Author Topic: Carb O ring madness  (Read 1143 times)

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Offline david 750f

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Carb O ring madness
« on: April 08, 2007, 12:51:26 AM »
3 O rings came in each carb re-build kit..Two are for the fuel T but I cannot find a place for the third O ring..It is much smaller than the other two, about the same diameter as the metal washer for the screw where a carb sync tool would be attached..

I checked the carb schematic but don't see that small O ring, any ideas??
Thx

I bought Keyster re-build kits for 1976 CB750F.
1976 CB 750F

Offline medic09

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Re: Carb O ring madness
« Reply #1 on: April 08, 2007, 02:18:36 AM »
Drain screw for the bowl?  On the later (77-78) carbs, that would be a possibility.

Remember, if your previous rings are in good shape, they may not have to be replaced.
Mordechai

'78 CB750K
'76 Triumph T160 Trident (rebuilding)
'07 aprilia Caponord

Santa Fe, NM

Offline david 750f

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Re: Carb O ring madness
« Reply #2 on: April 08, 2007, 03:49:47 AM »
Medic09,
why would you not replace the O rings in the fuel T's as they already apart and accessible?? I noticed a difference of opinion in this forum whether to replace everything or just worn items when doing a carb re-build. Re-place or selectively replace??
Thx
1976 CB 750F

Offline medic09

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Re: Carb O ring madness
« Reply #3 on: April 08, 2007, 04:47:30 AM »
There are bigger experts here than me, by far.  I defer to them.  I seem to remember Mike Nixon in one of his booklets commenting that gaskets and such are reuseable.  I found when I rebuilt my 78 750K carbs recently that the aftermarket o rings just didn't fit as tightly as the originals that were already on there.  In the end, my carbs work fine; but I'm not completely pleased that the replacement parts didn't all fit like originals.
« Last Edit: April 08, 2007, 04:51:55 AM by medic09 »
Mordechai

'78 CB750K
'76 Triumph T160 Trident (rebuilding)
'07 aprilia Caponord

Santa Fe, NM

Offline cben750f0

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Re: Carb O ring madness
« Reply #4 on: April 08, 2007, 04:49:33 AM »
mate i have an F1, and used the keyster bleed air screws... big mistake, they are made of brass, and when you put the spring under them , and adjust them, the spring grates off small shaving of brass!!!, its a pain, b/c it gets stuck in the small bleed air gallery, and you have to pull the bloody things apart again to get it out, stick with the factory honda ones, they are made of a harder metal.... just letting you know, otherwise i am with you, if its apart you might as well change the things you cant get to readily.... hope this helps...


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kettlesd

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Re: Carb O ring madness
« Reply #5 on: April 08, 2007, 10:59:46 AM »
There are bigger experts here than me, by far.  I defer to them.  I seem to remember Mike Nixon in one of his booklets commenting that gaskets and such are reuseable.  I found when I rebuilt my 78 750K carbs recently that the aftermarket o rings just didn't fit as tightly as the originals that were already on there.  In the end, my carbs work fine; but I'm not completely pleased that the replacement parts didn't all fit like originals.

A lot of gaskets swell after theyve come in contact with the fuel. May account for why the originals seems more snug.