Spark plug wire resistence

keikat2

90+ Posts
Jun 9, 2018
95
50
Forney, Texas, USA
I am thinking about changing the spark plug wires and spark plugs in my 2014 Tri Glide. I have owned this Trike for five years now; and, to my knowledge, the wires and plugs have never been changed. The 2014 Harley Touring Manual indicates the longer spark plug wire (34.75 inches) should be 8,688 to 23,178 ohms resistance while the shorter wire (16.75 inches) should be 4,188 to 11,172 ohms resistance which when divided by their length indicates the wires should have a minimum resistance of 250 ohms and a maximum resistance of 667 ohms per inch or a minimum of 3,000 ohms and a maximum of 8,004 ohms resistance per foot.

One set of wires I have been reviewing have as much as seventy-five (75) times less resistance while another set has ten (10) times less ohm resistance than recommended in the 2014 Harley Touring Manual. In turn, my question is "Can problems (IE: error codes, radio interference, etc...) be encountered if there is not enough ohm resistance in the spark plug wires? From what I have been reading, the supposed benefit of these lower ohm resistance wires is a more aggressive spark resulting in improved fuel burning. Any response(s) or experiences regarding this question, would greatly be appreciated. Thank you, Allen S.
 
I am thinking about changing the spark plug wires and spark plugs in my 2014 Tri Glide. I have owned this Trike for five years now; and, to my knowledge, the wires and plugs have never been changed. The 2014 Harley Touring Manual indicates the longer spark plug wire (34.75 inches) should be 8,688 to 23,178 ohms resistance while the shorter wire (16.75 inches) should be 4,188 to 11,172 ohms resistance which when divided by their length indicates the wires should have a minimum resistance of 250 ohms and a maximum resistance of 667 ohms per inch or a minimum of 3,000 ohms and a maximum of 8,004 ohms resistance per foot.

One set of wires I have been reviewing have as much as seventy-five (75) times less resistance while another set has ten (10) times less ohm resistance than recommended in the 2014 Harley Touring Manual. In turn, my question is "Can problems (IE: error codes, radio interference, etc...) be encountered if there is not enough ohm resistance in the spark plug wires? From what I have been reading, the supposed benefit of these lower ohm resistance wires is a more aggressive spark resulting in improved fuel burning. Any response(s) or experiences regarding this question, would greatly be appreciated. Thank you, Allen S.

What Jack said.

It is very important on your 2014 to have the spec'd resistance, that is what is needed for the ION sensing to work properly and prevent pre-detonation. Pre-det can damage your engine.

Quite a few years ago we tested 50 NEW sets of HD SE wires, over half of them were out of spec, straight out of the box.

You can see great plug wires at this LINK that you can depend on helping your Trike run well.

Kevin
 
Hi Kevin, As mentioned at the beginning of this thread, per page 1-47 of the 2014 Harley Touring manual, the OEM longer spark plug wire (34.75 inches) should be a minimum of 8,688 ohms resistance and a maximum of 23,178 ohms resistance while the shorter wire (16.75 inches) should be a minimum of 4,188 ohms resistance to a maximum of 11,172 ohms resistance which when divided by their respective lengths indicates the avg. minimum resistance should be 250 ohms and a maximum avg. of 667 ohms resistance per inch or a minimum avg. of 3,000 ohms resistance and a maximum avg. of 8,004 ohms resistance per foot. I have been looking at the Taylor Pro Race 10.4mm spark plug wires to replace my Trike's OEM Harley wires; however, the Taylor Pro Race wires state they only have 350 ohms resistance per foot which is approx. nine times less than the 2014 Harley manual stated average per foot resistance. In turn, have I somehow misinterpreted the ohm resistance numbers stated in the 2014 Harley Touring manual when converting the average ohms resistance to inches and then to feet? This is the reason for me starting this thread because I was concerned about the substantial differences between the 2014 Harley Touring manual and the 10.4mm wires' ohm resistance per foot as stated by Taylor. Looking forward to your response. Thanks, Allen S.
 
