Sometimes the smallest things get overlooked regarding gas engines. One thing that seems like a small detail but has a major effect on gas engine operation is the spark plug. Spark plugs operate in severe conditions and require regular maintenance to provide desired engine performance.
The voltage required to produce a spark in the electrode gap has a direct effect on the life of a spark plug. Some things that are a main factor that affect the voltage required are the:
The service life of a spark plug varies for different applications therefore proper maintenance will help extend plug life and reduce down time. As the gap increases on a plug the voltage required for spark increases dramatically. A worn plug can require more voltage then the ignition system can supply. A cleaned and re-gapped plug requires more voltage then a new plug.
Some other things to remember when performing spark plug maintenance are:
Inspect the plug for deposits. A light brown or a beige deposit indicates normal operation. Deposits that are gray or black may be caused by excessive oil, or a substance that is introduced through the fuel system, or incorrect air-fuel ratio.
Look for eroded electrodes. An eroded plug is a worn out plug.
Always install a new spark plug gasket when installing or reinstalling a spark plug.
Install the spark plug into the seal by hand. If the spark plug cannot be seated by hand, there is a problem with the threads.
Do not use a thread tap to clean spark plug threads in the head. A tap is designed to remove metal and eventually could result in thread failure.
Do not mix types of spark plugs in an engine.
Do not use anti-seize compound on spark plugs, most of the heat is transferred through the threads and seat area.
Do not over-tighten a spark plug. Over-tightening the spark plug can cause cracks or can yield the metal which loosens the shell.
Never reuse a spark plug that is cracked.
Good spark plug maintenance will result in a better running engine and help reduce down time.
Do you have any additional tips you've used successfully?
Do you have experience with unique applications that require different types of maintenance (not listed above) or more frequent maintenance as a result of the environment?