Resistor spark plug or non-resistor plug cap

rider55 · 04-14-2018, 12:27 AM

Hi,
My question is going from a NGK spark plug (resistor plug)or(non-resistor plug), do you replace the resistor cap with a different cap?

On Hawk 250

Thank's

Megadan · 04-14-2018, 12:55 AM

If you go with a non-resistor spark plug then it would be a good idea to have a resistor cap on the system. The resistance is there to reduce the thermal load on the coil and also increase the spark duration. I personally prefer to simply stick with a resistor plug, but you can easily switch to an NGK plug cap. I run an XD05F cap on my Hawk, which helps raise the plug wire away from the exhaust as well as shortens it up a good 6 inches. I run a resistor plug, so I removed the resistor from the cap itself and replaced it with a plug of copper. http://chinariders.net/showpost.php?...3&postcount=51

Here is said cap installed.
http://chinariders.net/showpost.php?...4&postcount=52

rider55 · 04-14-2018, 01:11 AM

Hi,
So I have to have at least non-resistor spark plug or spark plug cap.
Your saying both cant be non-resistor .
How to tell if my plug cap is a non-resistor.

Thank's

Megadan · 04-14-2018, 02:09 AM

Quote:

Originally Posted by rider55

Hi,
So I have to have at least non-resistor spark plug or spark plug cap.
Your saying both cant be non-resistor .
How to tell if my plug cap is a non-resistor.

Thank's

The stock Hawk setup is a standard cap with a resistor plug.

If you want to run a non resistor plug, then you will want a resistor cap.

You could run with a non resistor plug with a standard cap, sure. Who knows, it may work fine. Sometimes the resistors are simply used to help reduce electronic noise interference on many modern bikes.

It could also cause idle problems, misfires, run-on, power dips through the rev range, and even poor ignition as a whole. This has a lot to do with the coil and it's own internal resistances. In some extreme cases, the lack of at least one resistor in the ignition circuit can cause the coil to overheat and eventually fail. In the world of old-school bikes, which is basically what these bikes are designed off of, the coils had a higher internal resistance, and needed the plug and cap resistance to slow the discharge rate. In some cases the total ignition system could have over 50,000 ohms of resistance end to end.

This slowing down of spark discharge is part of the reason that eliminating all resistance can potentially cause running issues. The spark actually fires too quickly for the ignition event, and causes the previously mentioned issues.

That said, I haven't tested the coil that comes on these bikes to know if they need said resistance, but you could always try a non resistance plug on the stock cap and see how it goes. The coils are cheap anyway, so if it does fail, no biggie.

That said, if you are thinking to do this as some sort of performance improvement. I can tell you now that, even if you can successfully run without any resistor in the system, it won't make a lick of difference.

rider55 · 04-14-2018, 02:22 AM

Hi,
Thank's for replying.
I'm running a NKG DR8EA plug and the R makes it a resistor plug? I think.
How to check the plug cap to find out if it is a resistor type,because the cap has been changed.

Thank,s

Megadan · 04-14-2018, 02:24 AM

Quote:

Originally Posted by rider55

Hi,
Thank's for replying.
I'm running a NKG DR8EA plug and the R makes it a resistor plug? I think.

The R means it is a resistor plug, yes. You are fine. That is the same plug I am using.

rider55 · 04-14-2018, 02:32 AM

Hi
So the plug cap has to have ohms 5k or more.

Thank's

Megadan · 04-14-2018, 04:32 AM

Quote:

Originally Posted by rider55

Hi
So the plug cap has to have ohms 5k or more.

Thank's

If you want to run a non resistor plug, then the cap should be 5k ohms. Your Resistor plug is also around 5k ohms.

roundhouse · 04-14-2018, 09:21 AM

Interesting, I had no idea. I am sure I have a resistor plug but I will check it next time I ride. Thanks

rider55 · 04-15-2018, 03:53 AM

Hi,
Thank's Megadan
That makes sense.

Thank's

Skateforlife6 · 02-17-2022, 03:02 AM

So this may be stupid but if both resistor cap and plug are 5k ohms, does that make them both together 10k. Is that okay or is it to much resistance? Should it only be one or the other?

**JerryHawk250** · 02-17-2022, 07:41 AM

Quote:

Originally Posted by Skateforlife6

So this may be stupid but if both resistor cap and plug are 5k ohms, does that make them both together 10k. Is that okay or is it to much resistance? Should it only be one or the other?

One or the other and not both.

04-14-2018, 12:27 AM	#1
rider55 Join Date: Apr 2018 Posts: 7	Resistor spark plug or non-resistor plug cap Hi, My question is going from a NGK spark plug (resistor plug)or(non-resistor plug), do you replace the resistor cap with a different cap? On Hawk 250 Thank's
	0

04-14-2018, 12:55 AM	#2
Megadan Join Date: Apr 2017 Location: Omaha, NE Posts: 8,149	If you go with a non-resistor spark plug then it would be a good idea to have a resistor cap on the system. The resistance is there to reduce the thermal load on the coil and also increase the spark duration. I personally prefer to simply stick with a resistor plug, but you can easily switch to an NGK plug cap. I run an XD05F cap on my Hawk, which helps raise the plug wire away from the exhaust as well as shortens it up a good 6 inches. I run a resistor plug, so I removed the resistor from the cap itself and replaced it with a plug of copper. http://chinariders.net/showpost.php?...3&postcount=51 Here is said cap installed. http://chinariders.net/showpost.php?...4&postcount=52 __________________ Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124
	1

04-14-2018, 01:11 AM	#3
rider55 Join Date: Apr 2018 Posts: 7	Hi, So I have to have at least non-resistor spark plug or spark plug cap. Your saying both cant be non-resistor . How to tell if my plug cap is a non-resistor. Thank's
	0

04-14-2018, 02:22 AM	#5
rider55 Join Date: Apr 2018 Posts: 7	Hi, Thank's for replying. I'm running a NKG DR8EA plug and the R makes it a resistor plug? I think. How to check the plug cap to find out if it is a resistor type,because the cap has been changed. Thank,s
	0

04-14-2018, 02:32 AM	#7
rider55 Join Date: Apr 2018 Posts: 7	Hi So the plug cap has to have ohms 5k or more. Thank's
	0

04-14-2018, 09:21 AM	#9
roundhouse Join Date: Sep 2017 Location: N Texas Posts: 709	Interesting, I had no idea. I am sure I have a resistor plug but I will check it next time I ride. Thanks
	0

04-15-2018, 03:53 AM	#10
rider55 Join Date: Apr 2018 Posts: 7	Hi, Thank's Megadan That makes sense. Thank's
	0

02-17-2022, 03:02 AM	#11
Skateforlife6 Join Date: Apr 2021 Posts: 3	So this may be stupid but if both resistor cap and plug are 5k ohms, does that make them both together 10k. Is that okay or is it to much resistance? Should it only be one or the other?
	0