Ok,,,,,,, I'm not REALLY wanting to beat this subject into the ground, but please allow me to summarize some of the additional information that has come to light regarding the sparkplug & sparkplug wire issue...
Craig E.,
You pointed out - be it good or bad - these Cubbies will run with different plugs than what the manufacturer calls for.
Regarding heat ranges, it is a common practice to use a sparkplug with a step higher or lower heat range, depending on individual engine condition and operating conditions. In tired engines that may be passing a bit of oil, it may perform better with a higher heat range or hotter plug to keep the oil burnt off. Whereas, the use of a lower heat range or colder plug due an increase in compression (possibly due to carbon buildup inside the combustion chamber) or elevated operating temperatures is sometimes advantageous.
Bruce N.,
Thank you for the excellent explanation on how different ignition systems call for various sparkplug gaps, how the gap grows with use and the importance of using the correct depth plug due to their 'extended nose or thread length' differences. Note: Thread depth and nose length comparison information is obtainable from the various sparkplug manufacturers/suppliers.
Richard C.,
You pointed out that when you use a solid core sparkplug wire AND a NON-resistor Autolite 216 sparkplug, it DOES INTERFERE with the operation of your electronic tach (causing needle bounce). However, when you use a carbon core wire (RFI-resistant) your tach doesn't experience needle bounce. You also indicated that you also run a "Point Saver" ignition system, I don't know if the "Point Saver" system is an electronic device or not thus be effected or not by the use of a solid core wire. Never-the-less that is very interesting information.
I wonder if you'd still have tach issues IF you were to install the solid core wire and a RESISTOR-TYPE PLUG (such as a Champion RH10C) instead of the NON-RESISTOR Autolite 216?
Richard C. & Kendall I.,
You both mentioned that you have run carbon core wires for MANY years without any performance problems -- I don't doubt that for a moment. However, not all things last the same for all people. In addition, I suggest that many of us will attest that these Cubbies will STILL RUN when in various states of tune.
It's been my experience with my Cubbie, the level of performance usually drops off over time, not abruptly; so I likely will not readily notice a small or gradual loss of performance. However, once I perform a tuneup or restore the points or sparkplug or even change out 2 month old fuel for fresh fuel, I believe I can really notice the difference in performance. This shouldn't be looked at as increase in performance - rather a 'restoration' of performance. Only if I start to 'hot rod' the components would I look for any improvement or increase in performance over stock.
Richard C. & Kendall I.,
I'd be REAL curious to know what the Ohm reading of your 'many years old' carbon core wires is? If your wires have a few hundred Ohms of resistance, your performance may benefit by the installation of a new wire.
Myron B.,
Thank you for reminding us that their are "differences in information" such as with the varying sparkplug charts.
Just for the record, when I went through my, 'Kohler Engines Owners Manual, Operating and Maintenance Instructions Manual' (which pertains to the K301 engine & what came in my 129), I could NOT locate any mention of inspection or replacing of the sparkplug wire in THAT manual.
In addition, in THAT manual on page 9, it did say to use a RESISTOR-TYPE sparkplug: "Every 100 hours of operation, remove the sparkplug, check its condition, and reset the gap, or replace with a new plug...if worn or reuse is questionable. Use a Champion type RH10 (or equivalent) spark plug."
Craig E.,
You indicated that you have all the combination of parts to do a side-by-side comparison. Please bring your findings back to this group....
Tedd I.,
I am also very interested in to hear how your Captain Kirk Bosch DUAL COIL upgrade goes.... I hope you also come back and share your findings with everyone here!
Ryan W