Spark Plugs

Here is a video I did a few years ago for our customers. A bit dated, but the information still applies to today's engines.

This news video helps you understand how a spark plug is built, the difference between hot and cold plugs and a short list of practical and simple things you can do to help maintain good spark in your engine. 

I must emphasize these things are so important - use clean fuel; replace dirty air and oil filters; set up your motor with a properly matched propeller and drive gears for your boat and load; adjust your engine's throttle and governor; properly store your engine, and as importantly, annually check, clean and adjust the gap on your spark plugs.

Here are some additional helpful hints.

- If your engine is not running correctly; check your throttle adjustment; check for water in fuel and adjust your valves. Tip: Water is easy to spot in a fuel filter, but not so easy in the fuel tank. In a dark environment, shine a flashlight into the fuel tank opening and water droplets will appear like small diamonds in the bottom of your fuel tank. Use a heat fuel additive to dissipate the water. If excessive, remove the fuel and replace with clean fuel.

- Back to your spark plugs. When you remove your spark plug cap, do so gently with your hand anchored firmly against the engine. Rotate your hand while holding the cap. This prevents the cap from coming loose unexpectedly and causing damage to the wire and coil connection. Do not jerk the cap, or use pliers. 

- If you have poor engine performance when operating in the rain, or in salt water, check for spark loss.  If the spark plug cap is cracked or weather worn, it will leak spark. Sometimes, it may not be noticeable, however, you are loosing power.  In a dark garage or outdoors, spray water on the spark plug cap while someone throttles up your engine.  Add a little salt to the solution for better results.  If you see a fire show, replace the cap(s). 

- Fuel quality is very, very important. We recommend 91 or higher octane for all our performance engines. 87 or higher is fine for stock motors. Today's fuels concern us. We will talk more about this later.

- NGK makes a great after-market cap that is moisture resistant. You can get them at your local Napa. We will sell them here on the BPS site. (hint, follow installation instructions carefully and don't cut too much wire - Some spark plug wires when cut, will not reach the plug with aftermarket caps.)

Mud Doctor