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techtalk:ref:genmsr02 [2019/09/19 02:42]
hippysmack [Reading Spark Plugs]
techtalk:ref:genmsr02 [2024/01/15 18:59] (current)
hippysmack
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 As such, there are several different methods to the same end listed. \\ As such, there are several different methods to the same end listed. \\
  
-As you read up on the various methods, you will find that some are geared to drag racing and are only concerned with idle and WOT. ((wedge of the XLFORUM ​http://​xlforum.net/​forums/showthread.php?​t=1110630&​page=3)) \\+As you read up on the various methods, you will find that some are geared to drag racing and are only concerned with idle and WOT. ((wedge of the XLFORUM ​https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​115789-am-i-reading-the-plugs-right/​page3?​t=1110630&​page=3)) \\
 After filtering through all the methods, consider the riding style of the bike you're tuning. \\ After filtering through all the methods, consider the riding style of the bike you're tuning. \\
 As a daily driver, tuning geared to circle track or road racing for your primary method may be best if you want your bike to work through all RPM ranges. \\ As a daily driver, tuning geared to circle track or road racing for your primary method may be best if you want your bike to work through all RPM ranges. \\
 And circle track methods do not skimp on reading WOT. \\ And circle track methods do not skimp on reading WOT. \\
  
-It takes some time and experience before you will be confident reading spark plugs. ((wedge of the XLFORUM ​http://​xlforum.net/​forums/showthread.php?​t=1110630&​page=4)) \\+It takes some time and experience before you will be confident reading spark plugs. ((wedge of the XLFORUM ​https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​115789-am-i-reading-the-plugs-right/​page4?​t=1110630&​page=4)) \\
 But once you master any plug reading method, it is a window into the engine that is invaluable in tuning. \\ But once you master any plug reading method, it is a window into the engine that is invaluable in tuning. \\
  
 Note that for a Sportster, it is quite normal for the front plug to look lighter/​leaner than the rear. \\ Note that for a Sportster, it is quite normal for the front plug to look lighter/​leaner than the rear. \\
 When tuning, aim for the tuning that gives as close to the ideal base ring color / coverage possible for both plugs. \\ When tuning, aim for the tuning that gives as close to the ideal base ring color / coverage possible for both plugs. \\
-The difference is due to variations in the air cooling, turbulence in the manifold and differences in exhaust lengths. ((FoxsterUK of the XLFORUM ​http://​xlforum.net/​forums/showthread.php?t=461641)) \\+The difference is due to variations in the air cooling, turbulence in the manifold and differences in exhaust lengths. ((FoxsterUK of the XLFORUM ​https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-era-specific-and-model-specific/​ironhead-sportster-motorcycle-talk-1957-1985/​69023-spark-plug-condition?t=461641)) \\
  
-The plugs are read the same way regardless of which throttle position / fuel circuit provided the reading. ((XLXR of the XLFORUM ​http://​xlforum.net/​forums/showthread.php?​t=1110630&​page=4)) \\+====== Quick Check Visuals ====== 
 +Examine plugs as soon as they have been removed. \\  
 +Deposits on the plug base are an indication of the plug efficiency and are a guide to the general condition of rings, valves carburetor and ignition system. ((1986 HD Dealer FSM pg 7-13)) \\  
 + 
 +  * A wet black or a shiny deposit on the plug base, electrode or ceramic insulator tip indicates an oil fouled plug. \\ May be caused by worn rings, pistons or valves. 
 +  * Dry fluffy or sooty black deposits indicate a too rich air/fuel mix or too long periods of idling. 
 +  * A light brown glassy deposit indicates an overheated plug. \\ May be accompanied by a cracked insulator or erosion of the electrode. Caused by a too lean air/fuel mix, a hot running engine, valves not seating or improper ignition timing. \\ The glassy deposit is a conductor when hot and may cause high speed mis-firing. 
 +  * White, yellow or light tan to rusty brown powdery deposits indicates balanced combustion. \\ The deposits may be cleaned off at regular intervals. ​       
 + 
 +====== Before Reading Them ====== 
 + 
 +Plugs can be read with as little as two laps on them at the track. ((wedge of the XLFORUM https://​www.xlforum.net/​forum/​sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​104264-plug-reading-101?​t=920271)) \\ 
 +You probably need to get several hundred miles on a set of plugs before you can use them for jetting purposes. ((XLXR of the XLFORUM https://​www.xlforum.net/​forum/​sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​73013-carb-basics-and-jetting-by-reading-the-plugs?​t=506958)) \\ 
 +Plug reading can get very complex and detailed. \\ 
 + 
 +The plugs are read the same way regardless of which throttle position / fuel circuit provided the reading. ((XLXR of the XLFORUM ​https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​115789-am-i-reading-the-plugs-right/​page4?​t=1110630&​page=4)) \\
 Any carb must be jetted properly at full throttle. \\ Any carb must be jetted properly at full throttle. \\
 But the secret to getting a carb Sporty to run well is getting all 3 throttle positions / fuel circuits correct. \\ But the secret to getting a carb Sporty to run well is getting all 3 throttle positions / fuel circuits correct. \\
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   * Overall readings can still be taken without a clean kill and stop, even without new plugs. \\ This is still very accurate, and one of the best tune up tools you have. \\ Just make sure that you have good plugs and by keeping an eye on them as you make changes you can read the effect that the changes made. \\ This just requires a mental track record or a written one.   * Overall readings can still be taken without a clean kill and stop, even without new plugs. \\ This is still very accurate, and one of the best tune up tools you have. \\ Just make sure that you have good plugs and by keeping an eye on them as you make changes you can read the effect that the changes made. \\ This just requires a mental track record or a written one.
  
