PG
I have a Holley on mine and the ajustment is done with screws.

My buddy is good with Rochester carbs and very good with Vets. He is the guy who restored my Z28.

Vcamaro42769@aol.com
His name is Steve, tell him Jim sent you.

Schoon

 

I think you'll have to put a vacuum on the control valve signal line to port the manifold line to the cannister. That was the problem with mine. The control valve on top was leaking and therefore the manifold never sucked the fumes out of the charcoal.

 

PG,
I just remembered something I read last year about a guy who had a very similar problem like yours with his Vet.
Turns out the gas smell was actually comming from the tank through the gas cap.
He put on a new cap and the problem went away.
Worht a try!

Schoon

 

The spec for the float drop is in the Service Manual. On my '73, it's 7/32" with the needle in the seated position. To lower the fuel level, you'd need to bend it down.

Another possibility is that the float (it's made of foam) has soaked up gas and no longer rides as high as it once did. One of the drawbacks to Q-jets. I'd put a new float in and set the level. Heck, if it's been a while since the carb has been rebuilt, might as well put a kit in and refresh it. Most of the kits have decent instructions and pics.

 

Hi SCHOON, I checked out the lines front to rear and there are no signs of any seepage or leaks.
Like all things on a Vette the Vapor Seperator is totally inaccessible unless you drop the tank. I think 78buckshot found the problem, heat soak after a hot shut down. I kept the email adress of the expert that you mentioned, I also found a site for a rebuild of a Q-Jet and found out that a basic rebuild is not that hard. www.4wheelnoffroad.com/qjet.html so I'll try the rebuild on my test carb and go from there. Thanks again to you and everyone else. PG.

 

That's a great link.

A few cautions that I've picked up over the years: don't place the power piston in the carb cleaner as it has a plastic part on it, when you push the accel. pump pin towards the air horn, it's a good idea to place something thin behind it so you won't push against the air horn which makes it hard to push back in the lever, be careful when re-installing the filter nut as the alum. threads in the carb body won't take a lot of torque (if they do strip out, you can get a special filter nut that has threads that go deeper into the carb and catch undamaged threads), a new float isn't in most kits and has to be purchase separately, and the carb cleaner does come in one gallon cans which will do several carbs. Good luck, it's not as hard as it seems at first.

 

HI 73shark, Ok my float drop is listed as 1/4" with main jet at 75.
and my main rod is listed as a 46. I want better milage, should I get a smaller or bigger main jet or a smaller or larger main rod, or both? PG.

 

This may sound very basic, but have you checked the seal on the gas cap? I had a similar problem with gas fumes in my garage. Idiscovered that the gas cap wasn't sealing properly. I put a new on and presto...
no more fumes.

good luck

 

PG,
I will bet you a lunch it's the gas cap.

 

Ok SCHOON and orangevette you both talked me into it and since the cap is 35 years old I need a new one anyway.

I had major fumes today, I went to siphon a gallon of gas out of the vette to fill the gallon can for the lawn mower, didn't pay attention and over filled the can. WOW! That was a mess. Wiped up the spillage and washed the car, I'll mow the lawn tomorrow. PG.

PS, I hope I owe you lunch.