4.3LX Vacuum gauge hook for Air/Fuel mixture

[Jnones]

Guys,

I want to adjust my fuel/air mixture and lower the idle RPM ( current at 950-1000 using a laser tachometer) but I cant figure out where to hook up the vacuum gauge, I look everywhere and I can find anything, if I'm not wrong I suppose to hook it to the manifold but I'm not sure exactly where, can you guys guide me?

1995 Vortex 4.3LX V6

 

[Bondo]

Ayuh,...... Welcome Aboard,....... Most boat motors don't have vacuum ports, as most times boat motors have very little vacuum available,.......
The throttle plates are most often Open,.....

I had that same motor, 'n tuned that carb, by ear, 'n spark plug color,.......

That's a Great carb, exact copy of the Edlebrock 1409,....
Edlebrock parts are cheaper, 'n easier to get, than anything from Merc,.....
The on-line tech manual at Edlebrock, is the Bible, for that carb,......

 

[dubs283]

I suppose to hook it to the manifold but I'm not sure exactly where

there's a couple 1/4 pipe plugs in the manifold, one front, one rear. either should be fine to remove and install a barbed fitting for your gauge to adjust idle mixture and idle setting

once set, reinstall the plug

 

[Jnones]

dubs, I will have to remove one of those 1/4 plugs and see what threads they are and buy a fitting, thanks for the help.

bondo, thanks for the inside of the carb I will look for that manual as I'm not sure where the idling timing screw is located.

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