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anyone explain when resister spark plugs are called for and when they are not?

1970 Commando, Boyer digital ignition installed

all else completely stock

regular plugs ok like Champion N7Y or NGK BP7ES?

or resister plugs of same as above specs?

Digital ignition systems (not just Boyer Bransden) typically require 5,000 Ohms resistance, so you need to fit either 5 kOhm plug caps, or use resistor plugs, but not both.

http://www.boyerbransden.com/pdf/KIT000 ... 00032_.pdf

WITH THIS SYSTEM SUPPRESSED SPARK PLUG CAPS OF 5000 OHM MUST BE FITTED AS RADIO FREQUENCY
ENERGY CAN CORRUPT THE MICROPROCESSOR AND PRODUCE VERY BAD RUNNING.

L.A.B. wrote:Digital ignition systems (not just Boyer Bransden) typically require 5,000 Ohms resistance, so you need to fit either 5 kOhm plug caps, or use resistor plugs, but not both.

http://www.boyerbransden.com/pdf/KIT000 ... 00032_.pdf

WITH THIS SYSTEM SUPPRESSED SPARK PLUG CAPS OF 5000 OHM MUST BE FITTED AS RADIO FREQUENCY
ENERGY CAN CORRUPT THE MICROPROCESSOR AND PRODUCE VERY BAD RUNNING.

+1 (as if L.A.B. needed backup)

From the Pazon Altair sheet..."5k suppressor/resistor plug caps (as supplied) should be used with this system. Resistor spark plugs can also be used. Attempting to run the system without any suppressors will result in excessive radio frequency interference (r.f.i.), which may cause misfiring, bad running, loss of ignition and interference with other electronic/electrical items.
For reliability, copper or steel plug wires (h.t. leads) should be used. Carbon fibre plug wires should be avoided.

the power arch that old britts sells also requires resister plugs/wires

kevbo82 wrote:the power arch that old britts sells also requires resister plugs/wires

Yeah, they claim you need the carbon wires AND the resistor plugs, that seems like overkill to me, but it's running just fine set up like that.

ok 1U3D, so i go get some cool yellow or orange wires, new caps and resistor plugs. clutch, go see buffalo's......then coffee????

ha! it's been a blast so far. love it.........

c

cyclegeezer wrote:Yeah, they claim you need the carbon wires AND the resistor plugs, that seems like overkill to me, but it's running just fine set up like that.

glad to hear it's running good, i just ordered mine today!

I prefer resistor plugs over caps because I've had resistor caps go open short, or infinite resistance twice. Besides, if you want to get a platinum or iridium plug these days then they are all resistor. When these plug failures occurred they took out the dual lead coils I was using leaving me stranded. They were NGK caps, BTW. I don't think you want resistor caps, and plugs, and wires on a Boyer though.

I'm using the Pazon SureFire without any resistor plugs and with standard copper wires. All standard stuff. No problems so far. I don't remember they recommended anything in the instructions or I would have. I usually follow instructions, especially if it's expensive.

Dave
69S

I'm using the Pazon SureFire without any resistor plugs and with standard copper wires. All standard stuff. No problems so far. I don't remember they recommended anything in the instructions or I would have. I usually follow instructions, especially if it's expensive.

Dave
69

new conflicting information !

Dave reports no need for any resister stuff and using a Pazon which I assume is digital?

Controversy in Commando land!

This thread should go viral!

1up3down wrote:Dave reports no need for any resister stuff and using a Pazon which I assume is digital?

The Pazon Sure-Fire isn't digital.

I'm running BP7ES, a Tri-Spark and copper wires.
Is mine digital? And are the plugs wrong?
If so, what plugs should i be using?

Guido wrote: I'm running BP7ES, a Tri-Spark and copper wires.
Is mine digital?

All Tri-Sparks are digital.

Guido wrote:And are the plugs wrong?
If so, what plugs should i be using?

No, the plugs are not wrong, but I take it that resistor caps are fitted?

http://www.trispark.com.au/images/Class ... ooting.pdf

It is recommended that high tension lead suppressor caps be used with this system. Use 5k Ohm caps such as NGK LB05EP.

I'm using MSD street fire wires with non resistor plugs and a Boyer, works well and the RFI suppression seems to work, no problems...bought a V8 set (about $40) with angled caps so I can do a few bikes

Just to make it clear that the resistor cap/plug requirement usually applies to DIGITAL ignitions (and Sparx reg/rec units).

Analog/ue systems, such as Boyer Bransden Micro MkIII & IV, Lucas Rita, Pazon Sure-Fire and Sparx do not require resistor plugs or caps although either can be used.