-====== ​Before Reading Them ======+====== ​The Plug Chop Method ​====== 
 +You will get only a vague idea of the state of your AFR by just pulling your plugs and reading them. ((FoxsterUK of the XLFORUM https://​www.xlforum.net/​forum/​sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​73068-how-to-read-plugs?​t=507816)) \\ 
 +This is because the color of them will likely have been set in the last part of your last ride as you rode through town and pulled up at your garage before shutting off. \\ 
 +If you are tuning your carb then you need a slightly more rigorous approach. \\ 
 +The chop method is simple to do and gives good results: \\ 
 +  - Mark up your throttle grip with a turn of masking tape around the grip next to the switch housing. \\ Also put a piece on the switch housing with a single line. \\ On the grip's tape mark a zero throttle mark opposite the one on the switch housing. \\ Now open the throttle fully and mark this on the grip tape. \\ There will be about 1" around the grip between the two marks, mark up 1/8, 1/4 and 1/2 throttle too. 
 +  - Have a spark plug wrench handy in your pocket or tool roll. Also have a scrap of paper and a pencil.  
 +  - Find a long, straight, lightly-used section of road where its easy to ride at high speed but you can safely pull over and stop. \\ Finding this road is the hardest bit to the chop method. 
 +  - With the engine up to temp (this is very important), ride at a steady 1/8 throttle for 1/2 mile or so, the further the better. \\ With the throttle still open hit the kill switch, pull in the clutch and stop. 
 +  - Pull the plugs, read the color and write this down, don't rely on your memory. 
 +  - Repeat the above for 1/4, 1/2 and wide open throttle (WOT).
  
-Plugs can be read with as little as two laps on them at the track. ((wedge of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=920271)) \\ +You now have pretty good idea of the state of your plugs at the important throttle openings. \\
-You probably need to get several hundred miles on set of plugs before you can use them for jetting purposes. ((XLXR of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=506958)) \\ +
-Plug reading can get very complex and detailed. \\+
  
-Be careful about using pictures of plugs that may from the days of points and oil burning engines. ((XLXR of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=506958)) ​\\ +Please keep in mind that different types of gas will give different readings. \\ 
-Today’s plugs look a lot cleaner because of clean burning ​gas formulas, electronic ignitions and more efficient engine designs. \\ +Also, that race or av gas is more prone to oxidization ​and storage deterioration,​ along with the fact that a multitude ​of types are used worldwide. \\
-One thing about taking pictures of plugs is the light and camera settings can make big differences in how the plugs look on screen. \\ +
-{{:​techtalk:​ref:​carb:​spark_plugs_by_xlxr.jpg?​direct&​300|}} ((photo by XLXR of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=506958)) ​\\ +
-====== Where to read them ======+
  
