Author Topic: The resistor cap plug wire combination mystery  (Read 7358 times)

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dudeman750

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The resistor cap plug wire combination mystery
« on: May 12, 2007, 01:30:57 PM »
So what gives here? I just read a bunch of posts about this topic. My manual for my 82 CB650SC says it takes DR8ES-L Plugs. This means resistor type right? So I should go to NAPA and get copper plug wire, and get 5k NGK caps? should I get D8ES plugs then or DR8ES?

Offline TwoTired

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Re: The resistor cap plug wire combination mystery
« Reply #1 on: May 12, 2007, 01:37:10 PM »
You either get resistor caps OR resistor plugs not both.  You can get caps without resistors, too.
« Last Edit: May 12, 2007, 01:49:44 PM by TwoTired »
Lloyd... (SOHC4 #11 Original Mail List)
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dudeman750

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Re: The resistor cap plug wire combination mystery
« Reply #2 on: May 12, 2007, 01:39:32 PM »
Thanks, get then... copper core wire, non resistive? and either non resitive caps or plugs then? but not both?

Offline TwoTired

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Re: The resistor cap plug wire combination mystery
« Reply #3 on: May 12, 2007, 01:53:46 PM »
I wouldn't expect the 650 to use resistor cored wires.  But, I can't be 100% on that.  Were the old ones solid core?
You don't have a High Energy ignition system.  Resistors at or near the spark plug would be my expectation.
Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

dudeman750

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Re: The resistor cap plug wire combination mystery
« Reply #4 on: May 12, 2007, 08:40:25 PM »
New developments. I pulled the coils off and found that I have dyna coils installed. Very wierd, the number 1 wire looks great where it attaches to the coil, but the #4 was so corroded the center conductor no longer was connected. The same thing on the other coil as well, the #2 was shiny but the #3 was again eaten away. I redid the connections to the coils, but Im not sure if I wired it right... shouldnt really matter should it? the 1 and 4 fire at the same time and the 2 and 3 as well right? Im off after this to look up the dyna coil wiring. seems to me that the 1 and 4 plug wires and input wires would be interchangeable? same with 2 and 3? well I slapped it back together and fired it up, but I could hear something arcing down there. Gonna get some new wires tomorrow, but im not sure how they are going to connect to the coil yet. These had some crimped on things on them, PO home made it looks like. The plug caps are non resistor, look like automotive ones.

Offline oldfart

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Re: The resistor cap plug wire combination mystery
« Reply #5 on: May 12, 2007, 10:50:41 PM »
No Honda motorcycle has resistor wires.  Some are stranded copper, some are stranded stainless steel.  All are considered permanent.  Despite some other manufacturer's use of them, resistive wire is bad news on a motorcycle. 

Resistor caps are another story.  They were a development on road bikes only for RFI issues.  On dirt bikes, they had some additonal benefits and reasons.  Resistor plugs were used on many road bikes starting in the late 70s, but by Honda's own admission, they appeared on Hondas only because it made economic sense to include U.S. models in what became in the 80s a Euro requirement, again RF-related.  Late model bikes with fuel injection and/or engine management systems are entirely another story.  They have higher resistive caps than earlier models, and of course resistive plugs as well, as do all Hondas from the early 80s onward.  The electronics on these machines are protected thereby. 

The purpose of both resistor caps and plugs is to dampen a byproduct of ignition coil action that produces radio waves, radio frequency interference actually, RFI, with the downside some slight reduction in ignition intensity, though not enough to matter on an otherwise well-kept machine.  Therefore, going non-resistor can in fact boost ignition potential, a complicated subject in itself, but not necessarily actual performance unless other factors are in place. 

For the whole picture, in logical order, try the link following. 

http://www.motorcycleproject.com/motorcycle/text/plugwiretech.html

Mike Nixon
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Offline Clutch Cargo

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Re: The resistor cap plug wire combination mystery
« Reply #6 on: May 13, 2007, 04:12:26 AM »
TwoTired,

Where can I get non-resistor caps for my 750K6?

Mike
1976  CB750K6
1976 GL1000
1994 - ST1100
1985 - HRS21

dudeman750

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Re: The resistor cap plug wire combination mystery
« Reply #7 on: May 13, 2007, 10:18:11 AM »
I went to NAPA and they looked at me confused. After some checking, I found you can order metal core wire. I went home, and took another look at my wires. I now determined that they are dyna wires and I have dyna 2.2 ohm coils. I still cant get the spark plugs 2 and 3 out though. Dont know where to get a wrench either,, my next hurdle. Anyway I electrical taped up my wires and guess what? problem solved, the bike now pulls hard to redline. Before I couldnt get over 5 to 7k RPM.

Offline number13

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Re: The resistor cap plug wire combination mystery
« Reply #8 on: May 13, 2007, 10:28:06 AM »
Quote
still cant get the spark plugs 2 and 3 out though. Dont know where to get a wrench eithe

Use the spark plug wrench in your tool kit, if
you still have it. It really is the best tool for that job.
Bikes parked out front mean good chicken-fried steak inside.

dudeman750

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Re: The resistor cap plug wire combination mystery
« Reply #9 on: May 13, 2007, 10:30:57 AM »
wish I had the tool kit... it was gone when I bought it.

Offline TwoTired

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Re: The resistor cap plug wire combination mystery
« Reply #10 on: May 13, 2007, 10:51:44 AM »
TwoTired,

Where can I get non-resistor caps for my 750K6?

Mike


A few years ago, I was on a first name basis with the Honda parts counter people.  I went in with a broken plug cap.  They looked up the number in an NGK catalog they had, then asked me what resistance I wanted, as there were 4 or 5 variants of the same plug cap with different resistances.  One of the options was zero, others, were 5K, 10K, and more I don't recall specifically.

So, if you can find a Honda parts counterman, or a general motorcycle repair shop willing to spend some time on you, they should be able to get the NGK numbers and the parts you seek from their catalogs.

Cheers,

Lloyd... (SOHC4 #11 Original Mail List)
72 500, 74 550, 75 550K, 75 550F, 76 550F, 77 550F X2, 78 550K, 77 750F X2, 78 750F, 79CX500, 85 700SC, GL1100

Those that learn from history are doomed to repeat it by those that don't learn from history.

Offline oldfart

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Re: The resistor cap plug wire combination mystery
« Reply #11 on: May 13, 2007, 01:36:34 PM »
Yes, those variant caps have been available for many many years.  The problem with the 0 resistance plug caps however is they are available only in the same shape and angle as the original.  You'll find they don't fit very well on the SOHCs.  They're dirt bike caps. 
Mike Nixon
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Offline OldSchool_IsCool

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Re: The resistor cap plug wire combination mystery
« Reply #12 on: May 13, 2007, 02:53:58 PM »
Quote
still cant get the spark plugs 2 and 3 out though. Dont know where to get a wrench eithe

Use the spark plug wrench in your tool kit, if
you still have it. It really is the best tool for that job.

Here is the plug wrench you need.  You want one that is deep with a sliding Tee-bar handle.  As for places to get it, Sears and most M/C shops will have then in stock.  Size wise, I believe you will need the 12mm unit.  I know, I know, the hex on your plugs are 18mm.  Plug wrenches, however, are sold by the tread size of the plug, not it's hex size.

« Last Edit: May 13, 2007, 03:04:54 PM by OldSchool_IsCool »
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