Crank case O ring size.
- Thread starter Paul Marx
- Start date
I have the 1200 parts book. Item 9 on drawing 2, O ring on left side of lower crankcase half is listed as OR121. Putting that into the worlds best known search engine gives an O ring size 15.88mm x 2.62mm. I have used this to identify other O rings in the parts book, it does seem to work.
Thanks. I'll have a look.
OR121 indicates an interior diameter of 121mm.
There can be several thicknesses. For instance
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If you look at the photo in Andy Wagners catalogue, thickness would appear to be 2mm.
Paul
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I double checked and very strangely, the O ring figures as you mention in the 1200 parts list, but not the other models.
I'll measure the depth of the recess in the case mating surface.
Paul
2mm width may give enough extrusion to seal the oil pump outlet, the pressure isn't very high. 2.62mm will definately be enough.
www.instality.com
Have a look at this website.
O-Ring size 15,88 x 2,62 OR 121
Instality.com allows you to buy the MGFTools original spare parts. O-Ring for MGFTools testing pump 120bar. Size: Ø 15,88 x 2,62 mm Ref. OR 121for faucet repair
Here is another example, OR 2021. These are the fork oil drain O rings. The numbers do not seem to relate to the size of the O ring.
OR 121Here is another example, OR 2021. These are the fork oil drain O rings. The numbers do not seem to relate to the size of the O ring.
breganzane
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No, OR121 is a specification which includes internal diameter and cross section, in this case 15.88 x 2.62. There are a heap of different oring sizing standards, quick googling does not find where the OR designation comes from - likely an EU or IT standard I guess.
Here in the colonies here most oring shops will know the BS standard (often just called 'dash') and also standard metric sizes. The closest would be a BS114 (nominally 15.54 x 2.62), or I guess a 16x2.5 would work also. I expect in Europe any decent oring supplier will know what an OR121 is and can supply it.
Eurocycleguy
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- Chicagoland-USA
I've heard about the BS standard before. 
I beg to differ Steve.
I've been looking this up since I initially had no answer to my query.
121 is the diameter in mm multiplied by 100. See the diagram given by a supplier.
That will be followed by the thickness of the ring, for instance OR121x2 in my case since I need a 2mm section. Then you add the material the ring is made from.
So, OR121x2 is a ring of 12.1mm diameter and 2mm cross section.
I very much doubt that this standard has anything to do with the EU.
Paul
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The dipstick O ring is also listed as a OR121 which does make it the same. The 16x2.6 dimensions are almost the same as the 15.88x2.62 dimensions and may be just how they are listed. There are many standards of O ring, BS Imperial and metric as well as French and German standards. It is not likely that these listings have different specifications with the same reference number otherwise anything could turn up.
15.88 x 2.62 is actually an imperial size, it equates exactly to 5/8" x 3/32". 16 x 2.6mm is pretty damn close and will work fine.
O-rings are pretty flexible in regard to sizing, pun not intended.
The OR standard as shown in the parts books seems to be either an old italian standard or a manufacturers code. In any case, the numbers bear no resemblance to the actual dimensions.
Paul, fitting a 12 x 2mm o-ring in this case is a sure failure waiting to happen. The correct 16mm o-ring will fit snugly in the cavity in the lower case.
piet
O-rings are pretty flexible in regard to sizing, pun not intended.
The OR standard as shown in the parts books seems to be either an old italian standard or a manufacturers code. In any case, the numbers bear no resemblance to the actual dimensions.
Paul, fitting a 12 x 2mm o-ring in this case is a sure failure waiting to happen. The correct 16mm o-ring will fit snugly in the cavity in the lower case.
piet
I beg to differ S.
I've been looking this up since I initially had no answer to my query.
121 is the diameter in mm multiplied by 100. See the diagram given by a supplier.
That will be followed by the thickness of the ring, for instance OR121x2 in my case since I need a 2mm section. Then you add the material the ring is made from.
So, OR121x2 is a ring of 12.1mm diameter and 2mm cross section.
I very much doubt that this standard has anything to do with the EU.
Paul
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Thanks Piet,
So, as you say, the OR121 denomination in the Laverda parts list is likely specific to the Veneto.
I shall choose one, or more, of these.
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Joint torique passage d'huile carter moteur Laverda 1000 et 1200 - Crankcases oil passage o-ring - JLO Tech
Joint torique passage d'huile carter moteur Laverda 1000 et 1200 - Crankcases oil passage o-ring
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123 roulement is the place to go for seals, bearings, O rings, bushes, what have you..Another supplier of these O rings. A bit more expensive than the website listed above.Joint torique passage d'huile carter moteur Laverda 1000 et 1200 - Crankcases oil passage o-ring - JLO Tech
Joint torique passage d'huile carter moteur Laverda 1000 et 1200 - Crankcases oil passage o-ring
Same day turnaround, it's 3 km from home and the young ladies are charming.
And they'll ship worldwide. Not the ladies though, they stay local.
Paul