[Guest]

When the car is out of gear it rev's just fine. No spit,bog just nice and clean. When I drive it and step on it, I get a bog. The carb is a 750 holley double pump,dual feed with mechanical secondaries. The jets are 76 front 80 rear with a plug in the power valve position. I'm wondering if the plug is causing the problem. The guys at the track said to use a plug and up the jets by a few sizes. What do you think? The float levels are fine and the accelerator pumps are set. The shooters are 28 front and 37 rear.

 

[Guest]

try putting in larger shooters. im not the best at this kinda stuff but i was reading about it and that was the first thing recommended for double pumpers. they say the bog is due to a temporary lean condition. i have a holley with vac secondaries and had the same problem. fortunatelly all i had to do was adjust my accelerator pump with a wrench and now its all cools.

Corpus Christi TX

 

[Billgear]

I'm no carb expert, here are some good websites that might help.

http://www.bob2000.com/carb.htm
http://www.geocities.com/MotorCity/Track/3553/Tech_Briefs/carbtuning/carbtuning.html

Regards,
BillGear

1966 Mustang Coupe, 302 custom roller cam, holley 650dp,http://www.289mustang.com
http://www.289mustang.com/images/vmfcar.jpg

 

[Hottarod]

What stall and gears are you running? Do you have jet extensions on your secondaries? If you are launching hard they could be uncovered and are basically dry when you launch the car.

A power valve can sometimes help mask the dp pop and stumble if you are running out of secondary pump shot. This is because the power valve pops open and richens up the primaries a little when you stomp it to the floor. Another thing that will help is running as much initial timing as you can and putting in your advance quicker. A 50 cc secondary accelerator pump is pretty much a given with a 37 shooter.




You can see my 65 fastback at: http://hottarod.stangnet.com/
http://members.aol.com/macstang/Gifs/macstang3.jpg