 +Racing applications:​ ((http://​www.keihincarbs.com/​tips/​gate.html)) \\
 +When jetting the main jet, try to remember to jet for the best power for a given track. \\
 +An example of this is endurance where you would want to run a main large enough to keep the engine cool. \\
 +This means that you may be on the rich side but the engine will fade less towards the end of the race. \\
 +Another situation could be a stadium sx track where you spend much more time on the low to mid circuits. \\
 +In this case you may be running a main jet that is much smaller than your usual "​outdoor"​ jetting along with a hotter/​extended electrode plug. \\
 +As you gain experience and knowledge, you will be able to use other methods to determine your jetting. \\
 +A good tuner can "​feel"​ most of the circuits by slowly revving a parked bike, or just by looking at the color of the unpainted pipe and silencer. \\
 +But in the mean time always remember to change only one calibration component at a time. \\
 +
 +The best trackside method to determine the size of the main jet is to fully load the engine on a long straightaway or hill. \\
 +At the end of the stretch chop the throttle and hit the kill button simultaneously. The plug is then pulled for a "​reading"​. \\
 +
 +====== Where to read them ======
 +{{ :​techtalk:​ref:​genmsr:​line_diagram_of_spark_plug_1_by_hippysmack.jpg?​direct&​300|drawing by Hippysmack}}
   * Heat range and timing:   * Heat range and timing:
     * The porcelain is used for reading plug heat range, and timing only.     * The porcelain is used for reading plug heat range, and timing only.
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 Engine problems such as oil consumption,​ etc. are read by going back to your manual. \\ Engine problems such as oil consumption,​ etc. are read by going back to your manual. \\
 We are only concerned with a good sound engine for fine tuning purposes. \\ We are only concerned with a good sound engine for fine tuning purposes. \\
 +
 +For reading WOT position, inspect the positive electrode and the last 1/4 of the ceramic insulator. ((http://​www.keihincarbs.com/​tips/​gate.html)) \\
 +Best power will usually result in a very light tan colored insulator tip and dark colored ring around the tip of the electrode. \\
 +The electrode itself should have fairly sharp edges. \\
 +Example: \\
 +If the ceramic insulator has a nice tan coloring but the electrode has a white ring around the tip (and plug is in correct heat range), then you can easily run a size larger main jet. \\
  
 ====== How to Read Them ====== ====== How to Read Them ======
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 ==== Using the porcelain ==== ==== Using the porcelain ====
  
-  * Timing that has too much advance will show as black flecks on the porcelain. ((wedge of the XLFORUM ​http://​xlforum.net/​forums/showthread.php?t=920271))+  * Timing that has too much advance will show as black flecks on the porcelain. ((wedge of the XLFORUM ​https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​104264-plug-reading-101?t=920271))
     * These are flecks of aluminum off the piston due to detonation.     * These are flecks of aluminum off the piston due to detonation.
     * Even a good running engine will show signs of minor detonation, but keep an eye on those flecks.     * Even a good running engine will show signs of minor detonation, but keep an eye on those flecks.
     * If they get bigger and more of them, it’s time to look seriously at the timing.     * If they get bigger and more of them, it’s time to look seriously at the timing.
- 
  
 ==== Using the Ground Strap ==== ==== Using the Ground Strap ====
- 
 Ignition timing is directly responsible for the heat in the combustion chamber. ((https://​www.dragstuff.com/​techarticles/​reading-spark-plugs.html)) \\ Ignition timing is directly responsible for the heat in the combustion chamber. ((https://​www.dragstuff.com/​techarticles/​reading-spark-plugs.html)) \\
 (and therefore the color of the plug’s ground strap and the color of the first few threads on the outside of the plug). \\ (and therefore the color of the plug’s ground strap and the color of the first few threads on the outside of the plug). \\
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 First, adjust the basic timing to get both plugs to have the blue line just at the sharp bend in the strap. \\ First, adjust the basic timing to get both plugs to have the blue line just at the sharp bend in the strap. \\
 Then you can advance the ignition a little at a time to put the blue line just above the weld on the strap or whatever point gives you the best performance. \\ Then you can advance the ignition a little at a time to put the blue line just above the weld on the strap or whatever point gives you the best performance. \\
- 
  
 ===== Reading Air / Fuel Mixture ===== ===== Reading Air / Fuel Mixture =====
- +\\
 ==== Using the metal inner wall ==== ==== Using the metal inner wall ====
  
