correct spark resistance

[crassius]

the plastic ones are zero resistance and a direct (but weaker) copy of NGK model LZFH

never seen a rubber cap that had extra resistance built in, but maybe there are some

 

[Frankenstein]

the plastic ones are zero resistance and a direct (but weaker) copy of NGK model LZFH

never seen a rubber cap that had extra resistance built in, but maybe there are some

Weaker like cheaper, right?

 

[Steve Best]

Most often it is resistance wire being used, or at least being the choice. It seems to be a "no-brainer" that I want good copper wire and not that flakey carbon stuff right?

Well, not so fast.
Until the spark jumps, there is no current, and resistance is not much of a factor UNLESS you have a fouled plug that is conducting. In that case the copper wire will bleed voltage off before the jump. Resistance plugs and/or wires work better under fouling conditions. They allow for a higher voltage spark.

Another issue is the current through the coil. Yes it can be too much if copper is used, but there is another effect of a "bouncing" AC voltage in the coil after the spark. Resistance helps to dampen this out. It is especially important at high rpm.

Most coils are pretty tough, our bikes will live and run with either resistance or non-resistance components and hard to tell the performance difference between them. Although non-R seems to make intuitive sense, I'd suggest to lean toward resistance components where you can.

 

[crassius]

Weaker like cheaper, right?

actually, if one shops around the NGK costs less - never had an NGK cap crack or lose it's brass connector like the chinese ones always do

 

[Frankenstein]

actually, if one shops around the NGK costs less - never had an NGK cap pub or lose it's brass connector like the chinese ones always do

Cheaper like worse made

 

[wickedest1]

Personally I've found the ngk non-resistor caps work very well in conjunction with a good quality copper core wire. But as of lately i seem to be coming across horrible quality cdi boxes. I ordered 5. All from different vendors. All but 1 worked. I played with resistor and non-r caps. All but 1 cdi box showed infinity resistance. That 1 is the only functional box. It seems that even though our little lovely hobby is growing in perspective and popularity, the quality is still as hit and miss as it's always been.

 

[butre]

there's resistance in the spark gap itself. if you run a correct wide spark gap then you don't need any resistor parts in your ignition system.

 

[gary55]

Personally I've found the ngk non-resistor caps work very well in conjunction with a good quality copper core wire. But as of lately i seem to be coming across horrible quality cdi boxes. I ordered 5. All from different vendors. All but 1 worked. I played with resistor and non-r caps. All but 1 cdi box showed infinity resistance. That 1 is the only functional box. It seems that even though our little lovely hobby is growing in perspective and popularity, the quality is still as hit and miss as it's always been.

I am having the same problem with cdi's that will run for a short period before failing or not run at all. I just returned 5 cdi's that I bought to replace the faulty ones in the kits and they were bad as well.

 

[crassius]

that is really weird - had a customer buy three CDIs before I could get him to bring some back for the free CDI testing I do - all three were good - his problem was that he bought one of those home depot lifetime guaranteed spark plugs and it was failing badly in a 2-stroke

I once had a bad magneto that intermittently failed, so that sitting for the amount of time needed to hook in a new CDI was enough to get it sparking again - testing the CDIs that I thought had failed showed them all good.

 

[gary55]

On these I did a double test to make sure I was coming to the right conclusion. With 2 failures I took a cdi of a good running bike and wired it in. The bike fired up and ran perfectly. I tried each of the others that I sent back. Some would sputter but not run. One caused a backfire. One did nothing at all. Then putting the proven one back on and the bike ran perfectly again. So while all the other components remain the same they were the only variables to cause the failure to run. I do remember someone saying they have a means of testing for failure over a period of use and had one test good initially then fail a few minutes into the test.