This area is prone to have some minor carbon build up no matter how well the plug is. Spark plugs are generally a brown or grey color, which is caused by normal ignition. 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. A lean spark plug will have little to no color on the insulator tip. As your plug heats up, a color line begins to form on the ground strap. But the plug will foul out after running it hard for an hour or two down at hard rock motorsports park in ocala. In general, a light tangray color tells you that the spark plug is operating at optimum temperature and that the engine is in. When installing a new plug, replace the old one with the same heat range. By examining the spark plug insulator color, an experienced personal watercraft engine tuner can determine valuable information. Sep 24, 2004 can too low of a spark plug gap cause my car to run too rich. How to diagnose and read the color of your spark plug. Spark plugs and what they say from engineering of cixi. If your spark plugs are fouled or damaged, it can lead to a host of problems. Oct 20, 2014 page 1 of 2 spark plug colour running lean.
By examining the insulator firing nose color, an experienced engine tuner can determine a great deal about the engines overall operating condition. Running proper timing also reduces exhaust valve temp which is another. After a test run, the spark plug can be examined with the naked eye or under a. My shop lowered the gap i dont know why and now its dumping fuel like crazy w and wo the chip. If the color of the strap changes near where it is weldedattached to the. Lean conditions are often caused by failures in the fuel monitoring system and should be addressed quickly. In our last article we discussed function, tip design, and heat ranges of spark plugs and. 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. 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. Try to use a toocold spark plug and you very likely will have to jet for a lean mixture to avoid plug fouling and as you lean an engines airfuel mixture down near the roughly14.
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. Race engine jetting excerpts from circle track magazine, april 2004, by henry olsen jetting a carburetor is one of the few black arts in the automotive world that is still a mystery to most racers and tuners, most tuners look at the spark plug, the exhaust port and the first 6 inches of the header for proper color and make a guess. Both the fuel mixture and the ignition timing result in coloring of the spark plugs porcelain and ground strap. It is important to recognize there is no industry standard for heat range. Look at the spark plug porcelin for the color and condition of it. Sometimes happens briefly during running in period. Excessive spark advance is even worse in its ability to produce detonation, and when combined. Fuel trims where to begin your diagnosis for rich or lean p0171, p0172, p0174, p0175 duration. You will usually see splotchy deposits on the plugs after the run, either green or yellow in. Cylinder 1s plug well was filled almost to the contact on the plug with oil. How to check your spark plug for the correct carburetor setting. When they say a tan color is ideal, that is in reference to a 4stroke engine or a. Jet more by feel more than plug color on a two stroke.
Plug reading discussion going on in our message board. Top end performance important technical articlejetting. That may not be the case with e85 due to variations in the mixture of gasoline dilution and variations in the blend of the gasoline dilution. 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. I replaced the plugs on my gti today and found something that ive not seen on previous cars. The actual color may depend on type of fuel you use. Run your gas tank down to a 14 or drain to there, and then put 5 gal of e85 in and run for about 10 miles to get it into the system. 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. Regardless of the problem, check for running rich or lean.
Automotive specialty tools colortune for 14mm spark plug. I recently just set the correct gap on my spark plugs, and now the bike is running rich. 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. For many racing engines, spark plug color is a window into the engine combustion process that can be used for tuning. My spark plug chart shows that this indicates an engine that is running too lean.
Lean conditions are hot engine, light color spark plugs should be a dry chocolate. Btw, the iridium spark plug will ensure better performance than standard spark plugs. Other than installing thermocoupler sensors in the combustion chambers the only real way that you know what is happening inside your engine is to read the spark plugs. A plug sits right inside the combustion chamber and can be removed for inspection. Spark plug fouling is a common cause of engine misfire.
