View single post by James Sohl
 Posted: 02-04-2013 06:45 pm
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James Sohl


Joined: 04-24-2006
Location: Chandler, Arizona USA
Posts: 18
The distributor vacuum diaphragm is for retard on overrun.  On the left carburetor, there should be an attached vacuum controlled valve that applies manifold vacuum to the distributor on high vacuum, i.e. overrun.  It is purely an emissions item and the engine will operate fine without the vacuum retard.  It is important to make sure that all overrun vacuum connections are carefully, completely blocked if you remove the plumbing.  I know, I know, most distributors have a vacuum advance, just not all distributors.
Regards, Jim JH sn 11210