• Required reading for all forum users!!!

    Welcome!
    Register to access the full functionality of the GSResources forum. Until you register and activate your account you will not have full forum access, nor will you be able to post or reply to messages.

    A note to new registrants...
    All new forum registrations must be activated via email before you have full access to the forum.

    A Special Note about Email accounts!
    DO NOT SIGN UP USING hotmail, outlook, gmx, sbcglobal, att, bellsouth or email.com. They delete our forum signup emails.

    A note to old forum members...
    I receive numerous requests from people who can no longer log in because their accounts were deleted. As mentioned in the forum FAQ, user accounts are deleted if you haven't logged in for the past 6 months. If you can't log in, then create a new forum account. If you don't get an error message, then check your email account for an activation message. If you get a message stating that the email address is already in use, then your account still exists so follow the instructions in the forum FAQ for resetting your password.

    Have you forgotten your password or have a new email address? Then read the forum FAQ for details on how to reset it.

    Any email requests for "can't log in anymore" problems or "lost my password" problems will be deleted. Read the forum FAQ and follow the instructions there - that's what we have one for...

  • Returning Visitors

    If you are a returning visitor who never received your confirmation email, then odds are your email provider is blockinig emails from our server. The only thing that can be done to get around this is you will have to try creating another forum account using an email address from another domain.

    If you are a returning visitor to the forum and can't log in using your old forum name and password but used to be able to then chances are your account is deleted. Purges of the databases are done regularly. You will have to create a new forum account and you should be all set.

Best way to fix camshaft rubber gasket leak

  • Thread starter Thread starter Guest
  • Start date Start date
G

Guest

Guest
Hi,

My bike is nearly ready now, except for one small oil leak (which is probably a TUV failure here in Germany!). I changed the rubber gaskets with a new set but they are still leaking from just below the rubber moon shaped gaskets. What should I do, put some gasket cement on there as well, try another supplier for the rubber gaskets? Any advice?

Thanks for any help

Dave
 
If you are talking it's the half moon rubbers that are leaking when I install then I put a very light coating of blue hylomar around them let it flash off for 5 mins before installing them never had a problem after (if you try to install before it flashes off the rubbers have a tendency to slip and slide out)
This is assuming they are the correct size do they fit and follow the contour snugly and protrude above the gasket face so when you put the cam cover on it compresses the rubber.
 
Last edited:
yes, a little sealant (not so much as to goo out) is fine, even "standard". Some like to install them lip-side in as well, as insurance from blowing them out. I have never felt the need, but....
 
Lip side in might be a good idea, the oil pressure will help them seal better. I'll give that a go, along with some yamabond. Thanks for the ideas.
 
Permatex Ultra Black RTV is my go to gasket sealer. Any that oozes out can be wiped off and it is black so if you miss any you'll never notice it.
6400002.jpg
 
fastbysuzuki said:
It would be a good idea to check your crankcase breather to see if it's clear there should be no oil pressure up there.
Click to expand...

Another good idea, everything looked clean but I'll blow through the hose next time the heads off.
 
Not sure what bike you have but if you are running a standard air box any blockage would likely to be in the vary narrow passages where the breather pipe from the cam cover goes into the airbox this can be checked by disconnecting the hose and blowing down it to see if it's restricted.
 
One thing I've found is that new half-moons often leak because it's very difficult to get them to compress far enough; they stick up a little, creating a gap between the gasket and the cylinder head. You can put a wee tiny bit of case sealer or (horrors) RTV on the corners, but you also have to watch this because it can sort of lubricate them a little and they can squirt out when you tighten the valve cover. Installing them backwards can help, or at least make sure they can't escape entirely.

Anyway... new half moon seals are one of those things that sounds like a great idea but usually end up being a complete ball ache. Re-use the old ones if at all possible.

If not, then do your best and keep a careful eye on them until they squish down a bit and stop trying to escape. I can't say whether there's much difference between aftermarket and OEM seals in this regard; both are problematic.
 
It is a strange design choice by Suzuki, a two lipped half moon would be better (maybe I will make my own by gluing two together). I just wonder what is the purpose of them, why not just make the head surfaces flat?

BTW the breather hose blowed though fine.
 
Last edited:
DaveWatts said:
I just wonder what is the purpose of them, why not just make the head surfaces flat?

BTW the breather hose blowed though fine.
Click to expand...

its to do with the machining process when the camshaft journals are being machined (horizontal boring accross the cylinder head)
 
fastbysuzuki said:
its to do with the machining process when the camshaft journals are being machined (horizontal boring accross the cylinder head)
Click to expand...

Right, but why on earth couldn't they use a seal with two lips?

Never really figured out why this seal is basically designed to fail...
 
Maybe the seal can be helped to do its job with some external pressure. I'm thinking the right sized piece of rubber sandwiched between the seal and the camshaft cover may increase pressure on the other seal. I think I will get some polymer clay and see how big this gap is. Another project I want to do is use some polymer clay to measure the distances within the air filter box and the outer cover. Then maybe I can get a 3D printed rubber gasket made up.
 
greg78gs750 said:
yes, a little sealant (not so much as to goo out) is fine, even "standard". Some like to install them lip-side in as well, as insurance from blowing them out. I have never felt the need, but....
Click to expand...

I got stranded once when one of those seals popped out, so ever since that I've installed them lip side in.
 
New valve cover gasket, new half moons with Yamabond. Doesn't leak a drop. Never had one blow either.
 
You must log in or register to reply here.
Back
Top