To lube or not to lube

[Sixgunluvr]

Just starting to put my bike back together, I see on a vid on you tube where Vaseline was used to slightly moisten the carb intake o rings… is this ok or should I just put them in dry if I don’t have anything else?

[Mooskee]

Installing O-Rings
The Honda Maintenance manual simply says, "Install new O-rings into the intake manifold grooves."
Since mother Honda chose to put the grooves on the Intake manifolds instead of the heads, it should say
"apply anti-gravity solution to the O-rings and insert in the intake manifold." A bit of some kind of “goo” to
hold them in during installation certainly helps. I use Dow Corning O-ring lube, or Dow 55 High Vacuum Grease
that I happen to have on hand. Others use anything from Vaseline to RTV. I prefer something that will not dry
and break off into the engine. Thus, something like Vaseline will work as it will simply melt and then burn off.

[Sixgunluvr]

There was no need for any “goo“ during installation. So I guess I’m good. Just wanted to make sure you weren’t supposed to add something just so I’m good with nothing.

[WintrSol]

Except Vaseline attacks rubber, so may damage the O-rings over time. I use silicone grease or red grease, depending on where it goes.

[Mooskee]

Except Vaseline attacks rubber, so may damage the O-rings over time. I use silicone grease or red grease, depending on where it goes.

True, however the reply I sent is an excerpt from instructions for Viton O-rings I sell. I should have clarified for Nitrile O-rings.

[Sixgunluvr]

So I don’t HAVE to lube the o rings? I’d really hate to have to take everything apart again.  I had no issue installing them in the intake tubes and surfaces were cleaned.

[rug_burn]

So I don’t HAVE to lube the o rings? I’d really hate to have to take everything apart again.  I had no issue installing them in the intake tubes and surfaces were cleaned.

No, if you already got it together, you don't have to take it apart again.  And as far as the danger of petroleum based grease being bad for the o-rings:   It is not bad for Nitrile aka Buna-N or NBR o-rings.  I used to design all kinds of valves and fittings with many o-rings.  Nitrile rubber is compatible with nearly all petro-chemicals.   EPDM rubber, the other main type we use is not.

If you're ever in doubt check the Parker-Hannifin O-Ring handbook, available on line.