carburator backfire questions?

[84foxbox]

no i have the stock tachometer in their that works. as good as a aftermarket one.. its a wierd deal.. still at work till i go try the plugs and wires again.

[hotrodredneck]

my car did the same thing a few weeks ago when i put a new carb and intake on it. i had a vac leak when i fixed the vac leak it still did it i took my distributor apart and my advance weights we hung and wouldnt move i took them off and polished the staff to where they moved free fixed my problem.

[84foxbox]

well I got the backfire fixed!!!!!!!!!. but now at a low RPM it runs like it has a miss then when i put my foot in it runs great.. thinking a different jet size will help it out.?

[84foxbox]

i got the backfire to stop. but i jetted it way way down from where it was and it is still burning brand new spark plugs within a minute. and it is runnin rough at low RPM's and then it runs good up top.? any sugestions

[amcamx]

If it has backfired since putting on the alternator, maybe it is bad, and causes voltage spikes.
Ford has different firing order than Chev, but two rear cyl still fire next to each other. If those wires are crossed, it will backfire.
Does it backfire if you open the throttle slow, or only if you wack it? Unhook the secondary to see if it helps.
If the primary idle screw is one and a half turns in, it can be past the idle transfer slots, and be lean. The fix is to open the secondary, so the primary is no more than a half turn in. The secondary idle screw may be under the carb.
If you have the late type Ultra HP Pro, there is an idle air screw under the air cleaner stud. If your carb has this, adjust it first, and then the primary, and secondary idle as needed.

[jwhit]

Prabably a valve not seating!

[john dick]

You should never remove the primary power valve and richen the jets. This works fine on the secondary side, but not on the primary side. It will run way too rich at idle. Have you put a vacuum guage on the car? When you said it runs ok when you richen it to the point it fouls the plugs and runs rough when you lean it down, it made me think of a vacuum leak.

that is wrong..you can totally remove the jets and it will idle just the same..jet have 0 to do with idle..just saying.and .backfire out the carb , i would check my valves..its easy and free

[ken goddard]

sounds like a bit to much carb if motor is pretty much stock

[84foxbox]

fixed thx mokan

[the turtle]

So what fixed it? Just curious. Thanks

[hoggieman racing]

Changed the curve in the distributor, the springs were to heavy not allowing the timing to advance quick enough, and the 4 corner idle went from 1 1/2 turns to 7/8th of a turn, then he added some jet. WALLA, I knew we could get it! Thanks everyone for the ideas and suggestions, Thanks MOKAN for the Forum!!!