441 Victor Spark Plug Evolution?

[iansoady]

https://www.classicbikeshop.co.uk/ngk-b7es-spark-plug.html

https://www.sparkplugs.co.uk/ngk-spark-plug-b7es-1111-2

I've tried Brisk plugs and found them no better than NGK or Champion.

[Derek996]

...Does NGK even make non-resistor standard plugs anymore?

Yes, I get NGK B7ES from a local motor factor.

[Derek996]

https://www.classicbikeshop.co.uk/ngk-b7es-spark-plug.html

https://www.sparkplugs.co.uk/ngk-spark-plug-b7es-1111-2

I've tried Brisk plugs and found them no better than NGK or Champion.

And they are very expensive.

[Daz]

 I was going through spark plugs at an alarming rate, tried NGK, new Champion, new old stock Champion, Denso, new old stock Lodge, iridium and gold paladium and anything else I could find! Some developed a misfire after around 50 miles, none were surviving 500 miles. I bought some Brisk plugs and they've been in for well over 2000 miles and are still working perfectly. They were more expensive but they have saved me the expense and inconvenience of constant plug changes. I'll be putting them in everything from now on.

[Big Diehl]

Never heard of Brisk Plugs! Do they make non-resistor plugs? Do you have access to cross reference chart that includes Champion N6Y, or NGK B7RES?  Thanks for the input.

[idie]

The problem with modern plugs is that the porcelain is no longer glazed. This means if your vehicle doesn't immediately start or you flood the carb to start petrol will soak into the porcelain and short out the spark. Brisk spark plugs are glazed so reducing the problem.

[iansoady]

Never heard of Brisk Plugs! Do they make non-resistor plugs? Do you have access to cross reference chart that includes Champion N6Y, or NGK B7RES?  Thanks for the input.

David Angel of F2 motorcycles (Brisk supplier) is helpful re equivalents. https://www.f2motorcycles.ltd.uk/

[Big Diehl]

Interesting information, at what point did the practice of glazing the porcelain cease to happen? I just purchased a bunch of old stock Champion N6Y plugs. As far as tell, that plug has not been produced for a number of years.

I am away from the bike for another week to begin experimenting with all of it. My plan is to begin with the N6Y plug, which is recommended by the factory manual. At the same time I am going over the carb one more time with a couple of new components (needle jet, and needle). At that time I will also check the timing again. After all this, and if my results are the same, I may think about moving to leaner overall jetting, and perhaps changing the plug altogether.

My original question was about why BSA went to cooler plugs with the later model Victor. The later model Victor had a battery, longer pipe, and the carb was jetted differently (richer main jet, smaller needle jet and used the 3rd clip position on the needle).

[limeyrob]

I wonder if small improvements to power and the smaller needle jet lead to hotter running in the mid-range. Of course the one thing you don't want on a bike that hard enough to start is a cooler plug!  Its also possible that the factory were getting reports of plug problems with the hotter plugs.

[Big Diehl]

That is definitely possible!   I will reach out to other '67 Victor owners on other blogs to find out what they are using.