GAV vibrating closed

ScottNW/Ohio

Senior Member
Just got home from a 60 mile 'shakedown' cruise in 31 pickup.
I noticed it was starting to heat up on me, (190/200 - no thermostat, 50/50 coolant premix) while bucking a headwind, I looked over and my GAV knob was almost closed (was set between 1/4 - 1/2 open) I opened it back up and a few miles later, it was closing up again...any ideas on preventing this ?

It's got new hardware (new GAV, new return springs, etc)
It's a Zenith carb - it came with the truck in a box of parts - I put a rebuild kit in it and put it on. Truck had a Tillitson on it when I got it.

Other thing I noticed, when idling, the engine speeds up when I close the GAV - other than that, it seems to run OK, idles smooth, doesn't hesitate or backfire.
(fresh rebuild, manifolds have been plained and true, no vacuum leaks or smoke)
Thanks
 
Put a drop of blue locktight on the threads of the GAV that should do the trick. When you are running the car the GAV is to be adjusted as closed as you can and still have the engine run well.
 
The brass GAV thingy that screws out of the carb is supposed to have a small wire circlip on the pointy end to apply tension, is it there? Bill W. (The one with the pointy head!)
 
Bill,
I'll check for the circlip on the GAV

So - then I was maybe 'wrong' to blame the GAV for the heating up??

I thought maybe I was 'leaning out' too much - and causing it to heat up.
It's been running 180 - 190, I've only driven it about 140/150 miles, I'm breaking it in slowly (and it's breaking me in too:rolleyes:)
 
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