holley 3310-4 secondary not opening

[man-of-war]

What would stop the secondeary from opening? We tested the diaphram by creating a avacume[by mouth] and noticed the diaphran's arm moveing up and staying up as long as we kept vacume. even at short high rev it would not open .all the links are free for every thing to move .thanks

 

[Buttanic]

Re: holley 3310-4 secondary not opening

On the left side there is a mechanical linkage that connects the primarys to the secondaries. If the primarys are closed the secondaries will not open no matter what the vacuum is. As the primaries open the linkage will let the vacumm open the secondaries as needed based on engine load. Actually vacuum does not open the secondaries it holds them closed. When the vacuum drops as load on the engine is increased a spring in the vacuum pot opens the secondaries. This spring can be changed to stronger or weaker one to tune the point at which the secondaries open. Just reving the engine will not open the secondaries as there is no load on the engine that would call for the secondaries to open. It is best to have a complete understanding of how the carburator words before attempting to make changes. or troubleshoot it.