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HELP!- Valve Seal replacement...

Started by europe50, April 16, 2010, 01:02:45 PM

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europe50

Hello,
  When I first got my bike (3 years ago) my bike smoked only at start-up kind of bad, so I replaced my valve seals with new ones ("EOK" valve seals) and they looked identical to the originals and were a little tighter around the valve (In a good way). But after I was done it still smoked badly even after a few rides. I think it smoked even worse when I was done, so I rechecked the valve seals and they were down all the way and no damage that I could see.
  Compression is great and consistent and it does not burn oil once warm unless it sits for a while and cools down. I even took the exhaust off and started it to see if maybe only one cylinder was smoking worse than others because of a bad seal, but all four were pretty even in smoking at start-up.
  If I look in the cylinder, there is a little oil on the top of the piston, but I don't know what else to look for considering the bike runs awesome and I really don't want to take that bike apart again without a good idea of what else could be wrong.

Any ideas?
Here are the "EOK valve seals" on ebay: http://cgi.ebay.com/ebaymotors/YAMAHA-FJ1100-FJ1200-FJ-1100-1200-VALVE-SEALS-VITON_W0QQcmdZViewItemQQhashZitem35a797917dQQitemZ230444994941QQptZMotorcyclesQ5fPartsQ5fAccessories

I am very mechanically inclined and worked as a mechanic and owned a mechanic shop for years.

SlowOldGuy

Not sure what to tell you.  My "smoke on startup" problem was cured by new valve seals (stock).

DavidR.

pdxfj

I just put a set of the seals you linked to in the '86 I have.  Cured the smoking problem.  Thankfully the '86 is going to a new owner soon.  Yay.. more space in my garage.  :)

If I were going to do the valve seals on my '87 I would buy them from Randy.  The ones he carries are far superior to OEM or any other aftermarket.  Although you do pay a price for them.



Perhaps do a leak down test??  Did you replace the dowel gaskets when you pulled the head?

SkyFive

I just replaced my valve stem seals, last week, with EOK Viton seals. One of the new seals split around the top as I was pushing it on (I think). I took the split seal off and I could not tell it was split unless I pinched it, otherwise it looked fine. It made me wonder if it was split before I installed it or if it split while installing it. Anyhow, the split was apparent when it was installed.

Damaged


Undamaged

europe50

Quote from: pdxfj on April 16, 2010, 04:49:08 PM

Did you replace the dowel gaskets when you pulled the head?
Where and/or what are the dowel gaskets?

europe50

Quote from: SkyFive on April 17, 2010, 04:25:49 AM
I just replaced my valve stem seals, last week, with EOK Viton seals. One of the new seals split around the top as I was pushing it on (I think). I took the split seal off and I could not tell it was split unless I pinched it, otherwise it looked fine. It made me wonder if it was split before I installed it or if it split while installing it. Anyhow, the split was apparent when it was installed.

Damaged


Maybe I damaged them, I will have to check again. I never do a job twice, I can't believe that I took this apart two times already.

pdxfj

The dowel gaskets go into the jugs around the #4 outer stud holes.  They are for sealing up the oil galleys for the head.  Then the copper washes on the cylinder head are what seal the galleys at the top.

If you go to the Yamaha parts site and go to Cylinder and look at parts 3 & 4 you'll see what I am talking about.

I'd go nuts if I had to take it apart more than once.  Get in touch with Randy and he will put together a kit of everything you need to do the job.  Might want to consider a new cam chain tensioner if you haven't already.

Sorry if this is written a bit funky.. Coffee hasn't kicked in yet..

Quote from: europe50 on April 17, 2010, 06:55:11 AM
Where and/or what are the dowel gaskets?