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Discussion Starter #1
I have an early style head on my CL77 with the vent ports next to the carb intakes. I am getting close to fire up and really can't find a definitive answer as to whether to run tubing from the these ports, or just leave them be. Thanks in advance for any input......
 

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Britman,
Those vent ports were originally connected to the air filters with a flexible tube. These vents went into the intake valve guides, I think the purpose was to lessen the chance of oil being drawn into the intake port between the valve stem and the intake valve guide because of the negative pressure created in this area while the motor was running. As you seem to know, eventually Honda eliminated them from the head during the last years of production.
If you were doing a full restoration and your stock air filters have the small tube on the front of the filter then add the rubber hose to each side, it will at least look correct.
I just checked my two Super Hawks. My Cafe bike (which was assembled from many donor bikes) has the newer head without the vent ports. My new-in-the-crate, close to stock bike has the vent ports that are not connected to anything. They have been that way since at least 1969 when I installed Honda 450 Black Bomber carburators on it. That means that I've probably rode it approx. 15 to 20 thousand miles without the vent ports connected to anything.
If you are concerned about getting dirt in then you could run tubing from one vent to the other.
Mark
 

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Discussion Starter #3
Thanks Nebraska for the input. I am certainly not concerned with a full restoration look since those style air cleaners are no longer to be found and I am not interested in drilling any extra holes in my new reproduction set. I am inclined to just run vent hose from the ports and exit down the rear of the motor. I know it would be fine without doing anything, but a little extra tubing won't hurt......
 

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Some people remove the nipples and block the ports with short bolts.
 
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