2000 426 Valve question


3 replies to this topic
  • STL450rider

Posted December 28, 2011 - 09:26 PM

#1

Ok heres the scoop: when i bought this bike, the guy told me it was a 2001, mentioned that it had titanium valves... I reshimmed the valves, wouldnt start, so i pulled the head to inspect. I did some reasearch on the VIN number on the frame and from my understanding its a 2000, not a 2001. All of the valves on the bike are original except for the middle intake valve, which looks to be titanium, and its much lighter than the rest. Could this be a problem? having one titanium valve and the rest stainless steel or w/e theyre made out of? Oh and by the way it turned out that 3 of the valves didnt have the keepers locked in place, i guess giving me innacurate readings? I hope this is comprehendable ha.

  • 2grimjim

Posted December 29, 2011 - 04:50 AM

#2

The '00 426's had steel valves from the factory and '01's had Ti valves. If you have one Ti valve, it's not original.

The Ti valves require a lighter spring and less seat pressure than the steel valves. This is usually a problem when owners of later bikes switch from Ti to steel valves because the springs for the Ti valves don't adequately control the heavier steel valves at high RPM. Using the spring for a steel valve with a Ti valve is not good either. The softer Ti valve can't handle the extra seat pressure and will quickly wear out the seat face.

You mentioned that you reshimed the valves. Did you recheck the clearances after reassembled the valvetrain? When you refer to the keepers not being locked in place, that leads me to believe that someone mixed up the keepers when they had the head apart. The keepers are different size for the intake and exhaust valves.

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  • STL450rider

Posted December 29, 2011 - 06:36 PM

#3

Took all of the valves out, they are all straight. The one intake port with the Ti vavle looked like it was leaking (carbon buildup), so i cleaned that up and I plan on buying a steel vavle to replace it. And yes I rechecked the clearances after i reassembled, and they were almost the same as before I reshimmed, which doesnt make any sense to me. The Keepers were all the way in place, but they didnt seem to fit on the ti valve like they should.

  • grayracer513

Posted December 29, 2011 - 07:56 PM

#4

The keepers are the same for the 2000 SS valves and for the '01-'02 Ti valves, but they may be worn.

The fit and position of the keepers also has nothing to do with valve clearance unless they cause the spring retainer to tilt at a significant angle. The shims sit on top of the valve stems, and the lifters on top of that. The vertical position of the spring retainer is not a factor.





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