To read a spark plug, start by checking the color, since an undamaged spark plug will be light grey, or possibly tan. Start the motor and pin the throttle, running through all gears. Black, carboned spark plug page 3 buggies gone wild. Feb 28, 2007 now just because a wheel is oldschool and rare, doesnt mean its sought after by enthusiast. Jan, 2009 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. I checked the colour of the spark plugs and knew it was running a bit. Excessive spark advance is even worse in its ability to produce detonation, and when combined. This means that the spark must jump the 716 gap and the spark plug gap in the motor while running. Efi mustangs tend to run lean and have white plugs at idle and part throttle cruise to get the engine warm quicker, to reduce fuel usage. Where to begin your diagnosis for rich or lean p0171.
If you want to maximize your chances of building something. The image below shows a plug off a motorcycle that was running pig rich. By examining the spark plug insulator color, an experienced personal watercraft engine tuner can determine valuable information about the engines overall operating condition. When new spark plugs are installed, replace with plugs of the same heat range. You can then also increase engine rpm to verify spark at higher speeds. Spark plug porcelain tan half way around and white the other. Iterate from plan a to a plan that works by ash maurya. If your spark plug has started to look white in colour, this indicates that something is making the plug run too hot. A light tan or gray is the normal spark plug color, but its a red flag when you spot a different hue. How to assess trouble by checking your spark plugs dummies.
If its fuel injected, reading plugs is not an accurate way of determining whether or nor the engine is running lean unless you do a full throttle run, then immediately shut down the engine and check the plugs. If the engine is running too lean, the spark plug can look greyish white. To do a plug chop, make sure the air filter is clean, warm up the motor, shut it off and install new spark plugs. 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. For a twostroke engine, having a fresh spark plug is incredibly important. Spark plug reading can be complex and sometimes frustrating. Too hot a plug can mimic lean mixture, a cold plug can appear as a rich mixture.
Jul 24, 2018 the tuneup special diagnosing and repairing a lack of spark plug maintenance. A list of some of the most common symptoms of incorrectly gapped spark plugs is laid out below. Plug colors tell the mechanic how the engine is running and can be very important. Plugs are still the honest witnesses of whats going on in the combustion chamber, and as don ward, e3 spark plugs lead engineer, puts it. Reading spark plugs spark plug tech super street magazine. The spark plug plating discolorations after a run indicate the portion of the spark plug that experienced higher temperature somewhere on that run. Reading spark plugs by mike chilando alkydigger technical. 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. Ugly, striking, unusual, atypical, overpriced, whatever you want to call it, here are 20 of the. The trick is learning how to read your spark plugs.
Iterate from plan a to a plan that works lean series 9781449305178. Spark plug color evidence of what is happening inside. Is there an issue with oil control or ignition timing. Your automobile keeps moving on the road because of the constant ignition. 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. You did not state how long the plugs have been in use and what gap you are running. Spark plugs are one of the most misunderstood components of an engine. How to read spark plug colors written by atlantic jet sports. Spark plug readings are most effective when a strong baseline is developed. A white or real light plug color could possibly mean the carbs is too lean. In our last article we discussed function, tip design, and heat ranges of spark plugs and. Timing is set at 36 degrees locked out running a crank trigger, carb is a 4500 holley jetted 210 on all four corners. 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.
Brown to grayishtan color and slight electrode wear. Airfuel mixture is too rich, the carburetor settings are incorrect. Reading your spark plugs is a valuable tool for performance tuning as well as for identifying possible problems with the mechanical condition of your engine. Spark plug pictures for lean to rich running engines this section. Nice, greybrown deposits, lightly coated core nose. If the engine is running to lean, the spark plug can look greyish white. A spark plug is said to be hot if it is a better heat insulator, keeping more heat in the tip of the spark plug. What color should the spark be when using a spark tester. This condition is ideal, the spark plug and engine airfuel mixture are operating properly. Drag racing list spark plug reading 101 for gasoline motors. How to check your spark plug for the correct carburetor. 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. Spark plugs and what they say from engineering of cixi.
