01WR426 small end rod galling...

2 replies to this topic
  • SFO

Posted June 09, 2001 - 07:09 PM


WR/YZ 426F Weirdness...Help?
I just pulled my 01wr426 apart to send Eric Gore my cylinder for the O.S. bore connection.
Surprise, surprise when I got the head off.
The center intake valve has been clipping the edge of the piston cutout leaving a shiny rolled corner on the piston...
The small end of the rod is also starting to gall.
The piston pin is definetly toasted.

The book says .016-.039" freeplay at this junction.
This appears to be a misprint.
I would personally set it up at .0015-.002"...It is at .0015"...This is actual measured clearance, the manual is a bit ambiguous here. It doesn't call out how they are applying their dimensioning to reality.
I hate designers...Just give me a drawing I will make it.
Has anyone seen these symtoms/problems on a stock bike?
Any insight would be considered.

[This message has been edited by SFO (edited 06-10-2001).]

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  • Guest_Guest_*

Posted June 11, 2001 - 03:37 AM


What were the symptoms, sounds that made you liik into it?


  • SFO

Posted June 12, 2001 - 03:14 PM


It wasn't making any noises...
I disassembled it to get a Gore big bore.
Look at what I found.
Kinda hard to warranty something that I took apart.
Or that has no symptoms.
I am just seeing what I see.
I will certainly clay it upon reassembly.
The wrist pin also took the brunt of the galling.
I believe a new wrist pin and a light ball honing is going to straiten that out.
I was curious if there was a history of rod problems on this motor.

[This message has been edited by SFO (edited 06-13-2001).]


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