-  * The upper ring around the electrode area (as you hold the plug electrode up facing you) is where you read the idle mixture. ((wedge of the XLFORUM ​http://​xlforum.net/​forums/showthread.php?t=920271))+  * The upper ring around the electrode area (as you hold the plug electrode up facing you) is where you read the idle mixture. ((wedge of the XLFORUM ​https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​104264-plug-reading-101?t=920271))
   * Correct reading is MEDIUM GRAY. Light gray to whitish gray is lean, dark gray to black is rich (with powdery black being richer yet).   * Correct reading is MEDIUM GRAY. Light gray to whitish gray is lean, dark gray to black is rich (with powdery black being richer yet).
     * Then after that it starts to get wet and the black gets flushed off like it was rinsed with gas. \\ (You will see some of this on the intake valve side of the plug and that is not a concern if the color is correct otherwise).     * Then after that it starts to get wet and the black gets flushed off like it was rinsed with gas. \\ (You will see some of this on the intake valve side of the plug and that is not a concern if the color is correct otherwise).
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 ==== Using the plug base ring ==== ==== Using the plug base ring ====
- 
 The base ring of the plug is the ring with the ground strap welded to it. ((https://​www.dragstuff.com/​techarticles/​how-to-read-plugs.html)) \\ The base ring of the plug is the ring with the ground strap welded to it. ((https://​www.dragstuff.com/​techarticles/​how-to-read-plugs.html)) \\
 For a good AFR you want a light soot color on the entire circumference of the base ring. Ignore the porcelain/​insulator and ground strap to read the jetting. \\ For a good AFR you want a light soot color on the entire circumference of the base ring. Ignore the porcelain/​insulator and ground strap to read the jetting. \\
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 ===== Reading Plug Heat Range ===== ===== Reading Plug Heat Range =====
-  * Stock heat range of a plug should be good through stage 1 and possibly stage 2. ((wedge of the XLFORUM ​http://​xlforum.net/​forums/showthread.php?t=920271))+  * Stock heat range of a plug should be good through stage 1 and possibly stage 2. ((wedge of the XLFORUM ​https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​104264-plug-reading-101?t=920271))
   * If the compression gets raised too much, then you may need to drop to a colder plug.   * If the compression gets raised too much, then you may need to drop to a colder plug.
     * That will become evident if the porcelain gets dark tan to black and blistered.     * That will become evident if the porcelain gets dark tan to black and blistered.
  
-{{ :​techtalk:​ref:​genmsr:​spark_plug_ceramic_by_chrishajer.jpg?​direct&​300|photo by chrishajer of the XLFORUM ​http://​xlforum.net/​forums/showthread.php?t=31613}}+{{ :​techtalk:​ref:​genmsr:​spark_plug_ceramic_by_chrishajer.jpg?​direct&​300|photo by chrishajer of the XLFORUM ​https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​19034-reading-spark-plugs-to-determine-jetting?t=31613}}
    
 The porcelain around the plug’s center electrode can be divided into three areas for reading. ​ ((https://​www.dragstuff.com/​techarticles/​how-to-read-plugs.html)) \\ The porcelain around the plug’s center electrode can be divided into three areas for reading. ​ ((https://​www.dragstuff.com/​techarticles/​how-to-read-plugs.html)) \\
   * The area that is closest to the tip is affected by the idle and transition circuits carburetor circuits. \\ If this area is gray then you rode too far before shutting down and you cannot correctly read the plugs. ​   * The area that is closest to the tip is affected by the idle and transition circuits carburetor circuits. \\ If this area is gray then you rode too far before shutting down and you cannot correctly read the plugs. ​
   * The middle area is only colored when you ride down the road at around a steady 30-40 mph. \\ It is normally affected by the primary circuit jetting. \\   * The middle area is only colored when you ride down the road at around a steady 30-40 mph. \\ It is normally affected by the primary circuit jetting. \\
-  * The third area is all the way up inside the plug where the sun don't shine. \\ This area is colored when all is wide open under full power because the combustion chamber heat totally cleans off the other two areas. \\ It may take a special plug reading flashlight with the magnifying glass to view it correctly. \\ Plugs cannot be correctly read by just quickly looking at them with the naked eye. \\ You're looking at the fat end of the porcelain insulator, not at the tip. It's very difficult to see, and a light only makes it marginally easier. ((chrishajer of the XLFORUM ​http://​xlforum.net/​forums/showthread.php?t=31613)) \\ If you did not perform a plug chop, you're wasting your time looking for it in the first place. \\ The ring will be indicative of the jetting in all the circuits you rode in, not any one particular circuit.+  * The third area is all the way up inside the plug where the sun don't shine. \\ This area is colored when all is wide open under full power because the combustion chamber heat totally cleans off the other two areas. \\ It may take a special plug reading flashlight with the magnifying glass to view it correctly. \\ Plugs cannot be correctly read by just quickly looking at them with the naked eye. \\ You're looking at the fat end of the porcelain insulator, not at the tip. It's very difficult to see, and a light only makes it marginally easier. ((chrishajer of the XLFORUM ​https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​19034-reading-spark-plugs-to-determine-jetting?t=31613)) \\ If you did not perform a plug chop, you're wasting your time looking for it in the first place. \\ The ring will be indicative of the jetting in all the circuits you rode in, not any one particular circuit.
  
