How to Install an Hour Meter on a Sears Lawn Tractor. Installing an hour meter on a Sears lawn tractor will let you know how long the engine has run. This will help you schedule maintenance such as oil changes. The simplest meter to install is called a pulse sensor. It detects the ignition pulses that run through the spark plug wires to determine... Table of contents How to Install an Hour Meter on a Sears Lawn Tractor Things You'll Need 00:43 Tips & Warnings 02:58 -----------------