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.
.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.
.044" for most brands.
When changing the spark plugs of a car it is important to leave the right gap size. The Spark plug gap for this car is .042 inches.