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Discussion Starter · #1 ·
Where can you get new spark plug wires and caps? I don't care if the caps are used, but would like new wires.
 

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Snagged this from a prior post.





I may be able to explain, at least as I know it. The wires on all the CX & GL's I have dealt with are solid, copper cored wire. Not like the automotive wire that is a carbon core. Our bikes used a resistor in the plug cap to minimized radio interference. I have a thought also that would be interesting to check out. That is the resistor also helps fire the plug better. I know if you sometime hold the wire end 1/8" away from the end of a non firing plug, it will then fire. Does the resistance somehow allow the spark to build to a higher voltage? I don't know. Anyone with true knowledge on this want to respond?



So, if you want to replace your GL wires, just go to the auto store and ask for solid core plug wire. In fact, I did that just this morning. I was there for other items and remembered to ask if they carried solid core wire. He went to the back and came out with a 100' reel that they would cut. This was at Carquest. The CX's do not have the wire removable at the coil except for cutting the old and splicing a new wire in. I have never done this, but would think with the proper insulation and heat shrink, it could be done.

Blue Fox
 

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Discussion Starter · #3 ·
Thanks BS, Guess I am going to stop for some wire on my way to DaveF's this weekend. What about plug ends, anyone have a set laying around or are they available new?
 

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Our bikes used a resistor in the plug cap to minimized radio interference. I have a thought also that would be interesting to check out. That is the resistor also helps fire the plug better. I know if you sometime hold the wire end 1/8" away from the end of a non firing plug, it will then fire. Does the resistance somehow allow the spark to build to a higher voltage? I don't know. Anyone with true knowledge on this want to respond?


Nope, the resistor is just something extra asking for trouble. You'd see the same results with or without it.
 

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Nope, the resistor is just something extra asking for trouble. You'd see the same results with or without it.


Ditto and if you are running any modern NGK plugs with an,"R" in the code they have the resistors in anyway so no need to double up




As for Wemoto.I treated one of my CX to a new collector box this week.Ordered it Monday Afternoon from Wemoto,got it Tues 4.30pm




Takes a bit longer across the pond but so far no one over that side has had any problem I know of with Wemoto for quality and speed.



As per other posts it may be worth buying a few other things to make up a decent little package like Water pump oil seal,gear lever oil seal,Tach main seal etc.Cheap little things that may go on our bikes that have been neglected before we got them.
 

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Nope, the resistor is just something extra asking for trouble. You'd see the same results with or without it.


I grabbed the whole conversation. That's why it doesn't have my name at the bottom. Wasn't editing anything.



And yes I run irridiums with the R for resistor. Ignitech seems to like the thought of using them.
 

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Discussion Starter · #8 ·
I know about the resistors and have replaced mine with brass rod. Just wanted info on the caps. Bike Bandit has em for $30 ea. A bit high for a piece of placing IMHO. Nice idea Shep, but those have already been replaced on floodie. Might need some seals for the parts bike though.
 

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I have a Kawasaki EX-500 parts bike...(pre-Ninja, but later became the Ninja with a few mods...)

It uses the XB05F Nichiwa or whatever company plug cap just like the CX500.



I'm considering getting the EX-500 running and discovered that the plug cap was about 4 inches long on the long side and then noticed it was the same brand (I think) as the CX-500 uses.



I'm attaching a PDF file link of how to replace the spark plug wire by Jon Pardue. (It's in the CT90 files buried in an archive)

(path if you are a CT90 Yahoo member is: Files > 1-2-3's of the Electric Systems - Jon Pardue > CT90 Ignition and Spark > Replace Spark Plug Wire II.pdf )

Jon is an electrical expert and had created this how-to for the CT90 coils but it works for many different Tec coils used in Hondas. It has been used successfully by many C70 and S90 owners as well as CT90 and CT70 owners...



Jon Pardue's Spark Plug Wire II replacement PDF file

PM me if you can't access it and I can email you the file...



David
 

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I found this interesting read on plug cap resistors:

http://www.ultralightnews.ca/articles/resistorcapsandplugs.htm



This test indicates that a resistor in the HT circuit slows down the discharge of the coils, making the spark last longer. This effect could be useful in CDI-systems since these have a very powerful, but short-lived, spark. A longer lasting spark should in theory give better chance of ignition under marginal conditions, like in a cold start situation, and the CDI-system is powerful enough to compensate for the slightly reduced spark power. So, in theory, a resistor plug, and/or resitor cap, should be better for our bikes than non-resistor types.
 

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The main conclusion I draw from that page is that the resistors are an RFI(Radio Frequency Interference) reduction device.Also our engines are not,"Rotax" engines.



The stock/original spark plug caps for my 1980 CX500A motorcycles do not contain resistors.Most people are likely running old or original either CDI units or Transistor Ignition spark units I can see no benefit of adding more resistance to the circuit and the extra contact points in those types of resistor plug caps are just more areas to corrode/breakdown IMHO.

The recommended spark plugs for the UK models were Resistor type spark plugs so no need for resistor Plug caps.The recommended Spark plugs for US models were none resistor spark plugs hence the Resistor type Spark plug caps to aid in RFI reduction.



I'm happy just to run none resistor spark plug caps with Resistor type spark plugs like NGK Iridium DR8EIX.No need to double up.
 

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...Also our engines are not,"Rotax" engines....


The ignition circuit does not know what engine it fires, in fact he tested with the spark plug in open air, so the engine make & model is not relevant in this case. What is interesting is that testing indicates that a resistor in the HT circuit effectively "slows down" the spark.



I don't think it is wise to add more resistance to the HT circuit no, however running WITHOUT resistors at all could possibly have some negative effect, by making the spark more powerful but also "faster". Since (AC) CDI systems are known for having "fast" sparks already this could be a problem.
 

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If you insert a resistor in series with an electronic circuit it will not introduce any delay in the initiation of conduction but will extend the duration of the discharge at the cost of a lower voltage at the output of the circuit.



In other words with the resistor in the plug &/or cap it's going to fire at the same time, however the initial spark will be a little weaker and slightly longer in duration.



Of course dealing with the high voltages used in an ignition system the effect is going to be minimal unless the resistor is of a very high ohmmage.
 
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