If your engine is running too rich, the spark plug will be black and sooty. As the gap or pressure is increased the snapping blue spark will win. The electrode strap shows color all the way to the weld, indicating high combustion temperatures. If the engine is running to rich the spark plug will look black, sometimes a glossy black if its really rich. Check your owners manual to ensure that you have the correct spark plug for. Black sparks indicate that the temperature of the combustion chamber is too low. Check the owners service manual to determine the exact location of the spark plugs.
As the gap or pressure is increased the snapping blue spark will. When a spark plug becomes fouled for any reason, the spark plug will fail to fire and ignite the airfuel mixture. If it fires for a second or two the spark is fine and you know the carbs and possibly a fuel pump is not delivering gas. Spark plug color evidence of what is happening inside.
I recently just set the correct gap on my spark plugs, and now the bike is running rich. Dec 20, 2012 check out the images below, courtesy of ngk spark plugs, and get ready to do a little light reading the next time you pull your spark plugs. An examination, or reading of the characteristic colors and markings on the firing end of the spark plug can indicate conditions within the running engine. This condition indicates that spark plug temperatures have risen suddenly during a hard, fast acceleration period. A spark plug can become damaged for several reasons, most often because of an extremely lean condition or because the spark plug is too hot for the motor. The coil voltage measures about 100 volts and should be volts. Mar 29, 2019 to read a spark plug, start by checking the color, since an undamaged spark plug will be light grey, or possibly tan.
Your engine runs lean if your airtofuel mixture is too light this. So, you may well understand the importance of this device in keeping the engine running. Feb 16, 2011 dont beat yourself up trying to get a perfectly and evenly colored plug, just make sure that the color that it is is a good color. Spark plugs fact and fiction car craft magazine hot rod. The insulator is often tinted the color of charcoal. Heres a guide on how to detect issues by the color of deposits found on your spark plug. Spark plugs wear down over time, but how they wear can tell you a lot about your engine and how its performing. I noticed that the ground arm on the plug was kinda white. If the car has been running rich due to lots of idling or incorrect fuel mixture then it is possible to glaze the plugs and short them out during a run because of the sudden heating of the plug with the soot on the porcelain. Spark plug pictures for lean to rich running engines. Oil may also be pulled into the chamber because of excessive clearance in the valve stem guides. Replace spark plug s and crank engine slowly to distribute oil. A light tangray or brownish color, along with very little. Therefore, since the spark plug is the initiating factor in this mysterious combustion process it is imperative that we understand, 1.
A symptom of running rich is black smoke exiting from the exhaust. Spark plugs are generally a brown or grey color, which is caused by normal ignition. Oct 20, 2014 page 1 of 2 spark plug colour running lean. Reading the spark plug jet more by feel more than plug color on a two stroke. A healthy spark plug will have a little bit of electrode erosion but no abnormal deposits while the color would be a light tan, gray, or brownish. Prefix sign denotes new part numbers available 1196. Apr 16, 2017 check to make sure the plugs are tight but do not overtighten them. Running proper timing also reduces exhaust valve temp which is another. Im still getting the misfire code, plus now theres a clicking sound coming from the 246 side of the engine, and a p0174 code bank 2 running lean. Wornout spark plug preignition fuel additives ash deposits. Heres what fouled spark plugs look like running too rich.
Assuming no foreign particles have made their way into the motor, other causes include an undertightened spark plug or insufficient octane rating of the gasoline used. I just read the tuning link that you shared with us and i agree with most everything said except the color of the spark plug. Spark plugs can provide valuable information about your vehicles performance and can predict potential problems. Also, if the pcv valve is plugged or inoperative it can cause a buildup of crankcase pressure. A spark plug is an electrical device that fits into the cylinder head of some internal combustion engines and ignites compressed petrol by means of an electric spark.
Learning how to read a spark plug is quick and easy, and can equip you with the skills to determine when to change out your spark plugs for optimal performance in short, the reading of a spark plug involves evaluating the condition and color. Adjusting your carbs for performance in different throttle positions if you remember what throttle position each component of the carb control, you can begin to make some adjustments depending on the running conditions you experience. The ignition timing can be checked by looking at the color of the plug. This condition is ideal, the spark plug and engine airfuel mixture are operating properly. Use of various brands of synthetic oil will sometimes add extraneous colors to the ceramic portion of the spark plug, which can make things more interesting. All resistance values through the ignition system are per spec. Spark plug heat range is too cold and or caused by extensive lowspeed, short distance driving. However, your spark plugs will become either too clean evidenced by a lack of normal color or white when your engine is running. A good spark plug tester will pressurize its test cylinder to the same pressure as engine combustion chamber. Hold the light and its magnifier close to the plug.
Replace spark plugs and crank engine slowly to distribute oil. Spark plug how do i read my spark plug condition what. How to check your spark plug for the correct carburetor setting. In general, a light tangray color tells you that the spark plug is operating at optimum temperature. If the fuelair mixture is a deep blue colour, then the mixture is correct. If your spark plugs are fouled or damaged, it can lead to a host of problems including. Btw, the iridium spark plug will ensure better performance than standard spark plugs. What color should the spark be when using a spark tester. As a result, normal combustion deposits do not have an opportunity to fluffoff as they normally do.
