Do you recognize this o'ring? seems to me like an air seal, not pressure; found on the left hand side of the Le Mans.

[p6x]

During my pre-ride visual inspection, I found this seal that looks like something that could have fallen from the injection air intake.

This was hanging on the left hand side of the bike.

Anybody has seen one of those and could help me identify its origin? I rode the bike after finding it, and did not observe any change in the behavior.

 

[docc]

@p6x,

Check your dipstick to see if its O-ring has gone missing.

[docc]

(I believe that is too small for anything related to the air intake . . .)

O-RING 17, 86X2, 62

#35: GU90706178

[docc]

@p6x , any luck finding the missing O-ring? I was hoping that post took the prize, but we're not beyond looking further . . .

[p6x]

Sorry, I am not very good at finding the new topics in the forum. I should probably subscribe, that seems to be the only way to know when someone has answered, other than perusing all the topics one by one.

The dipstick was missing the o'ring...

Now, I don't remember having seen an o'ring there ever.

How could it suddenly appear? the top part of the dipstick lid is tapered. I did not see an o'ring groove?

But it is clearly visible on the drawing above..... therefore, I am going to assume it came off out of my knowledge, stayed on the bike? and eventually fell down for me to notice.

 

[docc]

I noticed my dipstick O-ring is compressed into the angular shape and no longer resembles an “O” at all. It would require a pick to lift and and know it is actually there.

[paulnaz]

 

 

 Docc is correct. The O-ring groove you refer to is between the end of the threads and the cap. Once installed it takes on the angular shape of the chamfer on the crankcase.

 

      Paul B

[p6x]

My professional life has been a long succession of o'ring.... different sizes, shapes, material too. High pressure, high temperature, 10 years shelf life, don't expose to UV rays and so on.

o'ring in viton, kalrez, with or without backup rings...

Proper installation of o'ring is an art too. You should never roll them on.

Here's an excerpt from an operating manual I wrote; this one is specific about o'ring....