What Cause an MGB to Bakfire?

["Mike Lewellen" <Mike.Lewellen@insightbb.com>]

I have continued to have problems with my MGB and backfiring.  It is
definitely better when it warms up but it still backfires quite a bit.  This
is a 76 MGB with a Weber 32/36 carb. It has a Holley 12804 fuel regulator, a
Lucas 25D distributor with a Pertronix ingnition from a previous owned.  I
have checked timing but not sure what it should be set at?

 

What cause an MGB to backfire?

 

Thanks,

 

Mike Lewellen

 

Lewellen@usa.net