Coil and Wires?

[mmarrs01]

Hello Everyone,
Over the week end I did a tuneup of my 85 FJ1100. I had been noticing a lot of back firing at low RPM and other performance problems.
While changing my plugs I had noticed my wires were in bad shape. I did a temporary fix on them by rapping them in electrical tape and making a tool to keep the wires away from each other and the motor and frame. It worked and is running much better.
My Question is can the wires be replaced without changing the coils? If not where is the best place for replacement coils and wires?

Thanks!
Mark

[andyoutandabout]

Check the files for the Fj approved coil mod which really helped my bike. Maybe some clever clogs can post a link, but its in there somewhere with diagrams and pictures that make the job a doddle.

[Pat Conlon]

There is nothing wrong with the stock FJ coils. If they check out ok, reuse them.
If you want more spark from your coils, increase the supply voltage via the coil relay mod: http://www.fjowners.com/index.php?topic=1755.0

If you want to go to aftermarket coils you want 3 ohm coils like Dyna Green 3 ohm coils. eBay is your friend.
Beware: The Dyna Greenies are larger than the oem FJ coils so getting them to fit can be kind of a pain.

Wires: If you are going to use your stock coils you can replace the wires with 7mm solid core wire. Never use solid core wire without resistor caps.
You will need new NGK resistor plug caps, available at RPM.
You have to twist hard to get the oem wires out of the oem coils.

If you are getting an intermittent ignition stumble (like I was) look at the power circuit to the igniter box.
This power circuit runs thru the right handlebar run/stop switch. The problem could be in the run/stop switch.
For testing, I ran a temp. jumper wire from the battery to the igniter box and my problem went away, so I knew in general what the problem was...
I just didn't know exactly where. I finally traced it down to a bad wire from the multi pin connector (under the fairing) to the igniter.

All this was (of course) after I spent $$ installing new Dyna coils, plugs and plug leads. The problem was intermittent. The worst type of electrical bug.

Hope this helps.  Pat

[balky1]

There is nothing wrong with the stock FJ coils. If they check out ok, reuse them.
If you want more spark from your coils, increase the supply voltage via the coil relay mod: http://www.fjowners.com/index.php?topic=1755.0

If you want to go to aftermarket coils you want 3 ohm coils like Dyna Green 3 ohm coils. eBay is your friend.
Beware: The Dyna Greenies are larger than the oem FJ coils so getting them to fit can be kind of a pain.

Wires: If you are going to use your stock coils you can replace the wires with 7mm solid core wire. Never use solid core wire without resistor caps.
You will need new NGK resistor plug caps, available at RPM.
You have to twist hard to get the oem wires out of the oem coils.

If you are getting an intermittent ignition stumble (like I was) look at the power circuit to the igniter box.
This power circuit runs thru the right handlebar run/stop switch. The problem could be in the run/stop switch.
For testing, I ran a temp. jumper wire from the battery to the igniter box and my problem went away, so I knew in general what the problem was...
I just didn't know exactly where. I finally traced it down to a bad wire from the multi pin connector (under the fairing) to the igniter.

All this was (of course) after I spent $$ installing new Dyna coils, plugs and plug leads. The problem was intermittent. The worst type of electrical bug.

Hope this helps.  Pat

Pat,

just a bit of off-topic, do you know if the straight plug caps from NGK will fit on an 84/85? Or the have to be bent?

Ivan

[Pat Conlon]

I'm currently using the Dyna (resistor) carbon core wires with straight (non-resistor) plug boots and they work ok.
The plug wires need to be longer with the straight plug boots.

I have used Randy's NGK plug boots (angled) on other FJ's and they fit just fine re-using the stock oem plug wire.


Therefore, to answer your question, if you are re-using your stock plug wires, no, they are not long enough for the straight plug boot.
If you are installing new plug wires, yes, you can use the straight NGK plug boot with longer wires.

[racerrad8]

Straight plug boots also interfere with the cooling ducts over the head.

Randy - RPM

[whyzee79]

This sounds like a stupid question but why do you have to run the resistor caps?  Is there something in the iggy system that needs it?  I am also looking  to replace my wires and have accel solid 7mm copper core wire. 

[ribbert]

......I'm currently using the Dyna (resistor) carbon core wires ....

The use of these requires some caution. Almost all the problems you are likely to have with them will occur before you even fire it up - installation.

If fitting them requires heavy handling, twisting, bending, forcing etc, you have more than likely already broken the carbon core.

Noel

[Pat Conlon]

Very true Noel!  The carbon core wires are nowhere near as durable as the wire core wires. Pulling the plug boots off, you have to be very gentle on how you handle them.
I only used them because they (a new set) came with the Dyna coils. I would never reuse an old set of carbon core wires.
Any wiff of trouble from these puppies and they are coming out to be replaced with 7 mm copper core wires and NGK caps.

Whyzee: Yes, this has been what I've been told. The electrical noise from non resistor plug leads will interfere with the TCI or DCI functions.

I've always wondered if this is true?  Has anyone run their FJ with solid core wire and non resistor plug caps?

[ribbert]

I only used them because they (a new set) came with the Dyna coils. I would never reuse an old set of carbon core wires.

I suspected that was the case but my post was a general caution to anyone thinking they might be a good "upgrade"

It is the reason they are sold as make/model specific sets with fittings, to minimize handling. Even then great caution is required.

Noel

[Earl Svorks]

     A few years ago, I built a sort of a'Dyno' for testing ignition coils. There are some pix on this site of the thing in action.  At one time I grabbed a handful of various coils (I had dozens on hand) One by one I spun them up. I was able to identify these coils as to the bike they came off. I was a little surprised to see that the FJ coils produced secondary output voltage that was not surpassed by any other OEM coil that I tested. The Dyna coils may be better but I didn't have any to test at the time. I may have one of those on hand now. If I find one, I'll test it and post the results. The highest voltage I ever recorded
came from the coil that was found in the Chev HEI  distributor. That one came very close to making
  40,000 volts. that's a fat blue spark about an inch long.

[Pat Conlon]

Simon, that information FJ oem vs Dyna green 3 ohm coil output would be very interesting.

[FJ_Hooligan]

Simon, that information FJ oem vs Dyna green 3 ohm coil output would be very interesting.

When I replaced my stock ignition and coils with Dyna components, the difference was immediately noticeable.

The start button became more of a start switch.  No cranking required.  A quick touch of the start button and the engine jumps to life.  Stone cold or hot soaked makes no difference.

[Alf]

When I replaced my stock ignition and coils with Dyna components, the difference was immediately noticeable.

The start button became more of a start switch.  No cranking required.  A quick touch of the start button and the engine jumps to life.  Stone cold or hot soaked makes no difference.

Exactly the same performance that making the cheap relay trick with the OE coils.

Years ago I asked Randy about the OE coils performance and he told me these are the best available coils, like Earl Svorks wrote

Regards