Re: OT!!! OT - WARNING OT! - Spark plug internal resistance -- OT OT OT ...with a later possible tie-in to Tek scopes!

Leon Robinson

Look at the ignition system in the dark with the engine running,
ANY BLUE GLOW is a problem area.

Leon Robinson    K5JLR

Political Correctness is a Political Disease.
Politicians and Diapers should be changed
often and for the same reasons.

On Sunday, July 7, 2019, 8:36:56 PM CDT, Mlynch001 <@mlynch001> wrote:

Plug wires should definitely have a measurable difference in resistance, proportional to the length, unless they are solid wire core, which has very little resistance.  What type of wires are you running?  I would do a compression test as a precaution.  Low compression will cause variation in firing voltages at the plugs.  NGK plugs typically use a 5K resistor for reduction of Electromagnetic Interference.  This was the typical " standard" value that we saw in my 25+ years in the motorcycle business for resistor plugs.  I would say that 20K was too much.  NGK or ND Resistor plugs were standard in later years, since HONDA insisted on using real copper ignition wires, not resistance wires and the interference from non- resistor plugs caused all kinds of issues with electronics.    Your spark energy will definitely vary from cylinder to cylinder, based on the plug resistance, wire resistance, compression and other factors.  When we ran a SUN tester, years ago, we allowed 5% +/- from low to high between individual cylinder spark peaks.  BTW, Interesting use of the scope!

Michael Lynch
Dardanelle, AR

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