Polini Thor 250

Carburetor 28mm throat diameter, main jet 118 (according to Polini – could be something else, however). It is more like the Bing carburetors.

Spark plug – NGK BR10ES gap 0.9mm (0.035"). This is a resistor type spark plug. Pilots may also use the B10EG/ES or B9EG/ES. Use of a non-resistor plug may increase the amount of noise created by the ignition that is picked up by a two-way radio.