You may have heard of the term “grenade gears” when researching the Kohler K series engines. Even I have heard many people proclaim they throw the balance gears out when rebuilding their engine, and that they don’t do anything anyways. When asked why, people often site some anecdotal evidence of gear failure they heard through an internet forum. It seems to me that few small engine enthusiasts understand why balance gears exist, why they are important, and what causes premature failure. I hope this article can help you make an informed choice when rebuilding your engine.
Let’s say you attempt to start your tractor and your starter does not engage. No click of the solenoid, nothing happens at all. Before assuming your starter is bad, grab your DMM and set it to DC Volts. Remove the wire going to the small terminal of your starter solenoid and connect the red probe of your DMM to the wire. Now connect your black probe to a ground. Turn your tractor’s key. Your DMM reads no voltage. This tells you that power is not going from your battery to the solenoid. Next remove the wires from the back of your ignition switch that are connected to the “B” and “S” terminals on your switch. Set your DMM to Continuity and connect your probes to the “B” and “S” terminals of the switch. Turn your tractor’s key and if there is no “beep” you know your ignition switch has a short internally and should be replaced.
In order to turn a shaft with combustion, we need to convert not only chemical energy, but we need to convert a reciprocating motion into a rotational motion. The reciprocating motion is the engine’s piston moving up and down, and the rotational motion is the crankshaft turning. As you can imagine there is a lot of things moving all at once with drastic changes in direction and speed. This process generates a lot of unwanted vibration and movement as a by-product.
The ignition circuit consists of your battery, ignition switch, ignition coil, breaker points, condenser, and spark plug. When your ignition switch is turned in the “start” and “run” position, the “I” or ignition terminal is energized and power flows from the battery through the primary winding of the ignition coil through the points and back to the engine ground. The primary winding of the ignition coil are the two small terminals marked + (positive) and – (negative). A small gauge wire goes from the ignition switch and connects to the + positive terminal of the ignition coil. The breaker points and condenser are both connected to the – (negative) terminal of the ignition coil. Your spark plug cable is connected to the secondary terminal which is the large wire port in the top of the ignition coil. Your spark plug is then connected to the high tension spark plug cable and screwed into your engine’s combustion chamber.