A clean, white insulator firing tip andor excessive electrode erosion indicates this spark plug condition. Was wondering if changing the spark plug gap could be the reason. As the spark plug can be removed for inspection, the effects of combustion on the plug can be examined. Spark plug colours and engine problem guide download this sheet as a pdf file here a spark plug is an electrical device that fits into the cylinder head of some internal combustion engines and ignites compressed petrol by means of an electric spark. Ignition system problems causing a weak or intermittent spark.
Spark plug fouling is a common cause of engine misfire. It is right inside the combustion chamber and more importantly can be removed for inspection. Various color indications on a spark plug after one drag racing test run using 6percent nitro. If the engine is running to lean, the spark plug can look greyish white. You can use the burn color of your plugs and reference the plug color charts below to determine if your engine is running rich or lean. Airfuel mixture is too rich, the carburetor settings are incorrect. This causes a misfire, a loss of power and fuel economy, and an increase in tailpipe hydrocarbon hc emissions. Check for correct application of spark plug heat range too hot, wrong spark plug for engine, cross firing of ignition cables, over advanced timing, lean fuel mixture, defective egr valve, accumulation of combustion chamber deposits, hot spots in the combustion chamber due to poor heat dissipation, improper installation torque applied to spark. If your spark plug is white in color or appears blistered, that means something is making the plug run too hot. A motorcycle running lean will have little or no wear on the spark plug. How to diagnose and read the color of your spark plug. The image below shows a plug off a motorcycle that was running pig rich.
Jet more by feel more than plug color on a two stroke. Is your spark plug black, wet, greasy or dry, dusty or covered in soot, white and crusty or speckled with crystals, i will show you how to. Spark plug colours and engine problem guide download this sheet as a pdf file here. Lean airfuel mixtures cause plug tip and cylinder temperature to increase, resulting in preignition, detonation, and possibly serious spark plug and engine damage it is important to read spark plugs many times during the tuning process to achieve the optimum air fuel mixture. Lots of other things are more likely to cause preignition or knock. A melted electrode on your spark plugs means that theyve been running too hot for too long and could burn a hole through the top of a.
Lean airfuel mixtures cause plug tip and cylinder temperature to increase, resulting in. Tuning the engine with a colortune plug how a car works. Causes can include the engine overheating, incorrect spark plug heat range, a loose spark plug, incorrect ignition timing or too lean of an airfuel mixture. It is hard to see all the plug with the wrench handle in the way, but from what you can see they look ok. Replace with the correct heat range of autolite spark plug. For a given spark gap test an yellow spark against a blue spark. Brown or grayish tan deposit on side electrode, everythings fine. Check for problems in your engines cooling, a lean fuel mixture or incorrect ignition timing. Dec 11, 20 if you want to test if its spark or fuel just pull the spark plugs, replace them, but put a small squirt of fresh straight gas into the spark plug hole before installing the new plugs. Caused by piston rings or cylinder walls that are badly worn. Anything and everything you want to know about spark plugs.
Car seems to go pretty well, but i feel its a bit underpowered compared to my other mini which is a 1995 spi cooper currently half welded in my garage. The electrode wear is uniform and like the threads, should appear free of oil and unburned carbon. As the rings seat in and power improves the fuel requirements will change. Under a magnifying glass not necessarily visible to the naked eye, the porcelain shows a crack at the 6. A white or real light plug color could possibly mean the carbs is too lean. Again, look in your owners manual or online about how to clean your specific carburetor. Use a colder plug to lean it out, a hotter plug to richen it. Now i know this is a sign of the motor running lean. The white porcelain is showing a lean condition at wot, its not too far advanced as the total timing mark or color change is right in the apex of the ground strap curve.
Understand how to read the spark plug color car from japan. Plug heat range can have a large effect on this process. Spark plug pictures for lean to rich running engines this section provides a visual representation of how the spark plug can look depending on how the engine is running. Brown to grayishtan color and slight electrode wear. Spark plug porcelain tan half way around and white the other. Once you get the socket over the spark plug, place your hand over the head of the wrench, grasping the head firmly and pull the handle, hitting it gently with the palm of your hand to get it going. What a spark plug can you about your engines condition. How to check your spark plug for the correct carburetor. So took it for a desert run up to randsburg right next to red mountain here in southern cali. Appearance firing tip is damp with gasoline, usually the odor of fuel is present on the spark plug. Spark plug heat range is too cold for the operating conditions. Part number 276s may be used for header applications in place of pn 276.
When they say a tan color is ideal, that is in reference to a 4stroke engine or a. This plug eventually fouled and the bike would not start. How to read your spark plug motorized bicycle builder. Feb 23, 2018 your automobile keeps moving on the road because of the constant ignition. Check plug temperature value, ignition timing, fuel octane rating might be too low and mixture setting too lean. Spark plug reading can be complex and sometimes frustrating. Since improper heat range can easily cause detonation and spark plug insulator failure lets take a look at that. Replace with a colder heat range of autolite spark plug. Before inspecting plugs that have been run in your motor, familiarize yourself with a new spark plug first. A lean spark plug will have little to no color on the insulator tip. Spark plugs initiate combustion in internal combustion engines. It is hard to distinguish a plug with a too hot heat range from one running lean, but these are not hot plugs and they are not running lean. It means that the engine is running lean, which will result in the engine running too hot and can cause serious engine damage even seizure.
