Hello and thanks, We are using long reach plugs, carbs were just rebuilt, dizzy plate, points, cond, red rotor all new, lucas sports coil[tested on multi meter and ok], spark from coil is white/blue, as well as at plug wire tips, dizzy has ground wire, no tracking in cap, pump psi is 1.5 to 2. Timing is advanced to 6 degrees. We have black smoke and black plugs. Plugs foul within minutes after start without choke and idled a 2000 rpm. Using 91 octane, ethanol free gas. Car has done this for 10 years. My buddy and I went through the carbs and dizzy, and had all problems rectified, which no "MG expert" has done in 10 years. So he enlisted my help and we had all problems corrected and problem persists. Engine was rebuilt several years ago and problem remained. Compression is 128, hot, all 4 cyl. Does not burn oil. Thanks....PS. My spelling improved a bit, with my glasses on!