83.5 1,9 wbx.
Good compression, New rotor, cap, plugs, wires, coil.  Checked spark
and it is strong. Fuel pump buzzes when it's supposed to. ( At
ignition on for a few seconds, then again when the engine is cranked.)

Starts well and runs strong until... Hot day like today, +30 C.

Then it starts easy runs strong until it heats up at which point it
does not like to come off idle.  If you play gently with the
accelerator it will catch and pull strong until you shift, when it
behaves like there is no fuel for a bit then catches and pulls.
Eventually it stalls at idle and will not restart until it has cooled
a bit.

  We pulled a plug and it appears light grey which I'm taking as a
sign it's running lean. Yes?

Could this be an AFM issue?

How do folks in the sunny south keep these things running??

Baffled by it all.....
don