Topic: CB400F head gasket: what is the best source?

[Alaxy Galaxy]

My 400 has stared leaking enough oil from the head gasket that it's become a real problem. Mostly on the left. I lose about a 1/2 liter (and ruin a set of pants) of oil during a 100km ride.

I've read most of what I can find here and am aware that I need thicker o-rings for the two oil passage bolts. But I'm wondering about where to source a gasket. From what I've read, Honda never offered the original asbestos-ladden gasket for sale (that's probably a good thing). But what about the old, unused Honda gaskets found on eBay? Could they still be any good? Would I be better off with something like a Vesrah? Or, I could make my own copper gasket.

I'm not asking for a perfectly oil seal either. I hear that that's almost impossible.

[claudio.fauni]

I replace the Honda gasket with collars and fkm orings. Stop leaking

Check out in the cb400 four facebook group

Inviato dal mio SM-A750FN utilizzando Tapatalk

[Tim2005]

Does Honda no longer sell the top end gasket kit? They always were better than pattern ones, and I'd certainly be happy to use an old stock one. If not there are plenty of pattern ones around- all of which are fairly good I think. As for the oil passage seals, they aren't really an o-ring, they are a shaped seal, the Honda ones were always better, some of the pattern kits just even included a small piece of tube with no shaping. Part no for that is 12910-333-000  - google image search it & you'll see  the shaping

[bryanj]

If you remove the head you are asking for trouble if you dont replace the base gasket,and o rings, as well

[jonda500]

I've never seen a bad oil leak emanating from the cylinder base gasket? I have removed my head 3 times and even though the base gasket got torn from accidentally lifting the barrels when I tried to remove the head with a little bolt still holding it on, I still haven't noticed oil leaking from there. (It doesn't 'leak' but will probably slowly seep out given enough run time though)   
John

[Alaxy Galaxy]

I'm going to try and find a genuine honda part. Where should I measure gasket thickness? And where can I find those rubber rings in a thicker size?

[bryanj]

Hondaman had O rings for 500/550/750  but dont know size for 400 or if he has them