Hi Kevin, As mentioned at the beginning of this thread, per page 1-47 of the 2014 Harley Touring manual, the OEM longer spark plug wire (34.75 inches) should be a minimum of 8,688 ohms resistance and a maximum of 23,178 ohms resistance while the shorter wire (16.75 inches) should be a minimum of 4,188 ohms resistance to a maximum of 11,172 ohms resistance which when divided by their respective lengths indicates the avg. minimum resistance should be 250 ohms and a maximum avg. of 667 ohms resistance per inch or a minimum avg. of 3,000 ohms resistance and a maximum avg. of 8,004 ohms resistance per foot. I have been looking at the Taylor Pro Race 10.4mm spark plug wires to replace my Trike's OEM Harley wires; however, the Taylor Pro Race wires state they only have 350 ohms resistance per foot which is approx. nine times less than the 2014 Harley manual stated average per foot resistance. In turn, have I somehow misinterpreted the ohm resistance numbers stated in the 2014 Harley Touring manual when converting the average ohms resistance to inches and then to feet? This is the reason for me starting this thread because I was concerned about the substantial differences between the 2014 Harley Touring manual and the 10.4mm wires' ohm resistance per foot as stated by Taylor. Looking forward to your response. Thanks, Allen S.

Hi Allen,

I do not have any of the numbers handy right now to address your question (sitting at a picnic table in Baddeck, Nova Scotia).

However, I can tell you that we did all our research prior to using these wires and putting them on our site. I also ran them on my 2014 TG for over 4 years with excellent results.

As you may know, I monitor engine functions with my Power Vision and the Ion Sensing worked well with these Wires.

Kevin
 
Spark plug wires

I can personally vouch for the dk customs 409" PRO RACE WIRES. Around 1500 miles ago i installed them on my 15 FW. The results were amazing. They are approximately 2.5 times thicker than stock, so they are a bit of a tight fit under the tank. I raised my tank and put shop rag around pieces of 2x4 to hold tank up from frame. There is a noticeable increase in power, no more engine pinging even on steep inclines in 95° plus weather. I bought the tie wraps at hd dealer, pack of two around $3.00. Wires and plugs well worth the time and money. My original plugs at 25 were a nice tan. As an added footnote i have dk's external breather kit on since 20,000 and that is a great addition to power, burning straight fuel without engine snot!
 
Kevin, thank you for your reply. I hope you are having a great time in Nova Scotia. Are you North enough to see the Northern Lights? This is one of my "bucket list" items. My Wife and I are talking about going to Northern Canada, maybe in November, with the purpose of viewing the Northern Lights.

Regarding the spark plug wires ohm resistance, I know how proactive you are when testing and documenting the brand name performance items you sell on your website. Since you sell the Taylor Pro Race 10.4mm spark plug wires and ran them on your previous 2014 Tri Glide for four years, that is good enough for me. The only two things I was concerned about was radio interference and the possibility of too much spark which I do not know is even possible using the OEM Harley spark plug. Basically, I guess using the low ohm resistance spark plug wires will guarantee the necessary optimum power will be delivered to the spark plug to achieve its best possible spark.

Best of luck and safety to Mary and You on your trip. Once again, thank you for your response. Allen S.
 
Kevin, thank you for your reply. I hope you are having a great time in Nova Scotia. Are you North enough to see the Northern Lights? This is one of my "bucket list" items. My Wife and I are talking about going to Northern Canada, maybe in November, with the purpose of viewing the Northern Lights.

Regarding the spark plug wires ohm resistance, I know how proactive you are when testing and documenting the brand name performance items you sell on your website. Since you sell the Taylor Pro Race 10.4mm spark plug wires and ran them on your previous 2014 Tri Glide for four years, that is good enough for me. The only two things I was concerned about was radio interference and the possibility of too much spark which I do not know is even possible using the OEM Harley spark plug. Basically, I guess using the low ohm resistance spark plug wires will guarantee the necessary optimum power will be delivered to the spark plug to achieve its best possible spark.

Best of luck and safety to Mary and You on your trip. Once again, thank you for your response. Allen S.

Thanks man. We are having a great time. Very different up here. No, we have not seen the Northern Lights...although we have done pretty far north.

I am going to revisit all the numbers regarding plug wires when I return...a bit perturbed with myself that I am not remembering them. :xzqxz:

Kevin
 
Spark plug wires & pace maker

Just as a side note, My Wife has a pacemaker and after it was implanted, she felt sick when ridding on our 2016 Triglide. I changed the spark plug wires to aftermarket plug wires ([FONT=&quot]Magnum Sterling Chromite II Spark Plug Wires[/FONT]) and that eliminated the sick when riding problem.
 

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