ngk plugs discontinued (updated)

[LowRyter]

I have an aircraft spark plug cleaner/tester that I've made an insert to test 14mm plugs. Other than finding an occasional bad plug out of the box (Champion mower plugs) it's kind of useless on a $2 plug. It's kind of handy on a $50 aircraft plug, though. 

I have half dozen old ones squirreled away.  That'd be about $12 worth.   

[s1120]

My grandfather who was a NYC cop spent the last few years working in a NYPD garage as a mechanic and supervisor rather than a desk job after getting hurt while serving as a motorcycle officer in upper Manhattan.  He was one of the lucky few to ride the old Indian police bikes in the 50's and 60's.

Anyhow, your recalling Dr. John reminded me of a trick he taught me back when I was a kid, that increasing plug gap on an air cooled engine or high powered motor would result in more power and torque, but you had to have a healthy fuel and ignition system, or you would hobble the motor. He was also a fanatic about indexing the plugs to get as ideal and equal combustion as possible. Man I miss him.

I prefer the R plugs to non R plugs with or without R caps. They result in a cleaner spark (as was stated earlier) due to the resistor.

Use what makes you most comfortable.  I've had similar performance from ND and NGK plugs, but prefer old school copper NGK's or BOSCH to just about anything.

My stepfather raced dirt track back in the 50's, and did a lot of testing getting the most out of the old flathead fords. He also found that they ran stronger and stronger till the weak ignition's of the day would fail. He always said he wished he had the later CD, or electronic ignitions back then.

[sign216]

Let me get this right; are people suggesting resistor plugs for old points based ignitions?

I search out non-resistor plugs for old ignitions, esp. kick start magneto bikes.  I bought a used '69 Benelli 350 single (actually sold by Wards Riverside), in very good, but non-running condition.  It had spark when bought.  I refreshed the bike overall, put in a fancy Bosch thin-wire precious resistor metal plug, kicked it and kicked, but no spark.  Put in the orig. 50 yrs old non-resistor Marelli plug, and BAM!  Nice spark. 

If may have been a plug gap issue, but I bet the resistor didn't help.  The orig. plug had a 0.026" air gap that the engine called for, while the modern Bosch resistor plug had a much bigger gap.

[Mike Tashjian]

Gapping the new plug to .026 would possibly work if the ignition system has enough  energy available. Not all will.   Best general rule of thumb is to start with what is called for and then experiment from there. As many have noted there is some leeway as to how much resistance some systems can handle.   Just be careful if you change the heat range towards hotter as that can cause the most damage.

[izzuG]

I ordered 6 plugs (BP6ES/NGK 4007) from my local NAPA Tuesday, they arrived today. They can't get them from suppliers, but many stores have them in stock. Mine shipped to MA from Buffalo.

[centauro]

I switched over to Nippon Denso plugs because of NGK stopped making the BP6ES non resister plug.

I can say that the ND plugs offer in my case a better running bike so give then a try

NGK BP6ES equals the Nippon Denso W20EP-U Both are non-resister

side note ---I'm using the 5 ohm Bosch resister caps, no issues , if you need resister caps NGK still makes them

TOMB

+1. I won't shed any tears on NGK BP6ES plugs no longer available. Contrary to most other people, the only plugs that ever failed me were those.
Not Champion, not ND, not AC, not Bosch. But my favorite is still the Nippon Denso brand.