Feb 23, 2018 your automobile keeps moving on the road because of the constant ignition. If your vehicle has a little less spunk lately, it might be time to change your spark plugs. If it were running a tad bit leaner, the plug would have more of an tanash color to it. The lean series the lean startup the movement that is. 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. When reading the plug, dont pay as much attention to the bit at the top of the threads. And, too high compression, or insufficient engine cooling. The plugs on the left would be ok for a 4stroke, but in a 2stroke they are lean, hot, and dangerous. I agree with the above post, i too would like to see a more tan color on the ceramic insolator. 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.
The nitrous outlet spark plug readers will give you the ability to properly read the spark plug for air fuel, timing, plug temperature, and detonation. If spark plugs are not discolored after a run, then either the engine is too rich or way too lean. Aircraft tool supply 10x illuminated spark plug inspector. If the chamber is too hot, this is most likely a sign of a lean mixture andor too much timing. I believe the stock main jet was a 340 and the guy i bought the bike from had changed out the main jet to a 350.
How to diagnose and read the color of your spark plug. So i know that if the jetting is correct the plug should be a tan color, black rich and white lean, but i pulled the plug on my yz250f and seeing a black ring around the edges and some of electrode, but it looks white on the tip of the electrode. The correct location to read the plug depends on what throttle range is being checked. I use mine in line between the spark plug installed normally in the engine and the plug wire. 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. Judging by that color, you are running too lean for sure. A common symptom of your car running lean is that your spark plugs are clean or turn white. The goal is to get a good dark coffee brown color on the. A plug chop is one way to verify your main jet jetting. A clean, white insulator firing tip andor excessive electrode erosion indicates this spark plug condition. Too little indicates lean jetting while excessive build.
Make sure that you blow out the cavities that the plugs are, to remove as much foreign material as possible. 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. This glazing of the porcelain actually becomes a conductor and the spark will jump from the electrode to the porcelain resulting is a very weak small if any spark. Black sparks indicate that the temperature of the combustion chamber is too low. Symptoms of running lean are overheating, bogging or loss of power, and delay of returning to idle from higher rpms. This area is prone to have some minor carbon build up no matter how well the plug is running. Iterate from plan a to a plan that works lean oreilly 2 by ash maurya isbn. Too hot a spark plug, low octane fuel, lean airfuel mixture. Start with a fully warmed up engine at normal operating temperature. When we buy hotter ngks for race cars we go from a 7 to a 9, are they a difference. The recommended 716 gap has always worked for me on outboard motors. If the engine is running to rich the spark plug will look black, sometimes a glossy black if its really rich. 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.
To read a spark plug and assess engine troubles, you first have to remove it. Correct heat range for engine and operating conditions. Remove the spark plug and examine the insulator the porcelain color. You can actually read your spark plugs for valuable clues about how your engine is operating. Even a couple of minutes can change a clean plug to sooty. Ive been running with the through the hood ram air for a while and have noticed that ever since i have my spark plugs have come out redbrown in color. 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. This along with some starting fluid never fails to start. This guide was designed to assist the technician, hobbyist, or race mechanic in understanding, using, and troubleshooting spark plugs. Incorrectly gapped spark plugs can negatively impact engine performance. Numerous questions have surfaced over the years, leaving many people confused.
You also need to be sure that you have the bike running at speed 50 to 60mph chop the throttle, pull in the clutch and shut off the ignition. How to read spark plugs to diagnose engine troubles. I replaced the plugs a couple of hundred miles ago, and. 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. Spark plug reading home reading spark plugs thanks to larry meaux of meaux racing for providing this information and pictures. A quick inspection can not only tell you if its time for new spark plugs, but can speak volumes about your automobiles engine condition as well. Ive check the cylinders when i had the im off and found no further redbrown anywhere in the engine. 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. It does the job of igniting the air and fuel mixture in the cylinders by providing sparks. This is only valid if you shutoff the engine after the finish line then tow the car back to the pits where you remove the plugs for reading. 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.
This plug eventually fouled and the bike would not start. If the engine is running too rich the spark plug will look black, sometimes a glossy black if its really rich. Oct 20, 2014 page 1 of 2 spark plug colour running lean. By reading the color of the plug you can tell a lot of things about how the engine is running. The simplest patterns affect all plugs in the rack. The insulator is often tinted the color of charcoal. The lean series, curated by eric ries, is a collection of books written by the. Btw, the iridium spark plug will ensure better performance than standard spark plugs. Most spark plugs look similar, but they are far from being alike. The heat range numbering system used by spark plug manufacturers is not universal. Now, ive got a ngk br9eix iridium spark plug, and looks like its running too lean wtf. 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.
