lower cost.

Do Honda's come with titanium valves? Like the older 250X?

Some do, some don't. Honda's valve problems or lack of them are another whole issue, and not the subject of this forum. For specific Honda information, please visit the appropriate Honda forum.

  • mweitz

Posted September 23, 2010 - 08:12 AM

#20

It will certainly give at least equivalent service at a much lower cost.

Some do, some don't. Honda's valve problems or lack of them are another whole issue, and not the subject of this forum. For specific Honda information, please visit the appropriate Honda forum.


Sure it was relevant, based on post #17. That poster was showing that a lot of Honda owners use stainless replacements as well. If they are replacing stainless with stainless it doesn't mean much, if they are replacing titanium with stainless it shows something.

If you have an issue, start up there.

Mark




 
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