Backfire through carb.


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By redline - 10 Years Ago

Y-Blockers: My 292 has devleloped an issue that I can't seem to resolve. This motor has always fired right-up and run well. I tuned it up over the winter by installing new spark plugs, points, condenser, rotor button. I timed it and adjusted the carb. It started it up in the garage and it seemed fine. However, when I finally drove it recently, it bogs-down when I step on the gas pedal, looses power and backfires through the carb. I should mention that I have replaced the original carb with a Ford 2100 several years ago.
So anyway, I have been back through everything I did 4X, even putting back all of the old parts to no avail. I can adjust the carb 'till it runs smooth as silk, set the timing on 8 BDTC, point gap .015" Autolite 45 plugs. I have verified the vacuum advance is working and I have checked for other vacuum leaks. It still won't drive.
I took the top off of the 2100 carb and removed all of the moving parts, cleaned it w/Gummout and blew-out all of the little holes...
I do notice that it seems to miss a bit when cold and then runs smoother when hot. It idles higher when hot as well. I've adjusted the carb both hot and cold and that doesn't seem to make it run any different.
Any other ideas you might have would be helpful. I can't seem to figure this relatively simple engine out...and it has never giver me this kind of headache before. Thank guys...Bob

By charliemccraney - 10 Years Ago
So then it will cruise fine but does not accelerate well?  Is the accelerator pump working?
By Hoosier Hurricane - 10 Years Ago
If the carb has a Viton inlet needle, it may have become softened by the alcohol laced gas and sticking in its seat.  Also  check the fuel delivery lines and pump carefully, also make sure some insect has not built a nest or web in the fuel tank vent.
By redline - 10 Years Ago
Yup, I put a new accelerator pump on it and tried a different set of idle adjustment needles from a parts carb I have.
By Meandean - 10 Years Ago
Not much to add here, but make sure the plug wires are correct.   Years ago my Dad bought a 64 Fairlane with a 260 SB for a song because it didn't run well, had no power, and backfired through the carburetor.  Turns out the spark plug wires were crossed.  Fixed that and it ran like a champ!
By redline - 10 Years Ago
I actually numbered the cap and wires the last time I put points in it. I have been assuming I numbered them correctly, but will re-check the plug wires one more time...this almost seems like that kind if issue. Thank you...Bob
By redline - 10 Years Ago
I re-checked the wiress...they are all attached to the correct cylinder. 
By speedpro56 - 10 Years Ago
Did you install a new condenser along with the points? Sometimes you can get a bad new one if there from china. And sometimes a coil and or a ballast resister can go bad and cause the problem you're describing.
By pegleg - 10 Years Ago
You might want to check for a vacuum leak. Hoses, intake gasket Blah blah.
By MoonShadow - 10 Years Ago
Is this a start up after storage? How about a stuck valve? Chuck
By 56_Fairlane - 10 Years Ago
MoonShadow (4/14/2014)
Is this a start up after storage? How about a stuck valve? Chuck


X2!