New Spark plug Wires

Ok, so now I'm making progress. I cleaned the electrical connector talked about elsewhere on the forum, took my spark plug caps off, disconnected the wires and re-seated them into the caps and wonder of all wonders, my bike runs much better. No more hesitation off idle and pulls strong everywhere. Woohoo :clapping:

It does still have an irregular idle though, like one cylinder is occasionally dropping out, but I am very happy.

When I had the plug wires off, I wasn't all that impressed with their general condition. They screw into the cap and on a couple it didn't appear that many strands of wire were making contact. Probably just a "little" bit nit picky, but I want to change the wires (not the caps) and hopefully get the sewing machine smoothness I used to have.

I went to Ron Ayers to order up the OEM part and to do so you have to order the cap assembly (wire and cap) for $45 each. $180 seems high for 4 spark plug wires.

Long intro to ask the question, are these wires special or should I be able to go to my local auto parts store and get some wires?

Thanks,

Clay

The plug wires are integral to the coils. There is no cap connector at the coil end, so there is no plug wire by itself available. The plug boots are separate.

You have two coils, one for the #1 and #4 cylinders, and another for the #2 and #3 cylinders. If you want to replace the boots as well, there are obviously 4 of them, all identical.

To replace all four wires, get both coils. The wires are part of that assembly. Use your old boots unless you have some reason to doubt their integrity. I've found the coils for about 60 or 70 bucks each. A dealer price would be about 90 to 100 dollars, so that sounds about right for both coil assemblies.

This is what I would do before laying out big bucks for new wires, etc: Cut about 1/4 inch off the ends of each wire to expose new wiring and reattach to plug caps. If the miss is still there, raise the tank and start the engine, look for sparks from the wires in a dark garage or at night. If you see any, it would be a good indication that the wire needs to be replaced.

Clean the wires with a rag and WD40. Dirt can be a conductor. Try to feed the wires so they aren't in direct contact with the engine or frame in case they are grounding out. A split piece of fuel line can be slipped around the wire as a standoff.

This has worked for me in the past. Being a cheap bastage is fun, if it works.

rcsnclh said:

Ok, so now I'm making progress. I cleaned the electrical connector talked about elsewhere on the forum, took my spark plug caps off, disconnected the wires and re-seated them into the caps and wonder of all wonders, my bike runs much better. No more hesitation off idle and pulls strong everywhere. Woohoo :clapping:
It does still have an irregular idle though, like one cylinder is occasionally dropping out, but I am very happy.

When I had the plug wires off, I wasn't all that impressed with their general condition. They screw into the cap and on a couple it didn't appear that many strands of wire were making contact. Probably just a "little" bit nit picky, but I want to change the wires (not the caps) and hopefully get the sewing machine smoothness I used to have.

I went to Ron Ayers to order up the OEM part and to do so you have to order the cap assembly (wire and cap) for $45 each. $180 seems high for 4 spark plug wires.

Long intro to ask the question, are these wires special or should I be able to go to my local auto parts store and get some wires?

Thanks,

Clay

Click to expand...

Have you checked the resisters in the caps that snap onto the plugs? If not there is a large headed screw inside the cap(the end of the plug goes inside this screw, plug ,whatever. If you take it out there is a small resister (Gray I think) and a spring approx. 1' long check for carbon tracking etc., The resistance should be around 10,000 OHMS. I have even used longer springs and left out the little pills on dirt bikes. And I really don't know why we need resister caps and sparkplugs also.

Hope this helps! Bernie

So is this setup you speak of different from the Gen II models? I took the boots off the plugs to change plugs and didn't see any of these items on my 06. Or am I missing something here? PM. <><

Have you checked the resisters in the caps that snap onto the plugs.....And I really don't know why we need resister caps and sparkplugs also.

Click to expand...

The FJR does not have resistors in the caps like some other bikes do, the FJR uses high voltage cables that have resistance built into the wires. The resistance is there to prevent Radio Frequency Interference (RFI). With unrestricted current, the spark plugs arcing will spray out 'noise' like little RF transmitters. The noise occurring in the Radio Frequency band will cause any radios in the vicinity to buzz, and may interfere with other electronics as well.

Putting the resistors in the plug caps lets you use conductive high voltage cables of any reasonable length. When the high voltage cables have resistance built in, the resistance will change with length of the wire. Since the FJR's high voltage wires are molded into the coil the wire lengths are controlled, therefore the resistance is controlled, but at the expense of having to change the coils to fix a wire problem.

Pull the wires associated with coil #1 off the plugs, put your ohmmeter probes up inside the plug boots; read 12k to 18k if all is well. Same is true for coil #2. This isn’t a full, definitive test for the caps, wires and coil but it is an important test to detect major failures.

While I was changing the plugs today I measured the resistance of the circuits.

1 to 4 series resistance = 35.7 Kohms (not including spark plug resistance)

2 to 3 = 36.4 Kohms

Don't know what portion of the resistance is the high voltage coil.

Each spark plug includes an internal resistance of approximately 4.5 Kohms.

The plug resistance decreases a bit over time. Old plugs' resistance averaged 3.96 Kohms.

I put some silicone grease on the larger diameter upper portion of the plug caps hoping that they'll be a bit easier to remove next time. Don't see how any debris could get into the cylindrical area above the spark plugs (blast of compressed air optional).

Gen I -- Spark plug caps 10k ea; ignition coil secondary 12-18K. Reading through TWO plug caps (1-4 & 2-3) should be 20k + 18k from the ignition coil = 38K. Dunno why I thought the resistance was in the plug wires, gotta go back and do some reading. The FSM says to pull the plug caps off the wires(!) and ohm them individually.

How is the plug cap electrically connected to the wire? Looks like a sheet metal screw in the cap which threads into the opening in the wire end. CW or CCW to install the cap on the wire? The screw makes contact with the wire strands and the electrical connection is made. Not much of a physical connection though. Not supposed to be pulling on the wire though, are ya!

Constant Mesh said:

How is the plug cap electrically connected to the wire? Looks like a sheet metal screw in the cap which threads into the opening in the wire end. CW or CCW to install the cap on the wire? The screw makes contact with the wire strands and the electrical connection is made. Not much of a physical connection though. Not supposed to be pulling on the wire though, are ya!

Click to expand...

CW, just like a right-hand screw.