Holley 750 help
Thread Starter
Instructor
Joined: May 2006
Posts: 195
Likes: 1
From: Mooresville NC
Holley 750 help
I have 2 750's on a tunnel ram on my Chev 350 in a Rat Rod 49 Ford F3. My trouble is that on the front carb gas drizzles from the venturi at idle and causes a real flooding problem. I installed a gauge and regulator and set the pressure at 4 1/2 lbs. New floats and needle and seats didn't solve it either. By the way I.m using the primaries only, the secondaries are disconnected on both carbs. Stock short block with 1.94 400 SB heads, 480-480,292-292 hydraulic cam.
I seem to remember being told by Baker Carburetors to drill a .100 hole in each primary throttle plate but I can't remember what that fix was for.
Anyone sharp on thes that can advise me, I really appreciate the help.
Rich
I seem to remember being told by Baker Carburetors to drill a .100 hole in each primary throttle plate but I can't remember what that fix was for.
Anyone sharp on thes that can advise me, I really appreciate the help.
Rich
Le Mans Master
Joined: May 2002
Posts: 5,446
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From: 10.70 @ 124mph, Stock Bottom End @ 3620lbs, ECS Racing Team Member. The 1st NMCA LSX Index Rumble World Champion. 2011,12,13 Champion
Have you check the float level? There are two screws on the right side of the carb. Remove the screws while the enging is running, You want the fuel to JUST trickle out at idle. If the fuel is flowing out at a high rate you need to lower the float. The tools to lower the float would be a 5/8 wrench and a large screw driver. Loosen the 5/8 nut and the turn the screw clockwise to lower the float level. 
Thread Starter
Instructor
Joined: May 2006
Posts: 195
Likes: 1
From: Mooresville NC
Thanks for the advice, but that is basic Holley adjustment. I guess I forgot to mention that the float levels are set. I have covered all of the simple stuff and am looking for an answer to what is to me a "freak problem"
I found the problem today, the vent tubes were clogged solid with what looked like beehive dirt. Anyway I cleaned them out thoroughly and it's working properly.
I found the problem today, the vent tubes were clogged solid with what looked like beehive dirt. Anyway I cleaned them out thoroughly and it's working properly.
Last edited by Racer-rt; Oct 12, 2007 at 07:34 PM.
Safety Car
Joined: Apr 2004
Posts: 4,532
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From: Lahaina Hi
You can also get dribble when the 2nd dary throttle plate is not sinked with the primary throttle plate.The little screw in the throttle plate that is upside down and you can only adjust it if you remove the carb or buy the holley kit so you can set up the secondaries like a 4500 carb.
