Cam Seal Leaking... still

jetmechmarty

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I posted this on Rhy's thread back in October. I'm still suffering the same leak. The leak is on the rotating shaft as opposed to the outer perimeter. I believe the seals are marked ARS. When I pulled the cover, the spring was where it was supposed to be. I have 6.85 mm clearance to the bearing. The cover & seal goes in 6.0 mm. The lip on the camshaft is beyond the seal. I must be doing something wrong, but I'm clueless as to what it is. I probably sourced the seals from Revival Parts group (MikesXS). Anybody?
 
Yamaha originally used a 5mm thick seal here for the 1st couple years of production. Then they changed that to a 6mm thick seal. They have now gone back to selling the 5mm thick seal. MikesXS was selling a 7mm thick triple lip seal. They claimed it was better what with the extra lips, but being thicker, those extra lips may not make it onto the cam so are no help.
 
I was often replacing the seals with the original 7mm triple lip ones until reading the posts here about the 5mm seals. Now I use the 5mm seals and they are a lot less expensive than the oem seals from the local bearing and seal supply store. I give the cam a light clean with scotchbrite and ensure the seal is flush with the housing. I replaced every seal while I had the engine apart and now the head gasket leaks. 🤔
 
I have also heard that of different thickness on seals

I have also heard from excavators

MikesXS was selling a 7mm thick triple lip seal. They claimed it was better what with the extra lips, but being thicker, those extra lips may not make it onto the cam so are no help.

It is not always as with shaving the more edges the better
What can happen if you have Double lipped seals .. is that the first one closest to the oil. Is performing keeping Oil inside.
The second lip then runs dry ( More or less ) on the axle for a while ... and wears out ..And then when first lip wears out the second one has already been gone a long time
And leaking
So Stock is the way to go if you ask me right dimensions right quality tested at the factory.
Care at the installation it can happen at times that the lip gets a cut or scratch sometimes. Extra care and of course lubrication grease
I have even used a Grinding stone in a drill to round off an entrance edge on one of the left side seals cant remember which one.
The first attempt cut the seal.

It was a fine evening ,.and a Youngster having enjoyed a couple of drinks passing by saw me standing on the knees and he believed I was drilling right into the engine block .. having lost it.
 
Partzilla shows them in stock. I just ordered four. I just won't wash the bike until I get them.
I had forgotten about Partzilla 3rd party shipping. The sent a UPS tracking number. So, the post office will deliver in 3 days or four weeks.
 

As it turns out, each and every seal I’ve installed was OEM. I lubed the lip with petrolatum before installation. This is seal number three. I’m not convinced that it’s fixed.
image.jpg

This is maddening.
 
Is the seal pressed in as far as it can go It looks as if the seal lip is close to the edge. on the cam
Perhaps place a socket over it there and press a little it moves rather freely ( or some light hammer blows )
Is the flat gasket on the backside " Stock " thin enough and applied on a clean surface.

Are the special washers there under the 3 Phillips screws ?
 
Is the seal pressed in as far as it can go It looks as if the seal lip is close to the edge. on the cam
Perhaps place a socket over it there and press a little it moves rather freely ( or some light hammer blows )
Is the flat gasket on the backside " Stock " thin enough and applied on a clean surface.

Are the special washers there under the 3 Phillips screws ?
I see the washers in there.
 
light clean with scotchbrite
Doing that was my breakthrough with camshaft seals. Keeping that from leaking by preparing things, positioning the seals, has been covered well in here over the years. XSJohn suggested replacing the spring on the seal with a larger spring from a larger scrapped seal. I tried that once, don't really remember what the result was. But just scotchbriting the shaft works for me
 
Feel like bein' a test pilot Marty? I bought these awhile back when RobinC was having problems with his cam seals. Never got around to trying 'em and seeing how well they'd do.
The inner lip is 1mm smaller dia. than the originals 25mm.
I'll install and test these on my big bore engine eventually... but that's prolly a year or so away.

$3.50 per seal from Oringsandmore.


1653145506913.png
 
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Yes, buffing a shaft clean and shiny with a Scotch-Brite pad before new seal installation is an old mechanic's trick and often helps. Besides removing corrosion it will smooth out minor imperfections, giving the new seal a fresh surface to work upon. And even though the seal lip is just rubber, over time it can start to wear a minor groove in the shaft where it makes contact. The Scotch-Brite pad will smooth this out as well. The end of the camshaft is exposed to open air and can get pretty crusty over time, even a bit rusty. I consider buffing it clean an essential step when doing a seal replacement. Doing this can sometimes even cure minor leaks from an existing seal.
 
Feel like bein' a test pilot Marty? I bought these awhile back when RobinC was having problems with his cam seals. Never got around to trying 'em and seeing how well they'd do.
The inner lip is 1mm smaller dia. than the originals 25mm.
I'll install and test these on my big bore engine eventually... but that's prolly a year or so away.

$3.50 per seal from Oringsandmore.


View attachment 214707
I'll ride the bike and make sure the cavity still fills with oil. Gotta get off my butt and do a bunch of chores first. It's possible that I'm looking at the Vaseline pre-lube that melted.
 
Yes, buffing a shaft clean and shiny with a Scotch-Brite pad before new seal installation is an old mechanic's trick and often helps. Besides removing corrosion it will smooth out minor imperfections, giving the new seal a fresh surface to work upon. And even though the seal lip is just rubber, over time it can start to wear a minor groove in the shaft where it makes contact. The Scotch-Brite pad will smooth this out as well. The end of the camshaft is exposed to open air and can get pretty crusty over time, even a bit rusty. I consider buffing it clean an essential step when doing a seal replacement. Doing this can sometimes even cure minor leaks from an existing seal.
I had no leak until I did the top-end refresh. So, I caused the issue. Everything is better if you don't let the mechanic touch it. I know this on both the grand and very personal scale.
;)
 
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