Holley 750 Carb Question/Issue
Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 948
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From: Johnston Iowa
Holley 750 Carb Question/Issue
I have a Holley 4160/3310 750CFM W/Vacuum secondaries in a 68 Camaro with a built 350 in it. I drove it the other day and when I came home and turned it off I noticed I had a little fuel dripping out of the throttle shaft on the secondaries where it comes through the main body of the carb. I checked the float levels on the front and back float bowls and they were set perfect. I went ahead and took the carb off, cleaned all of the float bowls out, installed 2 new needle and seats, checked the floats and put it back together. Started it up set the floats again and drove it around the block. Came home checked the float levels and checked the carb and everything looked good. No leaks and runs fine.
Took the car out for a run, ran it hard came back home, opened the hood and again I have a little fuel dripping out of the throttle shaft and I can see a little fuel in the primaries too. Checked the float levels real quick and they are still good. I have a new correctly size Power Valve in it also. Could this be an issue with the fuel boiling in the bowls after I turned the car off? It never use to do this that I can remember.
Took the car out for a run, ran it hard came back home, opened the hood and again I have a little fuel dripping out of the throttle shaft and I can see a little fuel in the primaries too. Checked the float levels real quick and they are still good. I have a new correctly size Power Valve in it also. Could this be an issue with the fuel boiling in the bowls after I turned the car off? It never use to do this that I can remember.
Drifting
Joined: Dec 2004
Posts: 1,345
Likes: 3
Boiling fuel is a definite possiblity. I don't think there are any fuel passages near the throttle shafts so perculation is likely. Look at your air cleaner lid to see if there are signs of fuel hitting it due to boiling fuel.
Thread Starter
Burning Brakes
Joined: Nov 2000
Posts: 948
Likes: 0
From: Johnston Iowa
Looked at the bottom inside lid of the air cleaner at it looks clean. Drove the car to work this morning without laying into it and its fine.
I have no idea what the deal is.
I have no idea what the deal is.
Pro
Joined: Sep 2004
Posts: 595
Likes: 0
From: Boston MA
I agree, sounds like fuel boil over.
Try putting a "lars" heat shield under the carb.
Most likely caused by the high percentage of alcohol in today’s unleaded fuel.
The radiant heat under the hood causes it to boil over.
Joe
Try putting a "lars" heat shield under the carb.
Most likely caused by the high percentage of alcohol in today’s unleaded fuel.
The radiant heat under the hood causes it to boil over.
Joe
