secondaries not opening 600 holley

[jetsboatsrus]

While running my jet boat with brand new factory set dual 600 holleys on a weland highrise we were doing about 4500rpms and i manually opened the secondaries and it died...the secondaries are not opening at any speed...any suggestions??

 

[Grub54891]

Re: secondaries not opening 600 holley

Areyou shure they arent opening and once up to speed they flop shut? Seen ithem do that before,but still ran fine. Don't know if it's right but it was doing ok. Did you recently upgrade the carb? Some have to be tuned for the application,lighter secondarys ext....

 

[Maclin]

Re: secondaries not opening 600 holley

Are they Vacuum secondaries? Or are they Double Pumper manual? Also, is it a progressive linkage?

Vaccuum secondaires are controlled by a spring. Double pumpers are what they are, have to get close to the right CFM before they work for any given engine.

On vacuum controlled the secondaries should open gradually as engine demand increases. If they are opened manually and too fast a severe lean condition will be produced.

Not sure what engine this setup is on or state of tune it is in, but right now it sounds like it only "needs" about 600 cfm...?