Thread: Bang

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I have a chevy 400 that apon decelleration from above
5000 rpm it back fire and it sounds like a gun(BANG)!!~
I have messed wit my timing and found its sweet spot.
I have 750 demon and found its sweet spot.
The only other thing that i can think of is maybe a tite
valve. And since its out the exhaust i am think maybe a tite exhaust valve. But i also have a header pipe at the collector
flange a pipe is broken alll the way around i have heard that
exhaust leaks can create backfires. dont know if this is true
or not Any help is greaty appreciated




Bryon

friend's mustang does the same thing

Aww geez Denny!!! Can't I just do it till I need glasses???

Huh???? Who me??? Denny, go to the VW and Hot Rods site and check out my new ride!!! Quality unit like that will always get me home. Of all the things I've lost, I miss my mind the most.

Fix the header pipes, and don't do that from 5000 rpm's,
Your throttle is partially open, and on decel, the vac goes up, and draws fuel.
Denny are you trying to tell me that my header pipe is causing all this noise
iso if vac goes up and draws fuel i should'nt decel

vac is at about 12. So 1 day it isnt doing it the next day it is
and continues too

actually i put the stiff springs back in the advance and it did not seem to snap back quiet all the way but the weights where not making contact. the carb is a week old when i did try the advance after and be4 the change it was acting the same by hand
when released i could move it back some more by hand about .030. maybe my dist. is bad the main adjustment in the center of the carb is for idle purposes to keep the .020 of the idle mix slots at factory settings

ill check it out tomorrow thanks Denny

Denny 1 other thing if this dist. is bad can it be rebuilded
or is time for a new 1

thanks Denny!I fixed header pipe that backfire went away
also #8 plug was soaked prolly fouled replace that too
Now i know what the problem was i'll just get new headers