Plugs and caps -resistor or not?

[daxman]

Hi all
I think I've isolated a running issue to at least one dodgy plug (type B8ES). The plug cap is a 5k ohm type and sparks fine with a random DR8ES i had lying about (testplug laying on head points opened/closed with thumb).

Ismy current plug/cap selection ok? Or should I try and better combination of plug/resistor/cap?

PS thought I'd solved the issue yesterday when I closed the plug gap down to 20 thou rather than my assumed 25 thou but no dice on that plug.

Cheers

[johnakay]

plugs all ready have built in resister so I'm told.
no need for resisters these day most appliances have them built in.
just a rubber cap will be just as good and cheap.

[jabcb]

What bike are you asking about?

[karl pa]

I go with non resister plugs and non resistor caps.
NGK has an R in the number if it is a resister plug, (example BR8ES)
You don't want resister plug and resister cap together.

[Alan H]

A 'normal' resistor plug cap is 5000 ohms, unless you have a pei system, you don't need them. As Karl says, a plug with an 'R' in the designation has a resistor ( as well as the plug gap!), so you don't need one of those either if you run points.
Every resistor gives a smaller spark on points, but is needed on pei so as to minimalise spiking and give a 'smoother' spark - so if you have an electronic tacho, it'll read true and not what it wants.

20160902_180156.jpg

Like this on my 550A coming down from the 'Creg' on the IOM a few years ago.
104.6mph at nearly 6pm with18410 rpm?..... Hmmmm..........
And no, I didn't realise there was a speed limit on non race days..
Ooops!!!

[daxman]

Hi All

I went with some new B8ES and B9ES I was in a hurry and Halfords only had one of each so running 'odd' plugs ATM on my GT250A.

Now I read that Iridium could be the way to go but it seems these are only available form NGK at least 'with' resistor i.e. BR9EIX or did I get that wrong

Cheers

PS I think even 'Hicky' would struggle to get round the Creg at 104!

[jabcb]

The non-resistor fine-wire high-performance plugs were B8EG & B8EGV, but they were discontinued.

I use either resistor plugs + non-resistor caps, or non-resistor plugs + resistor caps.

[Alan H]

PS I think even 'Hicky' would struggle to get round the Creg at 104!

Oh, it wasn't round the Creg right hander!
We'd followed an IOM police car for a couple of miles from before Kate's Cottage at quite a steady speed, and he - plus several others - turned left into the Creg car park, so as the van in front of me (and then the only vehicle between me and an empty road!!) went around the circuit right hander, I thought 'sod it' (as you do) and gave the bike beans bigtime downhill for the benefit of my fan club sat drinking on the grass banking ( ), slowed a bit for the left hander and did the beans again until I got to Hilberry. I was told after that all this was a 60mph limit, but I never saw the sign ossifer - honest!
The bike was undergeared at the time and now has a 3 teeth smaller back sprocket so should be even quicker!