The Honda XRM typically uses a spark plug with an NGK CR7HSA designation. The spark plug thread size is generally 14 mm with a pitch of 1.25 mm. The reach of the spark plug is usually around 19 mm. It's always best to consult the owner's manual for specific details or any updates regarding your particular model.
.035 gap. DPR8ea-9 spark plug
You need an 18 mm spark plug socket.
Ngk - dr8es-l
most likely it will be a 5/8" spark plug socket.
18MM
Check the plug No. Last number is for the Gap size. NGK Resistor Spark Plug DPR7EA-9 The 9 is the gap size
The stock spark plug is the NGK DPR8Z gapped at 24 to 28.
5/8", available at Walmart $4.50 for a set of 3 spark plug sockets.
13/16" - at least that is the size for my honda 520S snow blower.
19mm thin wall.
The spark plug socket size for a Honda snow blower is typically 13/16 inch (21 mm). It's essential to use the correct size to avoid damaging the spark plug or the engine. Always consult the owner's manual for specific details regarding your particular model, as there may be variations.
Denso has published the following specifications for the spark plug suitable for the Honda TMX 155. Name of plug: Denso X24ES-U. This name is a code for certain specifications, for this plug they are the following: X means Hex size, in this case 12 x 18 mm. 24 is the heat range. E is the reach of the plug, in this case 19 mm without a gasket. S stands for a non-projected spark plug. U means a particular shape of the electrode, in this case a cut ground electrode.