Topic: CB400f Cylinder and Head Reassembly

[Ernest T]

I don't remember an o-ring here and I didn't get one in the rebuild kit, but it looks like one is supposed to go in this space.  Are there any o-rings between the case and the cylinder?

[stickfigure]

Ernest, unfortunately I don't have an answer for you. I'm curious, however, which gasket set you got for your bike.

I need to fix a leaky top end on my 400f and I've been reading mixed reviews of all of the after market gasket/ o-ring sets.

[Ernest T]

it's a Vesrah.  They have a pretty good rep.

[Ernest T]

Another question.  Between the 1st and 2nd  and 3rd and 4th valves, the stud has an extension on it instead of a acorn nut.  It takes a bolt which holds down the rocker assembly.  Underneath the extension is a washer which is completely rubber coated on one side and only partially rubber coated on the other.  My originals were black and covered with gunk and I didn't realize it wasn't the same on both sides.  Anyone know which way it goes?

[stickfigure]

Thanks, Ernest.

[MoMo]

Most Honda head washers have a chamfered edge on one side-that will go up.  The washer you are referring to has the less covered side up...Larry

[Ernest T]

Thanks.  I'm pretty sure there isn't an o-ring between the case and cylinder.  I plan to torque everything down this week.

[magconpres]

No o-ring where the stud comes through.
The only seals between the cylinder and the head are the ones around the oil orifices and the dowels in the front corners, and of course the head gasket.
Verified with the parts diagram.

[Ernest T]

Thanks, I got the head/cylinder connection, I was concerned about the cylinder/case interface.

[jessezm]

Ernest, there are no O-rings there--it just looks like that gasket is cut a little loose around the stud.  Only thing between the cylinders and case are the two locating dowels on either end.  And don't forget the 4 large rubber o-rings that go around the sleeves themselves and sit up in that recessed groove on the underside of the cylinders.

[Ernest T]

Ernest, there are no O-rings there--it just looks like that gasket is cut a little loose around the stud.  Only thing between the cylinders and case are the two locating dowels on either end.  And don't forget the 4 large rubber o-rings that go around the sleeves themselves and sit up in that recessed groove on the underside of the cylinders.

Thanks, I dang near put it together without them.  Luckily I got smart and put it all together with all the o-rings and gaskets and saw the four big ones left in the bag before I installed the acorn nits.