Lean conditions can cause detonation of spark plug electrodes due to excessive heat, scorched and burned electrodes and melted areas of the spark plug. The insulator is often tinted the color of charcoal. If the color of the ground strap changes too close to the ground straps end, which is above the center electrode, then the heatrange is too cold, meaning that the strap is loosing heat too quickly to the base ring, and is not able to burn off deposits until. Metallic specks indicate lean jetting that is removing metal from the piston. Jul 24, 2018 fuel trims where to begin your diagnosis for rich or lean p0171, p0172, p0174, p0175 duration. Symptoms of running lean are overheating, bogging or loss of power, and delay of returning to idle from higher rpms. Bob is a retired welding engineer and author of 6 books about. Symptoms of running lean are overheating, bogging or loss of power, and delay. Now, ive got a ngk br9eix iridium spark plug, and looks like its running too lean wtf. Airfuel mixture is too rich, the carburetor settings are incorrect. When reading the plug, dont pay as much attention to the bit at the top of the threads. Im still really bad at telling what color my spark plug should look like, any thoughts on if this is a good color or if its to dark. Go through emissions with almost 0 co, and then go fill it up with regular gas and run it for at least 10 miles to get the e85 out of the carb and fuel lines, as it will eat the rubber seals.
How to read spark plugs to diagnose engine troubles. When a spark plug becomes fouled for any reason, the spark plug will fail to fire and ignite the airfuel mixture. 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. Racing spark plug cross reference for autolite, ngk and champion. For many racing engines, spark plug color is a window into the engine. Spark plug color remained virtually the same for all of the variations in air to the engine with a proportionate fuel adjustment. Your automobile keeps moving on the road because of the constant ignition. 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. Drag racing list spark plug reading 101 for gasoline motors. Heres what fouled spark plugs look like running too rich. Heres what fouled spark plugs look like running too. Here are the top 5 color variations and what information your spark plug is telling you about what is going on in your small engine.
A new set of plugs may take a few minutes to get some color on it. You need to check your spark plugs to see if you running rich or lean. This condition is ideal, the spark plug and engine airfuel mixture are operating properly. Exposure to heat and combustion byproducts changes the colors on the various parts of the spark plug. If engine temperature is excessive from the lean mixture, porcelain failure may occur.
Plug colors tell the mechanic how the engine is running and can be very important. This area is prone to have some minor carbon build up no matter how well the plug is running. Being able to read a spark plug can be a valuable tuning aid. The mechanic would install a new properly gapped plug. Jetting the airfuel mixture ratio shows up on the base ring the last thread ring, it has the strap welded to it. Caused by piston rings or cylinder walls that are badly worn. The image below shows a plug off a motorcycle that was running pig rich. Spark plug porcelain tan half way around and white the. You want a full turn of light soot color on the base ring if you want to tune for max. Check for faulty or sticking choke, overly rich fuel mixture, ignition problems, leaking fuel injectors, or spark plug heat range is too cold. The color should be read by looking at the porcelin insulator and compared to the plugs shown on the next few slides.
Spark plug reading can be complex and sometimes frustrating. Ignition system problems causing a weak or intermittent spark. Too little indicates lean jetting while excessive build. This causes a misfire, a loss of power and fuel economy, and an increase in tailpipe hydrocarbon hc emissions. Simply replace one spark plug with this tool hand tighten only, then start the motor and observe the color firing inside the cylinder. Plugs change colors and the different colors can explain such things as if the engine is running too hot or if the engine is worn.
Ive not replaced spark plugs on a gasser for quite a while, since my last car was a tdi, but i recall the tips generally. An examination, or reading of the characteristic markings on the firing end of the spark plug can indicate conditions within the. 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. Oct 17, 2011 spark plug color remained virtually the same for all of the variations in air to the engine with a proportionate fuel adjustment. As the spark plug can be removed for inspection, the effects of combustion on the plug can be examined.
This is usually caused by a carbon deposit in the cylinder head glowing hot enough to act as the spark plug. 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. Mine are not white, but definatly not black either. The reason im running at 18 fixed total timing is because i was getting a little bit of detonation in 5th gear in the 17002000 rpm range when the blower would go into 5 psi boost low rpm but high load, timing table was around 24 at that point, so i just set the entire timing table for 18.
The spark plug tip will bear witness to what is happening inside the engine. If it were running a tad bit leaner, the plug would have more of an tanash color to it. Heat range ground strap, the ground strap indicates the heatrange of the spark plug. Been chipped for approx 17k miles, had cai for 30k miles, tih for 5k miles. When an engine preignites, it fires before the spark is triggered for that cylinder. To read a spark plug, start by checking the color, since an undamaged spark plug will be light grey, or possibly tan. Even a couple of minutes can change a clean plug to sooty. 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. 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. I havent had a chance yet to pull one of the plugs to see exactly where.
