Gasket brands, are they all the same? Recommendations for CB750 DOHC...?

[Snickare]

I can see that happening if they get clogged, but the breathers are just wet, they seem to still work just fine as I check them. And my motor has never overheated. The bike has always been well taken care of, and the oil light has never been activated.

 

[Snickare]

Before this tear down, I had run 10w40 full synthectic. Then after 300 miles, my mechanic suggested I switch to a partial synthetic as it would help the rings seat during break in, and maybe lessen the leaks. So I switched to 20W50 and put another 40 miles on it. That's when it started to leak so bad I couldn't ride any longer. The motor has a grand total of 380 miles so far.

 

[Snickare]

I just bought new Viton Valve Seals off E-Bay. Gonna try to replace the Athena Valve Seals with these new Viton ones. I've read online that they are better than the plain rubber, but still can't seam to find much info on them. Anyone have any experience?

 

[xb33bsa]

Viton is better
your leaking problem is nothing at all to do with choice of oil unless MAYBE if you added a few quarts too many
my guess is gasket surfaces were filthy with big chunks left on them

 

[Snickare]

I'm guessing it could be a combination of just about any of the little details, on top thin, dry aftermarket gaskets. My mechanic said he decked the head, and was meticulous on the rebuild. We'll see how it goes the second time with stock gaskets, and viton valve seals.

Here's a couple pics of how it looked going together the first time. Pics form my mechanic.

 

[teazer]

Copper gaskets are hard to seal effectively. British twins used them for ever and that was on a simple head shape. They work on some motors and others just never seal effectively with copper.

Cometic make good gaskets.

 

[Snickare]

Just got the Stock head gasket in the mail today. There is a pretty huge difference between the Athena Gasket and the Stock one. Here's a pic:

The stock gasket is MLS and coated around the Galley. The Athena is paper with metal rings around the combustion chambers.

 

[YogiBear]

how are the gaskets holding up?

 

[Snickare]

So.

The Athena gaskets are deffinitely thinner and less quality, The Athena vale cover gasket requires RTV. Which is annoying, becasue then you never want to take off the valve cover, because of how messy the job is gonna be. The OEM gaskets have held up great. They ended up being the way to go.

Unfortunately I've had a piston seizure due to a failing oil pump, so now I am in the process of another rebuild... I'll have another report on gaskets when I can learn how nice the OEM head and base gaskets are to re-use.

As for other parts of the motor, alternator gasket, Clutch cover gasket... They work just fine, even putting them on dry. However the shape is not precise. They stick out from under the covers in some places, but not all... They are pretty poorly shaped.

Overall I will use them again where they are applicable and not vital. But go the extra $$$ and get OEM head, base, and valve cover gaskets.

Hope this helps.

 

[Hoosier Daddy]

Just a few "FYI's" to go ito this older thread...
Mother Honda still has Gasket set A available, Gasket kit B is discontinued but the individual gaskets that were in the kit are still available. I bought it from the local Dealership for my '81.
Also, it was a little vague in the Factory Sevice Manual but there are o-rings that go on with the base gasket around the cylinder studs. #14 on the exploded view