FJowners.com

General Category => Maintenance => Topic started by: 4everFJ on April 10, 2016, 01:34:16 PM

Title: Plugs, caps and resistors?
Post by: 4everFJ on April 10, 2016, 01:34:16 PM
So, the OE specifications for the FJ1100 lists spark plugs with resistors (NGK DPR8EA-9).

I am about to replace the old OE spark plug boots/caps, but I am not sure if I should get them with or without resistors?

Since the plugs already have resistors in them, I have alwyas been of the impression that you should use caps without resistors. However, it seems difficult to find caps without resistors and various suppliers lists caps with resistors for the FJ 1100.

Anyone who knows what is correct?
Title: Re: Plugs, caps and resistors?
Post by: FJmonkey on April 10, 2016, 01:37:22 PM
Give Randy or Robert a call at RPM.
Title: Re: Plugs, caps and resistors?
Post by: 4everFJ on April 10, 2016, 01:52:47 PM
Quote from: FJmonkey on April 10, 2016, 01:37:22 PM
Give Randy or Robert a call at RPM.

Nah, the 9 hours time difference makes that not so practical..  :smile:
Title: Re: Plugs, caps and resistors?
Post by: FJmonkey on April 10, 2016, 01:57:25 PM
Quote from: 4everFJ on April 10, 2016, 01:52:47 PM
Quote from: FJmonkey on April 10, 2016, 01:37:22 PM
Give Randy or Robert a call at RPM.

Nah, the 9 hours time difference makes that not so practical..  :smile:
Then let me rephrase my intention. Communicate with them, they respond by email as well.  It is also quite likely they will reply to this post.   :good2:
Title: Re: Plugs, caps and resistors?
Post by: racerrad8 on April 11, 2016, 10:57:02 AM
Since the spark plug wires are solid core wires, resistor plug boots are required.

I personally will only use the stock Yamaha spark plug boot.

I have found the brass portion of the NGK ends are too soft and wear out. We had a problem with the NGK on the race car, where the engine is mounted sideways. The air flow across the # 4 & 3 cylinder would blow the plug wire off the plug at speed. Went back to the Yamaha boots and that has never happened again.

I do sell a lot of NGK boots as the air flow issue is not a problem on the motorcycle. I think I sell more of those due to the cost of the Yamaha boots. But if the Yamaha boot has finally worn out after 25+ years that is a good investment.

Yamaha Spark Plug Boot (http://www.rpmracingca.com/proddetail.asp?prod=Ignition%3ASPB)
NGK Spark Plug Boot (http://www.rpmracingca.com/proddetail.asp?prod=Ignition%3ANGKBoot)

Randy - RPM
Title: Re: Plugs, caps and resistors?
Post by: 4everFJ on April 11, 2016, 01:12:23 PM
Thank you Randy.

I checked the OE caps and they have a 10 Kohm resistor. So, no problem fitting a 5 Kohm cap together with the 5 Kohm plugs. If anything, it should give a slightly stronger spark.