Yz 426 rebuild. What can you say about my valves?


8 replies to this topic
  • kubamtx

Posted June 19, 2012 - 12:32 PM

#1

Hi
Due to pistone seizure I'm rebuilding my 426 engine. Con rod and piston has been rebuild 3 years ago and now I'll do even more. So pistone, con rod, cranckshaft bearings, main bearing, all selas, new water pump new cam chain and few more things.
But I don't want to spend a lot of money on my cylinder head if it is in good condition. So I've took of the valves and took a lot of pictures. Please take a look and share with me your opinion. My feeling is that thay are in good condition but I want to be sure.

Thanks for any feadback.
links below
https://picasaweb.go...feat=directlink

https://picasaweb.go...feat=directlink

https://picasaweb.go...feat=directlink

https://picasaweb.go...feat=directlink

https://picasaweb.go...feat=directlink

https://picasaweb.go...feat=directlink

https://picasaweb.go...feat=directlink

https://picasaweb.go...feat=directlink

Edited by kubamtx, June 22, 2012 - 10:24 AM.


  • marv02

Posted June 19, 2012 - 04:07 PM

#2

Hi
Due to pistone seizure I'm rebuilding my 426 engine. Con rod and piston has been rebuild 3 years ago and now I'll do even more. So pistone, con rod, cranckshaft bearings, main bearing, all selas, new water pump new cam chain and few more things.
But I don't want to spend a lot of money on my cylinder head if it is in good condition. So I've took of the valves and took a lot of pictures. Please take a look and share with me your opinion. My feeling is that thay are in good condition but I want to be sure.

Thanks for any feadback.
Below please find link to my picasaweb album.

https://picasaweb.go.../kubamtx/Yzf426


Link would not open for me.

  • kubamtx

Posted June 21, 2012 - 06:38 AM

#3

Hi
Now it should work.

  • sid_125_04

Posted June 22, 2012 - 01:41 AM

#4

nop now working for me

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • kubamtx

Posted June 22, 2012 - 10:25 AM

#5

I don't know this link is not working properly. Now I've added directlinks so it should work perfect.

  • SWIGIN

Posted June 22, 2012 - 12:52 PM

#6

I Don't know what I'm seeing in this picture but the face looks to be pitting. From your pictures this is the only valve that looks in bad shape as long as the stems are in spec.

Posted Image

Edited by SWIGIN, June 22, 2012 - 12:55 PM.


  • kubamtx

Posted June 23, 2012 - 01:05 PM

#7

Hi
Steams are in specs.
The valves withi shining silver ring this are intake valves and both exhoust valves after celaning are looking like that:
https://picasaweb.go...feat=directlink

As far as I remember they're looking exaclty the same as 70h ago.
I have this bike since 6 years. The head has been rebuild just before I bought it and I've re-shimmed just few hours after purchase and till now it's still on the same shimms. And the head is over 400h after rebuild.

  • boricua1

Posted June 26, 2012 - 08:57 AM

#8

Like this other guy said the only thing I see is the pitting. And the other way you can check to see if they are seated correctly is by putting them back into the head and spray some carb cleaner into the intake and exhaust ports of the head and look at the bottom of the valves for any leakage.

  • kubamtx

Posted June 26, 2012 - 11:28 AM

#9

HI
Thanks for feedback.
I've done the leak test like it is in the owners manual. So I've pured some cleaning solvent into the intake and after this into the exhoust ducts and checked for leaks- result- no leaks.





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