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Harley plugs in fuel injected 2001 Heritage

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Old Oct 5, 2008 | 04:04 PM
  #1  
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Default Harley plugs in fuel injected 2001 Heritage

Has anybody ever subbed a Autolite 4164 or an NGK DCPR7E for a stock 6R12 plug?

Just wondering ,, I was wanting to do a plug change today but came across informatio saying HD uses a special sensor plug?

Anybody know anything about this? Sounds interesting anyhow.
 
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Old Oct 6, 2008 | 05:29 AM
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I haven't used an Autolite or NGK, however I've had good service with Champion plugs in my 2006 RK Classic.

I have always used the HD 6R12 plugs and "upgraded" to some of the HD Premium Platinum plugs thinking they would run better and last a bit longer. They only lasted me 3,800 miles and the bike started missing and basically running like crap. I ran down to the nearby Indy shop and they had NGKs and Champions. The bike has been running great with Champions for 15,000 miles now.

I'm not sure about the "sensors", but my FI bike hasn't had any problems with these non-HD plugs.

Edmo
 
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Old Oct 6, 2008 | 05:49 AM
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Well heres what i found. Not sure how critical it is but evidently our bikes are mapped using a HD plug therefore they suggest keeping with the plug............. if I am understanding correctly.

__________________________________________________ _____________________

More commonly known as knock retard.

First ION knock detection is the direction most applications are going to use. The old PEZIO sensor relied on a vibration ( caused by some level of knock ) to register at the sensor, It is very hard to detect low levels of knock and separate the signal ( knock from detonation ) from normal engine vibrations, such as valve closings on a Harley engine. On most vehicle applications the knock sensor can sense true knock from noise, but may not READ every cylinder in a multi-cylinder engine at every cylinder at every RPM, But most system use a GLOBAL retard scheme where any knock will retard spark to all cylinders at the same amount. New systems are going to individual cylinder knock detection where only the cylinder producing knock is retarded and only until knock ( detonation stops) so in a V8 or V6 you might only have one or two cylinders with any amount of retard.

The advantage of the ION system is it is not dependent on a sensor location and it can be calibrated to detect each cylinder at all engine speeds and loads.


ION sensing knock detection does not use a Sensor that is externally mounted on the engine. The name ION sensing is derived from the fact that as detonation happens IONIZATION at the plug tip changes the resistance to fire the plug. The actual detection to this change in resistance is internal to the coil and the signal is sent back to the ECM. Software tables are then calibrated using model based software. The way it is calibrated is important to understand WHY some folks are having TROUBLE. A very sophisticated Combustion measurement system is placed on a development engine and actual cylinder pressures are recorded vs. crank angle degrees and coil operating ranges, as the engine is running at set speed and loads. By reading "NORMAL" outputs from the ignition module electronics to the ECM input and noting the change when detonation causes Peak cylinder pressures to rise, a model can be developed that as long as the signal from the ignition module is outputting the "expected NORMAL" signal back to the ECM no retard will occur. A change in resistance value and amount can be correlated to a given rise in pressure in the chamber during combustion.Detonation causes very large spikes in pressure even at very low levels of detonation, so the model can and does detect even before "audible detonation ( that that can be heard ) happens. It is a very good system and very reliable with one HUGE exception. Detection is Dependant on the values calibrated in the software that represent knock, and are based on a stock engine ( or a known modified engine such as the STAGE I,II etc.) with a GIVEN set of Production intent parts.ie , Spark plugs, wires, and even compression ratio can and does change the resistance at the coil. So once folks start changing wires, Plugs ( to non-factory specs) and modifying the engine cams, compression ratio etc,( and even expected A/F ratios, and therefore combustion temperature) the values derived form a production engine are no longer valid and may cause the software to "determine" that knock is present when it's not or fail to detect knock when it is.

Just as production vehicles such as cars and trucks use similar schemes for many functions but most folks don't change parts or "hop-up" current cars with fuel injection systems... As an aside most people really don't know that if you change the air cleaner system or duct work ,even with a MASS AIRFLOW sensor you change the output of the mass airflow sensor. Those sensors are calibrated to read correctly only with a known set of induction parts. There is some amount of adaptability in the fuel system but it is possible to get even a closed-loop system, to where the software cannot adapt enough for some changes that one might make. EXHAUST, intake etc.


So Harley knock detection is really not that different than other vehicle manufactures, it's US the users that may not understand the impact on a calibrated system when making major or even minor changes. The STAGE flashes are calibrated to work correctly ONLY with very specific parts. One open exhaust or air cleaner is not the same as another of a different brand.... THE LEARNING CURVE will be steep and there is a lot of mis-information floating around.
 
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Old Oct 6, 2008 | 11:37 AM
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For my own info, where did you find this? Thanks
 
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Old Oct 8, 2008 | 10:30 AM
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Cant remember where exactly i found it but I do believe it was a JP tech article. My kids were searching for xbox cheat codes and filled up my browser history! So i cant find it.

But I tried to search it up again and found this!
https://www.hdforums.com/forum/engine-mechanical-topics/8861-tc-ion-sensing-detection-explained.html
 
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Old Oct 8, 2008 | 04:55 PM
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Thanks It makes sense. I have a stock '09 Ultra that I put in a set of NGK's and I would get sporadic pinging at around 3k rpm with a mild roll on. If I did a WOT no pinging. After riding awhile and getting the bike up to its riding temp the pinging would lessen so it would be very seldom. After I switched back to Harley plugs the pinging stopped. That was on the same tank of gas and using premium
 
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Old Oct 8, 2008 | 08:30 PM
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I changed my original HD-6R12 to NGK Iridium DCPR7EIX at the 10,000 mile service on my 07 Street Glide. The bike has around 10,6?? now. I have not noticed any pinging or loss of fuel mileage or performance. The radio works just fine. The service manual has a note about the stock HD plug. It reads

The number 6R12 plug is supplied as original equipment and is the only plug that should be used. The resistor plug reduces radio interference created by the ignition system and will not adversely affect performance or fuel economy.
 

Last edited by HOGNUTZ; Oct 8, 2008 at 08:38 PM.
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Old Oct 8, 2008 | 10:07 PM
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I could be wrong, but I think with the SERT you can turn the ION system off.
 
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