TOPIC:

If you have a motorcycle with factory electronic ignition and stock coils...do you really need resistor type plugs if you have resistor spark plug wire boots? Seems like resistance would stack or something with the wrong setup. I would think it would be especially important if you have weak coils...Can anyone straighten me out on this?

(((((BUMP)))))) Any help here guys???

Do you need resistor type plugs if you have resistor spark plug boots?

I do not need resistor type plugs with resistor boots. Neither do you. ;-0
-Duck

Post edited by: Duck, at: 2006/02/28 03:25

I run non resistor plugs and non resistor plug wire boots. I have an 82 KZ-1000 CSR with the stock electronic ignition.

Runs Great.

Spock

What is the purpose of the resistor plugs/caps? Isn't it just to reduce electronic noise or something like that? I need to learn this stuff soon because I plan on a full ignition upgrade before spring, and I need to know what to order from Jeff.

I think the only reason you would want to run resistor plugs/wires is if you had a radio or communicator. The resistance helps cut down on radio interference.

Resistance in the secondary side of the ignition circuit increases the duration of the spark. This may or may not make any difference because of variation in spark-mixture interaction in different engine setups.

IMO you can't beat a good CDI system.

-Duck

If you use non resistor wires, caps, and plugs, you are going to irritate anyone near you trying to listen to AM radio

I am not aware of any CDI (Capacitor (or Capacitive) Discharge Ignition) kits being available for the KZ's, the stock KZ electronic ignition is not CDI.
Maybe Lou will expain the difference

It is very possible that a weak coil will work with non resistor but not work with resistor wires, caps. and plugs. Generally just one of the three is enough.

Post edited by: steell, at: 2006/03/05 11:14

Thanks Steve...that's what I thought.

Have a look here if you want to see the physics.
Example shows charging time as a function of resistance.
Discharge time is likewise increased with increasing resistance leading to a longer duration spark.
hyperphysics.phy-astr.gsu.edu/hbase/electric/indtra.html#c1
-Duck

Sheesh, just make it simple
It takes increased voltage to overcome the additional resistance and jump the plug gap, and obviously it's going to take a little bit longer to increase the voltage to that point. But all you need is sufficient spark to ignite the mixture under all operating conditions, anything more is just a waste.

I have never seen any advantage to a long duration spark (in normal motors), once the mixture is ignited everything near the plug is already going to be burning and the remaining spark duration is not going to be doing anything.
In a situation where you have a poorly designed combustion chamber with too much swirl that is actually blowing out the spark, then an extended spark duration (or even multiple spark) may be needed, or if you are running extremely high compression with special fuels, then it may be needed. But if you are doing that kind of stuff then you are on the "Bleeding Edge" and better know what you are doing anyway