TOPIC:

Would anyone consider reusing an o-ring or gasket in a top-end build, especially an 11009-1208?  
See ebay item 203882422182






 

That o ring is often reused as its the head gasket that does the real work. 
Other gaskets use new wherever possible. 

I'd replace it.  Not worth the risk.

me 2

I've re-used the o ring when it's in good condition.  I don't re-use head gaskets but for some strange reason I hang onto them if they come off the head in good condition.  It's kind of like keeping that worst pair of underwear because....well you never know when you might need them in an emergency.

Exactly! I still have this Triumph triple head gasket hanging in my shed for what reason I’ll never know. I should throw it out.
But I may need it someday.

The only gasket I have ever reused is the  Z1, Kz900, and early model Kz1000 valve cover gasket. Of all the Kz900's/Kz1000's that came down with a head gasket leak I have looked at it always seem to be the that center O-ring that started leaking. I never reused one on any of my builds.
I also smear some Three Bond TB-1211 on the center o-ring just to give it some extra sealing ability.  Yea I know the factory manual doesn't tell you to do that, but I do!!!
None of my KZ motors ever had a head gasket leak over the years...........

 

I do not reuse orings my moto if you cannot afford to do it right you damn sure cannot afford to do it wrong.