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Author Topic:   Carb jetting?
Racer64
Dirt Full Roller

Total posts: 26
posted June 23, 2002 02:25 PM
I ran a very dry slick track last night and when I was going through the corner at about half throttle(only in primarys) the motor would sorta pop or blubber. I am wondering if I need to jet up or jet down to sure this. I am running a 383 in modified on alcohol. It has a 750 carb from Speedway. When at wide open throttle the pop or burble disappears. Runs around 190 degrees do I dont think I am too rich. I have 91 in the front and 92 in the back. The carb was done for Speedway by Hardcore Racing Ent. Ran fine on my 406 at the beginning of the year. Had to jet up for this motor though because of better heads.

Any help would be appreciated.

Thanks

dirtbuster
Dirt Freak

Total posts: 353
posted June 24, 2002 10:22 AM
Check float levels and fuel pressure settings.

With alky and i will assume a belt drive pump you only need about 7-8 psi max pressure.

autoshop
Dirt Maniac

Total posts: 102
posted June 25, 2002 11:42 AM
You proabaly went to fat on the jet. Why would you go to a bigger jet for a smaller motor? Try dropping the fronts down a step or two or leaning down the idle screws since your in the transistion curcuit of the carb.

chief4car
Dirt Full Roller

Total posts: 56
posted June 25, 2002 06:57 PM
Your to rich. Back the jetting off. We changed the heads on our 406 this year. Went from 492's to DART Iron Eagles. Talk about better flow. Asked the guys from Hendrens if we needed to re jet the carb. The said nope once a carb is jetted for a particular engine that is where it should stay, within a size or so

Jim Cleaver
Cleaver Racing Inc

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