Topic: What the Puck?

[billingstitan]

Hey guys - question about the pucks on a 77 CB550 - I've searched the forum but am not quite finding the answer.

I've got an oil leak coming from the top end - sounds like exactly the sort of thing that is described with the aging puck issue.

My question: is replacing these as simple as removing the top end, popping out the old pucks, and putting the OEM replacements, then reassembling?

I apologize in advance if there is an answer somewhere on the forums already, but I could not find it through the search!

[phil71]

Pretty much, yeah. I like to use some hondabond, but new ones are soft, old ones are brittle and cracked from heat. http://4into1.com/vesrah-sealing-rubber-ab-1001-honda-cb500-cb550-cb650-cb750/

[scottanderson76]

Billingstan, I have the same problem and I was told that the pucks are the culprit and new ones will solve the issue.  How bad is your leak?  After riding I usually have it on both sides down to the second fin.  Not a bad leak but it does bother me and I will address mine this winter.

[billingstitan]

Mine's basically the same - the longer I ride, the more drips down - I like to ride to work, so it can wreak a little havoc with the work clothes. I don't seem to lose a whole of oil, at least based on checking the level -

But you know how it goes - I've made things worse more than once by opening up one of these old bikes to "fix" something 

[billingstitan]

Thanks for the reply Phil71 - are there any other gaskets, etc that need to be replaced along with this operation, or is simply pull of the cover, replace the pucks, and get back on the road??

[phil71]

everything labeled 15, and the valve cover gasket

[motosan]

Phil, that's the head from 750.  I think we are talking about 550.

Anyhow, have made sure that it's actually the pucks?  never hurts to throw baby powder at it before ordering parts and taking the cover off....

There could be a few causes.

Tappet hole cover o rings (91302-001-020)
Cylinder head side cover o rings (91319-323-000)
Cylinder head cover gasket (12391-323-000) 
Rubber seals (91318-300-013)

what's the condition of the cylinder head cover gasket?  if that one is bad....I'm not sure replacing the rubber seals alone would solve the issue completely. 

I'd check them in the above order if you haven't done so yet.
 

[dohcdelsol93]

another cool trick is cleaning the bike really well with a degreaser.

Let her dry completely.  Spray the engine in the area it's leaking with spray anti-antiperspirant deodorant.   Then ride.  Every few miles stop and look where the weeps are coming from.

unlike many people here i don't really enjoy working on my bikes...or anything else for that matter since i work on equipment for a living. 

So when I tear into something like that I go ahead an seal everything with new o-rings and gaskets when i go back in there.  I'd hate to repair the pucks just to have some o rings or valve cover gasket start to leak the very next season...or worse yet with the next tank of gas. 

[Bankerdanny]

If you decide to replace the pucks you should just replace all the various o-rings on the valve cover, there's a large one that runs around the perimeter of the cover, a smaller one on the breather cover, 8 on the adjuster covers, and 2 each on the end caps on each side of the head.

All together it's about $20-$25 in o-rings.

[billingstitan]

Thanks - I'll prob go that route - I've already ordered the pucks - but will just try to find the whole shebang before I start pulling it apart I suppose ....

[RAFster122s]

Be sure and use the rubberband trick on all the adjusters to prevent valve or valve guide damage on your 550 when reassembling...