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Question about the PD42B Carb on my 78 CB750

mroussetos

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Notice the hose circled, towards the bottom you will see another circle. Someone put in screw to plug up this hose. Does anyone know why they would do that? Also is this called the overflow hose? Please help. I'm trying to identify why someone would do this. This hose is directly beside the PETCOCK valve hose that connects to the tank.

Thank you for responding.:D
 
The other hose coming off carbs besides the fuel supply hose is the overflow or vent line, it MUST be open when bike is running or carbs don't vent and then they don't feed fuel. It comes off the carb at the highest point and all 4 carbs should be joined to it by the between carb joiner hoses.
 
Thanks AMC49. In this case, you suggest removing the nut that is blocking and run that hose all the way down and nest it close to the other 4 float bowl drain hoses? I'm sorry if I'm not reading your response correctly. Right now it won't even reach down there. You can see they cut that hose and added a screw.
 
You can do that if you want, the main thing is that hose must be left open or the carbs don't vent to flow right.
 
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