Resistor Spark Plugs?

[Philbert]

Does it make any practical difference if I use a resistor or non-resistor plug in a chainsaw?

If not, why do they go out of their way to specify the resistor plugs?

Thanks.

Philbert

 

[Trigger Man]

I had that same question on my mind 2 years ago, I emailed NGK and they responded to it by telling me to use the same plug that the Manufacturer used period.

Most small engine shops that I have been to say that the resistor is for radio interference.

I have also read that some ignitions talk back and forth to the resistor, I'm trying to find that info If I find it I will post it.


Here is were I found the talk back info,http://www.sparkplugs.com/sparkplug411.asp?kw=Resistor&mfid=0

 

[Plan-b]

Check this out...

http://www.motorcycleproject.com/motorcycle/text/plugwiretech.html

 

[Trigger Man]

Check this out...

http://www.motorcycleproject.com/motorcycle/text/plugwiretech.html

Thats a good write up.!

 

[CGC4200]

Resistor vs. non resistor plugs

I had one local dealer say there was no difference. I have seen threads
on AS from site sponsor dealers that non-resistor plugs can fry
a ignition module. Why take the chance?

 

[Philbert]

Thanks guys,

I have heard people say that it only has to do with a radio, but the electronic ignition part is pretty interesting. This raises the complementary question: Is there ever an advantage to using a non-resistor plug (or why aren't all plugs now made to be the resistor type)?

Philbert

 

[Tzed250]

.


Most digital ignitions(newer saws)don't like the RF noise that non-resistor generate.


.

 

[Plan-b]

Thanks guys,

I have heard people say that it only has to do with a radio, but the electronic ignition part is pretty interesting. This raises the complementary question: Is there ever an advantage to using a non-resistor plug (or why aren't all plugs now made to be the resistor type)?

Philbert

More so in a high output race application where RF is not an issue.

.


Most digital ignitions(newer saws)don't like the RF noise that non-resistor generate.


.

Neither do pacemakers

 

[CGC4200]

non resistor plugs should be OK with a point & condenser ignition

Except for annoying neighbors with RF noise, why take the chance on frying
ignition on newer saws? The resistor plugs are easier to find & much
cheaper than a ignition module.

 

[Trigger Man]

Except for annoying neighbors with RF noise, why take the chance on frying
ignition on newer saws? The resistor plugs are easier to find & much
cheaper than a ignition module.

:agree2: but some shops I've been to slap a non resistor plug on the counter and say there you go, When I tell them no I want the resistor plug they look at me funny, since then I have been buying my plugs from a hardware store. I hate :censored:shops that don't have a clue.

 

[50:1]

how can you tell if a plug is a resistor or nonresistor plug?

 

[w8ye]

They have a "R" in their part number or you can measure with a OHM meter between the electrode center and the top of the plug

 

[50:1]

so an r in the part/plug number always denotes that it's a resistor plug? thanks

 

[3000 FPS]

So the bottom line according to the article that plan-b posted is the strength of the spark is not affected by the resistor in a resistor type plug and it does cut down on the amount of noise in the spark that can be reflected back into the primary of the coil and then to the electronic module itself and maybe causing damage. If it were me and my saw recommended a resistor plug that is what I would use.

 

[Sagetown]

Thanks for bringing that up Philbert. Not only are you a little wiser, I am too.