 Normally aspirated engines should have a light gray or tan hydrocarbon ring or as some call it a "fuel ring" all the way up inside around the third area. ((https://​www.dragstuff.com/​techarticles/​reading-spark-plugs.html)) \\ Normally aspirated engines should have a light gray or tan hydrocarbon ring or as some call it a "fuel ring" all the way up inside around the third area. ((https://​www.dragstuff.com/​techarticles/​reading-spark-plugs.html)) \\
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 These two different glazes will cause the plug to short out and misfire and raise ring lands or make a popping through the exhaust when going down the road. \\ These two different glazes will cause the plug to short out and misfire and raise ring lands or make a popping through the exhaust when going down the road. \\
  
-  * To determine heat range of your plugs look at the porcelain as it starts to take color. ((wedge of the XLFORUM ​http://​xlforum.net/​forums/showthread.php?t=920271))+  * To determine heat range of your plugs look at the porcelain as it starts to take color. ((wedge of the XLFORUM ​https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​104264-plug-reading-101?t=920271))
     * If the porcelain is white to a light tan, the heat range of the plug is right. ​     * If the porcelain is white to a light tan, the heat range of the plug is right. ​
     * Remember we are talking a couple of laps so it doesn’t have much time to take color which is why white is acceptable. ​     * Remember we are talking a couple of laps so it doesn’t have much time to take color which is why white is acceptable. ​
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 If you keep on adding timing until your finish MPH falls off but you still have no color on the plug’s ground strap but the porcelain has good color then your plug is too cold. ((https://​www.dragstuff.com/​techarticles/​reading-spark-plugs.html)) \\ If you keep on adding timing until your finish MPH falls off but you still have no color on the plug’s ground strap but the porcelain has good color then your plug is too cold. ((https://​www.dragstuff.com/​techarticles/​reading-spark-plugs.html)) \\
 If you have lots of color on the ground strap but the porcelain is clean and white then the plug heat range is too hot. The heat from the plug is cleaning of the fuel ring from the porcelain. \\ If you have lots of color on the ground strap but the porcelain is clean and white then the plug heat range is too hot. The heat from the plug is cleaning of the fuel ring from the porcelain. \\
- 
- 
- 
- 
-====== The Chop method ====== 
- 
-You will get only a vague idea of the state of your AFR by just pulling your plugs and reading them. ((FoxsterUK of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=507816)) \\ 
-This is because the color of them will likely have been set in the last part of your last ride as you rode through town and pulled up at your garage before shutting off. \\ 
-If you are tuning your carb then you need a slightly more rigorous approach. \\ 
-The chop method is simple to do and gives good results: \\ 
-  - Mark up your throttle grip with a turn of masking tape around the grip next to the switch housing. \\ Also put a piece on the switch housing with a single line. \\ On the grip's tape mark a zero throttle mark opposite the one on the switch housing. \\ Now open the throttle fully and mark this on the grip tape. \\ There will be about 1" around the grip between the two marks, mark up 1/8, 1/4 and 1/2 throttle too. 
-  - Have a spark plug wrench handy in your pocket or tool roll. Also have a scrap of paper and a pencil. ​ 
-  - Find a long, straight, lightly-used section of road where its easy to ride at high speed but you can safely pull over and stop. \\ Finding this road is the hardest bit to the chop method. 
-  - With the engine up to temp (this is very important), ride at a steady 1/8 throttle for 1/2 mile or so, the further the better. \\ With the throttle still open hit the kill switch, pull in the clutch and stop. 
-  - Pull the plugs, read the color and write this down, don't rely on your memory. 
-  - Repeat the above for 1/4, 1/2 and wide open throttle (WOT). 
- 
-You now have a pretty good idea of the state of your plugs at the important throttle openings. \\ 
  
