I'm not looking to start a lengthy spark plug thread. But here's the question.
I'm running a 1958 A10 650 with the alloy head. I'm currently using the Champion N4C old school copper and the bike is running great. I'm just curious if anyone has found a working alternative metal plug that runs well. Looking for comments from those who have extensive miles on these plugs. Humorous responses are welcome as well:-) If not then I'll stay with what works.
The last spark plug question on this forum sparked my curiosity.
Champion N4C. Champion RN4C (resistor version same plug). NGK B7ES. NGK BR7ES (resistor version same plug ~4.3k ohms). NGK BR7EIX (resistor version Iridium fine wire plug).
The NGK Iridums have the fine wire only on the tip. The grounding strap is still the same old hunk of metal that is bent over on top and as such will wear as before. Be careful when gapping these plugs as you can knockoff the iridium bit on the plug tip. If they really wanted these to last forever then they would have iridium on both tips. The marketing "claim" is if you ignition system is weak you will get more performance from an Iridium plug. I would rather fix the ignition system.
I've used all of these plugs with good results. Nothing beats proper tuning though.
If it runs great with the Champions then keep running the Champions.
Last edited by Semper Gumby; 08/04/143:22 pm.
Gaggle of BSAs a Honda an old BMW and a Montesa Parking lot Elf in training
Let's put it this way: I think I last put plugs in my Royal Star more than two years ago (probably~10000 miles) and then only because I had an odd misfire that turned out to be a loose connection on the coil. Those plugs had been in for years as well. They were ordinary NGK B7ES's.
A smattering: '53 Gold Flash '67 Royal Star '71 Rickman Metisse '40 Silver Star '37 Rudge Special sixtyseventy Lightboltrocket road racer...and many more.
Iridium and platinum plugs are reputed to work better when they are fouled, so this is a great alternative to getting your jetting right.
I couldn't get on with the iridium plugs, known 3-4 out of 13 go real bad and intermittent , that's not bad for a cheap plug but at £8 each I wasn't impressed. I find NGKs normal B7/8 plugs to be intermittent from one plug running great to another plug not. However I continue to use them. When you get a good one the spark is better than a champion, champions seem more consistent though.
On the subject of Bosch I've been think of trying the W5CC which the inter web tells me is identical to an N4 plug/ B7es
Changing more slightly. My Canam uses the same N3G plug it left the army with. It looks crap as the body is rusty. But I swapped it with an N3C and it didn't start as easy with that. Not sure what the G stands for but worth a punt.
Gold/palladium electrode. Impressing sales talk: "For premium performance, a spark plug having a small diameter Gold Palladium centre electrode. The semi precious metal alloy makes it possible to provide extra performance design features resulting in faster, easier starts, fewer stalls and false starts, reducing fouling deposits and usually longer life. The spark plug design requires less ignition voltage than the conventional electrode type. The design also provides more clearance within the firing end of the spark plug, for better scavenging of fuel deposits and less fouling."
i have to agree on sales hype for the super plugs- just hype ….on real world(in actual service) use since the 70's i have found that ngk standard plugs last and work the best….champions,ac,others have fouled where ngk standards have not!
No modern exotic plugs do make a big difference . Now if your engine is in perfect trim, ridden regularly ,the carb is perfect and you reun real 1970 petrol they will not make any difference.
However when you wake up & find yourself in the 21st century where petol is a thing of the past , your bike might get ridden once or twice a month, fuel varies in viscosity & density on a daily basis rendering correct mixtures near impossible to maintain. Then the little help from exotic metal plugs does make a difference.
I used to run a small transport company and in the fleet were my old SR 500's the I had been using as an owner driver for many years before taking on some partners & running our own company. Now I used to get around 3 set of rings out of a single piston on the SR's if I caught the drop in CR ( thus ring wear ) early enough. If I didn't they would start fouling plugs at anything less than 110 psi and it would be new piston time. However platinum plugs would allow that enine to run quite well for another 20,000 -50,000 km by which time the cr would be in the high 80's , the smoke from the exhaust worse than a Bantam but the plugs rarely fouled up to the point the bikes would not start .
So there you have it. Keep your bike to the standards of John Healey and they are a waste of money Live in the real world then they may be worthwhile . The local Notrun owners just about all use them exclusively. Horses for courses