Intake O rings

mizike77

Junior member
Hello all,

I am chasing lean conditions on my 1200. Spraying solvent around the intakes results in quite a change in running. So, the first thing to change will be the orings on either sides of the intake insulators. They look to be  P/N 55 130 037 
Does anyone know the size of these when new so I can attempt to find them locally or in my stash of Japanese bike parts ? Or is there a known equivalent ? 

Thanks-
 
You missed out the vital reference, but which is kindly supplied by i fratelli Laverda.

OR 3150.
=
37,77 x 2,62.

Check that makes sense first, nat'.  But seems to be widely available  :).

HTH.
 

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Just to add to the confusion. I used some viton "O" rings 40.94x2.62 on my 3C. Fit was just fine. AIRC it is an imperial size "BS130" and is snug in the groove(s) .29 cents each USD. you need six. I think your 1200 has the same carb mounting.

Do check and replace those phenolic insulator blocks if there is any doubt. They will crack with age. Andy had them at about 19 euros each a couple of years ago.

https://www.oringsandmore.com/ here is the USA or get BS130 viton O rings nearby.
 
please also check the manifolds are still flat. Many of them tend to bend towards the head at the ends where the bolts go through causing a curved surface with 1mm or more difference between center and edges easily. They need to be fully flat. If not, you can try to solve it on a lathe. However, that might make the issue bigger, as the O-ring then comes out of the grove it sits in even more and while fastening the manifolds to the head, you bent them again. I had that just before Christmas on a 1200 and only checked due to a hint of a friend of mine.

Best solution: buy some new billet ones from Red.
 
Rusty Spokes said:
Just to add to the confusion. I used some viton "O" rings 40.94x2.62 on my 3C. Fit was just fine. AIRC it is an imperial size "BS130" and is snug in the groove(s) .29 cents each USD. you need six. I think your 1200 has the same carb mounting.

Do check and replace those phenolic insulator blocks if there is any doubt. They will crack with age. Andy had them at about 19 euros each a couple of years ago.

https://www.oringsandmore.com/ here is the USA or get BS130 viton O rings nearby.


To double check before ordering-
I am seeing the BS130 as 2.62 x 40.94 ID x 46.18 OD which does not seem to match the drawing that was posted.
If I were to match up  the dims provided I would be looking at the BS128 2.62 X 37.77 ID x 43.01 OD

Sizing chart here : https://www.allorings.com/British-o-ring-Size-Chart
 
Can you not simply measure the diameter of the groove in the isolators to tell?  The 3mm difference in the diameter of the two sizes should be apparent enuf, I'd have thought?  And if the big ones are too big, you can always cut them, snip off the excess, and glue the ends back together.

But, if any doubt remains, do as per Rusty: Order up both sizes.  (I say that in the hope that half a dozen of each ain't gonna break the bank .. ?) :eek:

 
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