Hey guys, i was pulling a p0306 code misfire on cylinder 6, so i replaced my plugs, wires, distributor cap and rotor. With help from the spark plug experts at ngk, well teach you how to diagnose minor tuning issues or potentially major engine problems by examining your spark plugs. You lean it out some and run a few tanks through it but when you check again it is the same color. Correct heat range for engine and operating conditions.
How to assess trouble by checking your spark plugs dummies. 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. Your automobile keeps moving on the road because of the constant ignition. Symptoms of running lean are overheating, bogging or loss of power, and delay of returning to idle from higher rpms. With the engine running, you can then view whats going on in the combustion chamber. We recommend spark plug replacement at oe specified intervals or sooner if spark plug problems are suspected. Spark plugs are one of the most misunderstood components of an engine. The plug is showing me by the deposits on the tip of the electrode and also the deposits right on the edge of the threaded body.
Lets say you pull your plug and check color, you find it is a bit brown because you a little rich. Too little indicates lean jetting while excessive build. Jul 27, 2014 hi daniel, i had a shitty spark plug on my polini sport, equivalent with the ngk b9es, the color of the spark plug was chocolate brown. 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. Check for faulty or sticking choke, overly rich fuel mixture, ignition problems, leaking fuel injectors, or spark plug heat range is too cold. A common symptom of your car running lean is that your spark plugs are clean or turn white. Put new ngk plugs in last night and did an oil change, but the exhaust just wreaks of co which is the test i failed at idle. A light tangray or brownish color, along with very little electrode erosion, indicates optimal operation conditions, including a healthy engine and correct spark plug heat range. Two strokes make the best power at low engine temperatures and that combined with oil in the fuel and cold heat range spark plugs makes for a good plug reading that is.
I am starting the troubleshooting by looking at the ignition system. Too hot a plug can mimic lean mixture, a cold plug can appear as a rich mixture. Even a couple of minutes can change a clean plug to sooty. Now, ive got a ngk br9eix iridium spark plug, and looks like its running too lean wtf. Even though spark plugs are easily replaced, inexpensive and immediate ly improve engine.
How to read spark plugs to diagnose engine troubles. For the average stocker in good running condition, spark plug selection is a cinch choose whatever brand s on sale, look up the plug part number in. Home about us contact us technical corporate code of conduct pdf. Be aware that the use of 100ll will turn all these readings to a greyer color, but general appearance will still be similar. Check out the images below, courtesy of ngk spark plugs, and get ready to do a little light reading the next time you pull your spark plugs normal. The goal is to get a good dark coffee brown color on the spark plug, which represents the correct. Spark plugs have an insulated centre electrode which is connected by a heavily insulated wire. Sometimes happens briefly during running in period. I am checking my spark plugs to see how my engine is running. To read a spark plug and assess engine troubles, you first have to remove it. Checked the valves last night and they were very close to spec, the real issue is the thing failed smog, is running rich, i cant get it registered because of the smog issue and i dont know jack about setting a carb. Symptoms of running lean are overheating, bogging or loss of power, and delay. If you notice any black, dry soot on the spark plug, this is a sign of carbon fouling, which means your engine has been running too rich, and you should visit a mechanic to figure out the cause. An examination, or reading of the characteristic markings on the firing end of the spark plug can.
Reading spark plugs is a technique used by auto mechanics to diagnose conditions within an engine. Two strokes make the best power at low engine temperatures and that combined with oil in the fuel and cold heat range spark plugs makes for a good plug reading that is darker than most would expect to see. The spark plug tip will bear witness to what is happening inside the engine. Nov 03, 2017 how do you read a motorcycle spark plug.
Spark plug color is only accurate when checked after a high speed run, engine turned off at max rpm, and craft glided in with engine still off. If everything is good, the spark plug should have a tanlight brown color. They often come with specific instructions on how to remove the spark plug as well as. Over time, the spark plugs in a healthy engine develop a slight brown or tan tint of color on the center and ground electrodes. Rectify before piston rings break or valve faces burn. How to tell if a motorcycle is running lean and how to fix it. To read a spark plug, start by checking the color, since an undamaged spark plug will be light grey, or possibly tan. Blisters on the insulator tip, melted electrodes, or white deposits are signs of a burned spark plug that is running too hot.
The special spark plug is screwed into the spark plug hole in place of a normal plug. Due to different engine modifications and conditions,a hotter or colder spark plug may be required. Hi daniel, i had a shitty spark plug on my polini sport, equivalent with the ngk b9es, the color of the spark plug was chocolate brown. Notice the color of the porcelain insulator that is around the center electrode and also the color of the ground strap. When i get home and start tearing down my bike i decide the check my spark plug. Jul 24, 2018 how to diagnose and read the color of your spark plug video duration.
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