Topic: CB 350f engine rebuild question - Are cylinder spigot rings necessary?

[cb350f]

I did the head gasket and the kit came with 4 cylinder spigot rings, but i don't remember taking any off when i removed the head. From what i could see there was way to much space between the cylinder spigots and the lower end, i don't think the rings would have been compressed, thus were more likely to just fall into the crankcase. The head gasket should be more than enough should it not? Suggestions from anyone familiar with this engine would be greatly appreciated. It made sense at the time, but i hate not following the manual. I'm reusing rings so i would really rather not take it back apart. (Its not fully assembled yet so no compression test.)

Thanks in advance to anyone that replies.

[camelman]

At this point, run it and see.  I replace them on 400F and 350F engines because they are usually plasticized if they are original.  I have no idea what they seal, and can't see what they clamp to, but I assume they are there for a reason.  Maybe to seal against leaks between the sleeve and the jug?

For what it is worth, the originals definitely sit flush with the lower clamping surface, so it looks like they contact something.  I say this because the new rings sit proud of the clamping surface, which leads me to believe that they contact something to create a seal.

Camelman

[HondanutRider]

Are you referring to the large O-rings that sit around the lower portion of each cylinder.  This is shown in the parts manual page as item #9.

[cb350f]

Yes that's the one. I didn't remove the old ones, like Camelman said they sit flush, and it was not leaking before i started the job. There is a lot of clearance around the cylinder spigot and the wall, so i don't thing they would be compressed. I was kind of hoping someone that races or use to race these bikes (i.e. a lot of rebuilds) had figured out their worth. I will strip the engine again if i must but i would really rather not.

Thanks again for the replies.