Re: spark plug poll
HD 6R12.
Yes, the Champion RA8HC crosses over on any chart I've seen to the
HD 6R12.
Spark plugs
- Thread starter ryankesterholt
- Start date
Hoople
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Steve, I am confused. The 6R12 plug you say reads 16K ohms. Is that plug a GENUINE HD plug.?
By all rights that plug should read much higher IF it is a Genuine HD Plug.
And you say the Champ RA8HC with 75K is slightly used. I wish we had a Brand new one to see what is was.
By all rights that plug should read much higher IF it is a Genuine HD Plug.
And you say the Champ RA8HC with 75K is slightly used. I wish we had a Brand new one to see what is was.
Yes, the 6R12s that I tested are all Genuine HD plugs. If I get near the HD shop I'll pick of a couple new plugs and see what reading I get. I can also pick up a Champion. Might be a few days tho.
One thing I'm pretty certain of is that the Champion that everyone says is the same as the 6R12 reads differently.
R.Bingham
Active Member
After reading these posts I checked the Harley 6R12 plugs I just took out and only got 15.9 ohms on one and 16.2 on the other. Then I checked the new Champion RA8HC plugs that I had just put in last night. One read 26.2 ohms and the other 25.9 ohms. I also had another 6R12 plug laying around and checked it for grins and it only read 9.8 ohms. Go figure
The readings you got on the used 6R12 plugs are about the same I got. I'm going to try and get some new plugs today and check them out.
I'm curious mainly because of the resistance/ion sensing issue.
Hoople
Account Removed
And I will pull my used HD 6R12 Plugs out of my bike today. This way we will be cross-checking our work.
Yesterday I ordered a couple of sets of NGK DCPR7EIX plugs just to see what resistance
will be on those. Everything I read says they will cross over from HD 6R12.
I also e-mailed Delphi to ask about the requirements on the Ion Sensor. We have to get some answers on what's going on because this really is way too much drift in tolerance on these plugs.
Yesterday I ordered a couple of sets of NGK DCPR7EIX plugs just to see what resistance
will be on those. Everything I read says they will cross over from HD 6R12.
I also e-mailed Delphi to ask about the requirements on the Ion Sensor. We have to get some answers on what's going on because this really is way too much drift in tolerance on these plugs.
If I am understanding this right, if the sensor reads too much resistance, it retards the spark correct?
Would it be safer to use a lower resistance plug or a higher resistance if you do not have one in the proper range? All these varying readings are rather disheartening, no QC at all it would appear.
Would it be safer to use a lower resistance plug or a higher resistance if you do not have one in the proper range? All these varying readings are rather disheartening, no QC at all it would appear.
The ION system is designed to operate with certain values and changing anything such as the plug type or resistance would effect the operation of the system, and not in a desirable way. It's best left to operate the way it was designed and with the plug it was designed to work with.
Perfect. I have the NGK DCPR7EIX (iridium) in my bike now. Runs fine. I'll pull one and check it also.
Be very interested in what Delphi says.
Hoople
Account Removed
Very True Glider. But I won't rest until we all truly understand how it works.
At this moment all we really know is that it works and it needs to be left alone. But hopefully with the info we gather and Delphi's reply to my questions we may have the insight as to what is really going on. I am sure you will agree.
This much I can tell you.
1) The Ion Sensor electronics are built into the encapsulated coil. Use a different coil and you have no Ion detection Sensor.
2) The Ion sensor determines combustion PRESSURES by sensing back EMF from the secondary spark gap.
3) The Trigger information from the coil is sent to the ECM and the ECM compares it to a software value. The software value is FIXED and can not be changed using a SEST. Therefore my belief is that if you do anything to change the "normal combustion pressure", the EMF will change and the Ion sensor will not trigger at the correct threshold point.