| I do not believe it is quite that simple to create a vacuum port, but I 
do not really know.  However, the first thing I would do is map the 
advance curve without the vacuum, and then with the vaccum to see if you 
can get an idea what is happening.
Trevor
Phil Nase wrote:
>I've been researching my overheating problem.  I came across an article by
>Paul Tegler where he describes vacuum being pulled from the balance pipe
>rather than the carb port.  From what I understand this can lead to incorrect
>advance.  Very possibly the cause of my hot engine.
>
>My understanding is that if the vacuum unit on the dizzy points away from the
>dizzy the vacuum should be from the carb.  My carb port is plugged so I want
>to drill it out and attach the vacuum line and plug the balance tube cap where
>the vacuum line is now.
>
>I have 1.5" SUs and the hole I want to open is on the rear SU just behind (on
>engine side) the top of the butterfly where it opens away from the top of the
>carb.
>
>My question is... does this sound like I am opening the correct hole on the
>SU?  Also should there be a fitting on the carb to hold the vacuum pipe or can
>I just epoxy the pipe directly into the carb and should I fit the pipe just
>flush with the inside of the carb?
>
>As always thanks for all the help.
>Phil Nase
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