mgb misfire

[ROBRTM3 <ROBRTM3@aol.com>]

Dear List,

Have developed a problem.  Recently my 77 mgb has started to misfire or
"cough" at acceleration above 2500-3000 rpm in 3rd and 4th gear;  performance
improves  when backing off,  runs smooth at lower rpm and of course lower mph.
I am somewhat a novice and learning, but I have checked the plugs and they
seemed dirty with black dry soot deposits, cleaned them up a bit, but did not
have a real improvement.

Thanks in advance for your ideas and assistance.

Robert Murray
Katy, Texas