Spark plugs

Have a look at:-

https://www.nortonownersclub.org/support/technical-support-general/spark-plugs-for-nortons

As long as the reach and heat range is ok, there is very little if any benefit in 'racing' plugs. 

I use the standard Champion plugs in my Commando, NY7c (I don't use much because of the weight) and the standard Champion N4c in my 650ss.

In both cases they are generally first kick starters.

I have never had a failed Champion plug, though I did run a test on a model 50 (N5c) and it ran for almost 7,000 miles before  failing. (I always carry a spare N5c. Plug changed and here's to another long stint of fit and forget.

Hi Barry

I'm another convert to Brisk spark plugs.

Marvelous on the 650SS

Cannot make any sense of the modern Champion plugs on my bike. 

Hop that helps

Tim

having looked up Brisk website, it says L14YC plug for all Commandos, however that number does not appear in the summary of NGK equivalents at top of list, and isn’t searchable on website either. (Norton list is on page 94 of huge model list, by the way)

Tim,

Please can you explain what you can't make sense of.?

N4 is N4 and mine goes a treat too. They are easy to buy locally and at a good price.

Hi Neil

Good to hear from you. 

My 650SS was going through modern Champions after hardly 100 miles.

Read an article in OBM and ordered a couple of Brisk to try. No problem just as spark plugs used to be in "t' olden  days". Ordered some spares and have not required them yet, through setting up a single Amal MK2 Concentric. Just keep taking them out for various jobs (eg, valve clearances) cleaning and refitting them.

I don't dispute Champions are working in your bike but didn't last 5 minutes in mine. Also tried NGK, no good for mine.

Hope that helps.

Our bikes almost have "personalities" of their own, so we have to be open-minded. 

Tim

OK Tim, fair comment.

Some free Amal  notes I received some years ago stated that no two bikes are the same and I guess that applies to plugs as well.

Mine is a bitsa and set up as a Mercury, sounded like a bag of nails for over 1,000 miles when first commissioned,  but coming up to 3,000 miles it sounds quite normal. all on the same plugs.

Just my experience, that's all.

Hi Neil

I'll start a thread on Heavy Twins Forum pGe

I’ve had new champion and NGK plugs fail recently, the champion just failed completely, the NGK would start and tick over but misfired badly at higher revs. Any time I have a running problem the first thing I now check is the plugs!

I have just switched from very expensive fine wire plugs that kept sooting up to a pair of KLG  old stock plugs with very glossy  pink insulators  that self clean once given a bit of stick .I am guessing that the sooting is caused by wet sumping and use of too thin 10/40 oil . I will switch to a 20/50 fully synth soon .

I am currently using Brisk L14YC spark plugs in my Mk.III Commando; they are working fine, and they do not soot-up like the previous NGK ones.  On the other hand, I have a 500 single which starts first kick and runs brilliantly on a NGK Iridium spark plug, the one that is intended for the Commando.  Still using .025 gaps and all is fine. It's really only the tip of the electrode that you need to worry about, even though the NGK ones look very sooty. I occasionally clean the Brisk ones in my ultrasonic cleaner and they look like new ones.  Your mileage, use and satisfaction with your spark plugs may vary; Good Luck!

I use brysk  L14Yc on my commando for all time and works much better than ngk and so on

i use brisk on my 650ss too but  i have rebore threads for smalles diametter and i use long version of brisk same are used on modern BMW

https://www.rajce.idnes.cz/freebiker/album/hlava-650-ss-norton

Hi Michael ,  I have a selection of 106 needle jets from brand new to old used and some 105 ,s which are undersized for our use but i have reamed out to 106 .  I recently found out that for some reason 106 marked jets are now being supplied 1065 actual size  as a normal !? .I suspect this is because all fuel now contains ethanol and tends to run weaker and our suppliers think they know best but dont for some reason want to tell us what they are doing in case we poor lambs get confused.  I also do my own cross drillings because we sometimes get sent two stroke jets when they are out of stock of the correct item  and dont think we will notice.  Hope you are not now confused !!

I have a collection of both Champion and NGK plugs that I used in my Matchless G9 twin, 3 sets of which one has failed in each set.

Testing them out on the bench revealed one spark plug uses the gap proper, the "duff" plugs find a more easier spark path within the body somewhere I cannot see even in the pitch dark!

These plugs are new and not so old as to be expecting this outcome, I do less than a thousand miles a year on the bike.

Most if not all of the scenarios mentioned on this theme, I have experienced at one time or another and have changed the dual coil 4 times to no avail due to failing spark plugs.

(The coils are faultless by the way)

The ignition system is a wasted spark set up which took me while to understand why the engine would run on one cylinder all day long if left to its own devices when at other times the fault would clear and my journey would precede without any more fuss.

I am now about to try some Bosch equivalent plugs (weather permitting) Annoying thing is they have Made in China embedded in the body.

It has been muted that; modern plugs are not glazed in the places that prevent tracking and allows contaminants to fill the gaps and set up a tracking path.

It has also been suggested that maybe it is a good idea to keep old spark plugs that were working perfectly before changing them during routine maintenance and using them to replace nonfunctioning, "New" plugs!

The most irritating part of my experience with bad spark plugs is finding an outlet that one can genuinely believe, are selling the real "McCoy".

I can honestly say I've never had any problems with any of the plugs I've ever fitted. Just lucky I guess.

Perhaps I shouldn't have wrote this the plug pixie will probably ensure I have my fare share of failures from now on.

Although I always buy mine from the Green Sparkplug people so I'm sure they're genuine. NGK work fine in all my bikes.

Hello Dave. 

You may well shiver and expect the wrath of the "Plug PIxie" as I too have bought some new plugs from the Green Spark Plug company in the hope that they will be genuine Bosch items and help me put some non- misfiring miles on my Matchless. So, seal up your bike space just in case

the little devil is seeking out another biker to pester.

Sincerely hope it's not you.

Honest.

Are these plugs not meant for a rice burner?