This is the correct color a spark plug should be and it tells the mechanic everything is fine with the engine. Can too low of a spark plug gap cause my car to run too rich. Too hot a plug can mimic lean mixture, a cold plug can appear as a rich mixture. Without knowing your system inside and out, however, tuning with spark plug color alone can be misleading. Check plug temperature value, ignition timing, fuel octane rating might be too low and mixture setting too lean. If everything is good, the spark plug should have a tanlight brown color. How you can read spark plugs and select them by gordon jennings note. Oil may also be pulled into the chamber because of excessive clearance in the valve stem guides. Is it oil fouling, carbon fouling, ash deposits or overheating. Reading the spark plug jet more by feel more than plug color on a two stroke. Understand how to read the spark plug color car from japan. Was wondering if changing the spark plug gap could be the reason. A light tangray or brownish color, along with very little.
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. Jan, 2009 the actual color may depend on type of fuel you use. 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. As the rings seat in and power improves the fuel requirements will change. Blisters on the insulator tip, melted electrodes, or white deposits are signs of a burned spark plug that is running too hot. What color am i looking for on my plugs to know the motor is running at the right fuel mixture. By examining the spark plug insulator color, an experienced personal watercraft engine tuner can determine valuable information about the engines overall operating condition. 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 ground strap indicates the heat range of the spark plug. Orange too rich, lightbluewhite too lean, bunsen blue deep blue just right. How to read spark plug colors written by atlantic jet sports. I was wondering real quick if the spark plug gap will change the air fuel mixture.
Your engine runs lean if your airtofuel mixture is too light this means that. A spark plug initiates combustion in an internal combustion engine. 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. Automobile repairspark plugs wikibooks, open books for. Feb 23, 2018 your automobile keeps moving on the road because of the constant ignition. Bright white electrodes are an indication that an engine is running too lean. A clean, white insulator firing tip andor excessive electrode erosion indicates this spark plug condition. It left the shop with a new or hpipe and a iac as well. I have to put a new plug in after running a tank of gas through her.
If your engine is running too rich, the spark plug will be black and sooty. A tan colored plug means that the engine is running normal and the airfuel mixture is correct. Maybe im colorblind, but i cant tell if im running too lean, too rich, or just right. Spark plug heat range is too cold for the operating conditions.
I replaced the plugs a couple of hundred miles ago, and. Running lean also results in higher combustion chamber temperatures and preignition. Mar 23, 2015 im still really bad at telling what color my spark plug should look like, any thoughts on if this is a good color or if its to dark. 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. Spark plug porcelain tan half way around and white the other. So, you may well understand the importance of this device in keeping the engine running. Plug heat range can have a large effect on this process. After a long hard pull the over heated spark plug tip can fail or cause detonation. The heat range is a yardstick for selecting the correct spark plug.
Ideally you want the ceramic part of the plug a nice dark tan to medium brown color with a slightly darker ring right at the base of the threads of the plug. The white porcelain is showing a lean condition at wot, its not too far advanced as the. Tuning carburetors by ear is an art, but it is still not as accurate as the visual feedback provided by this tool. A common symptom of your car running lean is that your spark plugs are clean or turn white. 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.
However, your spark plugs will become either too clean evidenced by a lack of normal color or white when your engine is running significantly lean. Appearance firing tip is damp with gasoline, usually the odor of fuel is present on the spark plug. 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. If the color of the ground strap changes too close to the ground straps end, which is above the center electrode, then the heatrange is too cold, meaning that the strap is losing heat too quickly to the base ring, and is not able to burn off deposits until near its end. Rectify before piston rings break or valve faces burn.
Ive not replaced spark plugs on a gasser for quite a while, since my last car was a tdi, but i recall the tips generally being black. Kawasaki h2 750 is running lean motorcycle classics. Thus, a champion spark plug for your engine may have a different heat range than an acdelco or autolite meant for the same application. This will eliminate the spark plug as a heat source that causes detonation. Also, if the pcv valve is plugged or inoperative it can cause a buildup of crankcase pressure. Spark plug reading can be complex and sometimes frustrating task. The ignition timing can be checked by looking at the color of the plug.
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