So, you may well understand the importance of this device in keeping the engine running. Black, carboned spark plug i dont know about cart plugs but i thought you were going to a hotter plug and you got a 4 instead of a 6 and you had a 5. 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. 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. What are the symptoms of incorrectly gapped spark plugs. The plugs on the right would probably indicate imminent failure for a 2stroke. Engine spark plugs are responsible for igniting an engines airfuel mixture, a process that creates engine power. Ignition system problems causing a weak or intermittent spark. You will usually see splotchy deposits on the plugs after the run, either green or yellow in color and of course the tell tale shiny glaze. Are you an entrepreneur about to create a new web application. I installed ngks, and my stock plugs were black on the threads and the porcelain was a little dirty.
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. Appearance firing tip is damp with gasoline, usually the odor of fuel is present on the spark plug. 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. A lean spark plug will have little to no color on the insulator tip.
Why on earth would you want a carb with just two settings idle and off idle vs an efi that has hundreds of available combinations to meet the need of the engine. You want a full turn of light soot color on the base ring if you want to tune for max. My experience has shown a strong blue spark with a noticeable. This leaves high molecular weight fractions of fuel that will not burn, but eventually deposit condenstate on the in. You need to check if there is any problem in the cooling of your engine, or there is any scope for lean fuel mixture or incorrect. Spark plugs are generally a brown or grey color, which is caused by normal ignition. How to check your spark plug for the correct carburetor setting. If your engine is running too lean, the spark plug will be white. This info mainly pertains to 2 strokes at this time but may be updated at a later date. A spark plug is said to be cold if it can conduct more heat out of the spark plug tip and lower the tips temperature. Spark plug manufacturers use various systems to denote the heat range of their spark plugs. Feb 16, 2011 spark plug porcelain tan half way around and white the other. And if you are running with the choke on, something is wrong.
Thanks to larry meaux of meaux racing for providing this information and pictures. Both the fuel mixture and the ignition timing result in coloring of the spark plugs porcelain and ground strap. Be aware that the use of 100ll will turn all these readings to a greyer color, but general appearance will still be similar. Plug heat range can have a large effect on this process.
Like the mechanical version of the magic 8ball, your spark plugs may have the answers for you. Spark plugs can only be correctly read if the car has been shut down immediately at the end of a run without driving it back to the pits. 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 read your spark plug and show you what is normal. Check for faulty or sticking choke, overly rich fuel mixture, ignition problems, leaking fuel injectors, or spark plug heat range is too cold. Look at the spark plug porcelin for the color and condition of it.
Get off the track and coast to a place you are safely out of the way and either read the plug there or change one or two with some you have in your pocket so you can read these uncontaminated plugs when back. If the spark plug is black and oily, they are oil fouled. Understand how to read the spark plug color car from japan. Reading spark plugs is a must when properly tuning a nitrous system. I am checking my spark plugs to see how my engine is running.
We live in an age of unparalleled opportunity for innovation. 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. Finally, poor engine performance and a loss in fuel economy are traits of a worn spark. If your motorcycle does not seem to be running right, take a look at the spark plugs. Spark plugs are of great importance to all small engines, especially those used in idlestartstop applications like golf cars.
For example, a 10 heat range in ngk is not the same as a 10 heat range in champion nor the same in autolite. Exposure to heat and combustion byproducts changes the colors on the various parts of the spark plug. If your plugs indicate that something is seriously wrong with your engine, ask a professional for an opinion. Spark plug heat range is too cold for the operating conditions. This is my 3rd set of spark plugs ngk, bosch and densos. Now that you have taken an accurate plug reading and corrected any unusual patterns, its now time to analyze and solve the indicated problems.
Heres what fouled spark plugs look like running too rich. Long time no post but i could use some help reading this plug the motor is a 552 141 compression running alcohol. Iterate from plan a to a plan that works lean series. Buy aircraft tool supply 10x illuminated spark plug inspector. Whenever you are rejetting or tuning your carburetors, a plug chop can take away a lot of the guess work. With a carb it was very easy to be running rich or lean so you had to look at the plugs. Is it still important to read spark plugs and whats the. 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. Airfuel mixture is too rich, the carburetor settings are incorrect, or the flame arrestor is dirty or has mounting problems.
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