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Discussion Starter · #1 ·
Hi all, great forum which I am new too.
Can someone help with small matter of additional O-ring in OEM Carburettor Gasket Set?
I have two Gasket Sets, two additional small O-rings, about 2mm thick & 5mm outside diameter, virtual duplicate for the ones in the "Air cut-off valve assembly", but not I believe these.
Vehicle Model is a CX500B, with VB36A Carbs. I have a Haynes Manual, Figure 3.2 exploded diagram identifies the offending O-ring as items No. 36 in the general vicinity of the Float Bowl Assembly.

Equivalent O-rings did not come out of the carbs when I split theme, so where exactly are they supposed to go. I did think they might be something to due with the Float Needle Valve, but the describing text talks about mating surfaces here so most likely not. Does anybody have any knowledge or experience regarding the offending part or due I just leave them out?

The bike is a find and no I have not had it running yet, but very much looking forward to.
Many thanks in advance
BH
 

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Are they just a bit smaller than those for the fuel crossover tube?

If so, they may be for the crossover tube for the accel. pump on a US model.

EDIT Sorry, brainfade. O ring sizes are normally given as inner diameter x material thickness.

What you have there are the 3 x 1s for your mixture screws.

On further thought they may be for the floatbowl drainscrews.
 

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Discussion Starter · #3 ·
Quite a bit smaller half the size I would suggest. UK model so do not have the Accelerator Pump Assembly.
A very good thought, where/how does the Accelerator Pump Assembly, (APA) actually fit, inside or onto the outside of the Float Bowl? I can see that the APA has a diaphragm valve, is there also a small O-ring as described.
If so you know your stuff very well Sir and i'll get back on with the build.
 

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Discussion Starter · #5 ·
O-ring, 2mm + tall, 1.5mm + thick with about a 3mm + internal diameter. Have already replaced/substituted the float bowl drain screw & mixture screw O-rings. This is a chunky 2mm + thick band type D-ring
 

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Discussion Starter · #7 ·
They perhaps give you one of these D-rings in the OEM gasket repair set, but provide no air cut off diaphragm.
Item still shows as additional in the Haynes exploded diagram, (item No. 36) & hence the frustration. I'm going to pursue your accelerator pump assumption, see if I can find some assembly photos/diagram for those.
 

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Discussion Starter · #8 ·
US Models Accelerator Pump Assembly - "small gaiter at the carburettor body end of the operating rod" and therefore surplus to UK/EU model requirements.
Thanks CXPHREAK
 
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