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Carb question - what is this for
Banana - 13/4/17 at 09:17 PM

I noticed the diaphragm seems to be pinched on one of my carbs around the area highlighted in the picture.
What does that hole/jet do?

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r1_pete - 13/4/17 at 10:15 PM

Long time since I worked with cvks but Im sure its the vacuum port which raises the diaphragm / throttle slide.

dd1972 - 14/4/17 at 07:03 AM

quote:
Originally posted by r1_pete
Long time since I worked with cvks but Im sure its the vacuum port which raises the diaphragm / throttle slide.


Spot on as this man says.

britishtrident - 14/4/17 at 08:23 AM

Yes a depression port it has the same purpose as the holes in an SU or Zenith-Stromberg CD piston.

Banana - 14/4/17 at 08:38 AM

Thanks guys, the Haynes book doesn't actually make any reference to it.

Im hoping that is the cause of the hesitancy at full throttle im getting..

r1_pete - 14/4/17 at 11:03 AM

If there is any leak around the diaphragm seal you will get poor running, I used to put a layer of ruberlube in the recesses where the bead seats, keeps the rubber supple, and has a slight swelling property, so ensures a good seal, and makes future removal easier.