What I found......Nuthin'!

4 replies to this topic
  • BrandonW

Posted July 30, 2002 - 04:52 AM


I pulled my engine apart last night, and right now I am thinking that it was all for naught.

The valves were a little tight, but nothing that is going to cause damamge. Intake were the tightest, but I could still slide a .125 mm feeler guage, and the manual says .15-25 mm, so that is not terrible. Exhaust were about where they should have been. Seeing nothing there, I went deeper.....

Pulled the head off, and there has been no contact with valves to piston head. No strike marks at all. In fact, the way that the sparkplug electrode is recessed into the head, there is NO WAY that the piston could hit that thing. I now have no idea how my original plug got struck.

Checked the sides of the piston and the rings for signs of metal transfer. Nothing. The cylinder walls were in great shape, and you could still see the swirl marks from a hone.

So, now I have an engine apart, and have no clue as to why it died.

Can I reuse my gaskets if I give them a shot of the KW CopperCoat stuff? Ordering those will probably take a week or so. I am planning on adjusting my intake valves, doing the YZ timing, and putting the thing back together. What else can I do?

I should be happy to not find catastrophic damage in there, but now I have no clue.


  • lewichris

Posted July 30, 2002 - 05:48 AM


wow you are a brave soul talking your engine down like that. I dont have balls even close to that big to try that stuff. Good luck and make sure you have a CR8E plug to put back in to it.


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  • Rich_in_Orlando

Posted July 30, 2002 - 06:43 AM


Originally posted by BrandonW:
...Can I reuse my gaskets if I give them a shot of the KW CopperCoat stuff...

I wouldn't do it. Not that I haven't considered it myself. But I wouldn't want to have to do the job twice all because of a bad gasket. I have reused head gaskets on other bikes, but they didn't have nearly as high a compression ratio and they were air cooled. Order youself some new gaskets so you have peace of mind.

[ July 30, 2002: Message edited by: Rich in Orlando ]

  • BrandonW

Posted July 30, 2002 - 07:59 AM


Just got back from the local Yamaha shop, and they have no idea as to what I might be chasing.

They did not have any gaskets in stock (no surprise there) so I had to order them. They are a minimum of a week out, so I guess that I have to sit on this and wait. The waiting is the hardest part.

Am thinking about taking the bike down to the Yamaha shop and have them put it back together.


  • John_Lorenz

Posted July 30, 2002 - 09:45 PM


In a bind as long as the copper gasket is a pure copper gasket

meaning no Asbestos of fiber lining, you should not see any whit fillament between the copper linings.

you can heat the gasket on you stove or bake it at 400 for about 30 minutes.

This expands the copper and makes it usable again.

Again you can do this in a pinch...

Allow the copper to cool naturally

Oh and use gloves :)

[ July 30, 2002: Message edited by: E.G.O.**** ]


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