Check for faulty or sticking choke, overly rich fuel mixture, ignition problems, leaking fuel injectors, or spark plug heat range is too cold. If a spark is present, the spark plug is working properly. Like many automotive components, spark plugs don't last forever. Dry and Wet Fouling Although there are many different cases, if the insulation resistance between the center electrode and the shell is over 10 ohms, the engine can be started normally. Discussion Starter • #1 • Jun 17, 2016. You may be able to see this arcing on a dark night with the engine running. In this article, we’re just going to discuss heat range. Is it possible with the gas we have now days to get color (light brown) on the spark plug. Because the spark plug is inside the engine and is the only easily removable part it can be used as an indicator to the state of tune and condition of the engine. How often should I replace my spark plugs? Appearance - Firing tip is damp with gasoline, usually the odor of fuel is present on the spark plug. A light tan/gray color tells you that the spark plug is operating at optimum temperature and that the engine is in good condition. In order to perform the check we should follow the following steps: Ride the scooter warm. You can't be serious. The top of a new spark plug is covered in white ceramic insulation. You think your gas quality has to do with the color of the spark. If none of this works, you should call your local small engines repair shop to have it … Contact us and we’ll send over an electrician who can diagnose and fix the problem ASAP. Lean spark plug color. As spark plugs grow older, they lose their sharp edges as material from the center and ground electrodes is slowly eroded away. You can see the light brown color begin to appear on the left side of the insulator in the image below. Look at the spark plug porcelin for the color and condition of it. This is why spark plug manufacturers Champion Aerospace and Unison Industries recommend that spark plugs be serviced every 100 hours. Red is a sign of iron particle s or rust in the fuel system. A yellowish color is typically caused by leaded gas. ... which can have a greenish color. thanks. Is this OK?? The first is obvious, to create the spark necessary to ignite the air/fuel mixture in the cylinder. These usually look WET and smell of gasoline. The coil voltage measures about 100 volts and should be 130 volts. Spark Plug Wires-- Make sure the spark plug wires are not shorting out. If you have electronic ignition, a hotter spark is produced that will jump through old spark plug wires. Pull the rope to spin the flywheel and watch for a spark on the original spark plug. I've never seen an orange spark usually, white or blue color. If the firing end of a spark plug is brown or light gray, the condition can be judged to be good and the spark plug is functioning optimally. New spark plugs should be able to fully burn all of the air and fuel mixture in the engine cylinder and little to no carbon buildup should continue to occur. A hot spark plug maintains a higher internal operating temperature to burn off oil and carbon deposits, and has no relationship to spark quality or intensity. Plug colors tell the mechanic how the engine is running and can be very important. When a vehicle engine is reluctant to start, it often means that the spark plugs need changing. A lean spark plug will have little to no color on the insulator tip. Place the original spark plug back in, and set the spark plug wire against the motor. Generally accepted normal condition for a used plug in a properly operating engine is a light ash or gray color on the ground electrode, center wire and end of the plug. Single Fire - Single Plug: .035 to .040 Single Fire - Dual Plug: .022 to .025 Dual Fire - Single Plug: .035 to .040 Dual Fire - Dual Plug: .035 to .040 - When wired so each coil fires a plug … A bright blue is your most desireable and is usually a sign of a healthy ignition system. In reality, a spark happens every time you plug an … The black spots (look like pepper sprinkled on the plug) indicate a little too much heat on the plug which causes detonation by having the heated plug fire off the mixture prior to the spark firing. Normal spark plug color. Use a Coil-on-Plug (COP) Probe Grey to Light Golden-Brown Color . The sparkplug also says if you need to change anything in the mechanics. Any resistance at all would mean the plug is bad. The voltage at the coils are low. The coil on that year should be able to make a bright blue spark at least a half of an inch long. A spark, big or small, could cause an electrical fire. The insulator is often tinted the color of charcoal. Check the spark plug and the ignition wire to be sure they are both properly functioning. Because of this, the tool provides an accurate measurement of whether there’s enough spark to jump the plug gap. A quality spark tester, on the other hand, requires tens of thousands of volts to fire. Being able to “read” a spark plug can be a valuable tuning aid. Air/fuel mixture is too rich, the carburetor settings are incorrect. i took out the spark plug and checked out the color of the spark because my bike is hard to start and i heard that blue spark is good and yellow is bad well mine is yellow and i think it is because i put low octain gas in the first time riding . Conversely, a cold spark plug has a shorter insulator nose and absorbs more combustion chamber heat. Spark plugs have 2 jobs. 46 Posts . Like right out of the box, I'm I lean or will it take awhile to get color on them . This condition is ideal, the spark plug and engine air/fuel mixture are operating properly. If you replace your spark plugs and they are black and wet again in little to no time it may not be your spark plugs that are the actual issue. Black is the color … I hear the spark should be a blue color. A plug that has racked up miles should have a brownish or grayish color on the insulator and electrodes, but some gas additives have been known to turn fresh insulators blue, pink or purple. Normal spark plug color should show a light tan on the insulator tip. The spark plug is vital to the engine running and any problems with it could cause a multitude of engine difficulties. By "reading" the color of the plug you can tell a lot of things about how the engine is running. Have someone crank the motor and hold it close to the block. Sometimes, a visible spark at the outlet is normal. Plus, using a spark tester is safer than grounding a plug. DH Spark Plug off rear cylinder with 500 miles with AC, FP fishtails and dealer flashes. Save Share. 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