 ====== Tuning ====== ====== Tuning ======
- +To bring this into perspective for the Sportster; ((wedge of the XLFORUM ​https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​104264-plug-reading-101?t=920271)) \\
-To bring this into perspective for the Sportster; ((wedge of the XLFORUM ​http://​xlforum.net/​forums/showthread.php?t=920271)) \\+
   * Stock timing will be acceptable unless it’s broken. Some over advance seems normal, just keep an eye on it over time looking for changes.   * Stock timing will be acceptable unless it’s broken. Some over advance seems normal, just keep an eye on it over time looking for changes.
   * Idle reading will be a function of the mixture screw, and the pilot jet.   * Idle reading will be a function of the mixture screw, and the pilot jet.
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 It's good to take a compression test and read the plugs every time you do a tune up and change the plugs every tune up to (5000 miles). \\ It's good to take a compression test and read the plugs every time you do a tune up and change the plugs every tune up to (5000 miles). \\
  
-You can't tell anything about the jetting by looking at the outside of the plug, especially when a plug chop was not done with a new set of plugs. ((chrishajer of the XLFORUM ​http://​xlforum.net/​forums/showthread.php?​t=31613&​highlight=plug+chop)) \\+You can't tell anything about the jetting by looking at the outside of the plug, especially when a plug chop was not done with a new set of plugs. ((chrishajer of the XLFORUM ​https://www.xlforum.net/​forum/sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​19034-reading-spark-plugs-to-determine-jetting?​t=31613&​highlight=plug+chop)) \\
 You can't just ride the bike around for a while (week, day, hour, whatever) and then pull the plugs and expect to be able to tell something about the jetting. \\ You can't just ride the bike around for a while (week, day, hour, whatever) and then pull the plugs and expect to be able to tell something about the jetting. \\
   * Newer HDs come jetted lean on the idle circuit and mid-range, and rich on the main.   * Newer HDs come jetted lean on the idle circuit and mid-range, and rich on the main.
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   * If your bike gets really exceptional gas mileage, you might be too lean   * If your bike gets really exceptional gas mileage, you might be too lean
  
 +====== Plug Pics ======
 +Be careful about using pictures of plugs that may from the days of points and oil burning engines. ((XLXR of the XLFORUM https://​www.xlforum.net/​forum/​sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​73013-carb-basics-and-jetting-by-reading-the-plugs?​t=506958)) \\
 +Today’s plugs look a lot cleaner because of clean burning gas formulas, electronic ignitions and more efficient engine designs. \\
 +One thing about taking pictures of plugs is the light and camera settings can make big differences in how the plugs look on screen. \\
 +{{:​techtalk:​ref:​carb:​spark_plugs_by_xlxr.jpg?​direct&​300|}} ((photo by XLXR of the XLFORUM https://​www.xlforum.net/​forum/​sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​73013-carb-basics-and-jetting-by-reading-the-plugs?​t=506958)) \\
  
- +|  Orange coloration from octane booster additive. ((photo by thesavageone33 of the XLFORUM https://​www.xlforum.net/​forum/​sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​169629-read-my-plugs?​t=1820463)) ((photo by thesavageone33 of the XLFORUM https://​www.xlforum.net/​forum/​sportster-motorcycle-forum/​sportster-motorcycle-intake-and-exhaust/​sportster-motorcycle-air-intake-carburetor-efi-fuel-and-exhaust/​169629-read-my-plugs/​page4?​t=1820463&​page=4)) ​ || 
 +|{{:​techtalk:​ref:​genmsr:​spark_plugs_1_by_thesavageone33.jpg?​direct&​300|}}|{{:​techtalk:​ref:​genmsr:​spark_plugs_2_by_thesavageone33.jpg?​direct&​300|}}|
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