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Old Aug 4, 2005 | 10:53 AM
  #1  
vansickle's Avatar
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Default carb popping

Hey Guys,
First post and i could use some help. My father has a 69 427 390hp. Has been sitting since last winter. When he first tried to start it up this summer had a loud popping noise and lots of smoke. Tried again last night, found the noise. Coming through the carburetor. Consistant popping. Ran fine last year until put away. Any ideas? Collapsed lifter?? Thanks in advance.
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Old Aug 4, 2005 | 01:13 PM
  #2  
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From: Burlington WI
Default Just a thought...

Try pulling one plug wire off at a time to narrow down which cylinder it is coming from.

Then run a compression test.

I may be wrong but it sounds, from what you described, like a valve isnt closing completely.

Or...

Pull the valve covers and watch the rockers and valves as you roll it over.
You might want to disconnect the coil wire or you will have oil all over.
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Old Aug 4, 2005 | 02:14 PM
  #3  
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From: St. Charles Mo
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Default

Originally Posted by fl_rider
Try pulling one plug wire off at a time to narrow down which cylinder it is coming from.

Then run a compression test.

I may be wrong but it sounds, from what you described, like a valve isnt closing completely.

Or...

Pull the valve covers and watch the rockers and valves as you roll it over.
You might want to disconnect the coil wire or you will have oil all over.

The BB 427's and 454's are notorius for broken valve springs. That would cause your symtom. Just rolling it over at low rpm might not show an obvious problem. Do a thourgh inspection of all valve springs, both the inner and outer..

If you are really unlucky, you could have a worn off cam lobe, but that should be real obvious
Good luck
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Old Aug 4, 2005 | 02:34 PM
  #4  
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vansickle
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Default

Thanks for the info fellas. At least we know where to start now.
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Old Aug 4, 2005 | 04:40 PM
  #5  
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From: 68 427 4.11s Roadster
Default

Check the innards of the cap. It might be cross firing due to moisture or carbon tracking.
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