MG T-ABC

has any body come across needles stamped with ap

AP is the lean needle

ES is standard

EM is rich

If you go to mintylamb, you can compare three different SU needles at a time. In this case, you can see how close the three needles cited above, really are, station by station.

Tom Lange
MGT Repair

i have found ap needles in my carbs is it a bad thing

I tried lean needles in my TC for awhile and they did not run very well, went back to standard.

I had the same experience as Stephen with lean needles.

I imagine the AP needles might be useful for a more or less stock engine at altitude. In carbureted V8's I will lean the carb at around 4,000 ft elevation. A bit more lean at 6,000 ft. You notice the difference. Not familiar with altitude tuning the XPAG in practice, as my TC driving range is from sea level to around 3,000 ft elevation.

To be more specific they were problematic in warm weather in stop and go traffic situations. Surging and generally poor running and idle. The standard needles worked much better.