Britbike forum
Posted By: Ragmanx Champion N3 or N4 ? - 01/02/21 8:03 pm
Which plug would you prefer for my '68 Lightning ?
Thank you
SteveG
Posted By: raf940 Re: Champion N3 or N4 ? - 01/02/21 8:14 pm
i use champion N4G in mine
Posted By: Irish Swede Re: Champion N3 or N4 ? - 01/02/21 9:24 pm
Weren't Champ N4 plugs directly specified for BSA A65s? ?
Posted By: Shane in Oz Re: Champion N3 or N4 ? - 01/02/21 10:27 pm
N3 was standard, but N4 works fine as well for normal riding.
Posted By: raf940 Re: Champion N3 or N4 ? - 01/02/21 10:29 pm
i ride 'moderate' speeds use the N4Gs in all my bikes they work great the N3s were too cold...but that's just my experience
Posted By: Phil in Germany Re: Champion N3 or N4 ? - 01/02/21 10:29 pm
If I recall correctly, BSA had specified Champion N3 for the Lightning, N4 for the Thunderbolt.

I run Champions N3C in my Lightning and the Firebird, the plugs are absolutely fine and troublefree.

There is a chance that Federal Mogul has changed or will change the type designation for the plugs, I have read the N3C would be listed as Champion 801C in the future. Slightly confusing but no worrisome.

HTH

Cheers!

Phil
Posted By: raf940 Re: Champion N3 or N4 ? - 01/02/21 10:38 pm
should have said my 68 A65 bitsa is single carb....
Posted By: Ragmanx Re: Champion N3 or N4 ? - 01/03/21 12:46 am
Thanx for all the replies.
My bike, with C3's, was getting hard to start in the cold. Removed and cleaned the plugs. Replaced them and it started right up with help from the choke.

I ordered two C4's from WallyWorld for $9 including shipping to try them out.

The BSA work Shop Manual calls for C4 plugs.

So all is well and you guys opinions backed that up.

Thanx again
SteveG
Posted By: htown Re: Champion N3 or N4 ? - 01/03/21 3:09 am
Factory manual says NC3 for Lightening, NC4 for Thunderbolt. Which is a bit strange because the engines at least in the late sixties bikes were identical except for the carbs and the tach drive. Maybe they figured the Thunderbolt was the sedate tourer and need a slightly hotter plug. Probably either will work in either bike except maybe a preference for the 3 when doing a lot of higher speed riding in hot weather.
Posted By: Ragmanx Re: Champion N3 or N4 ? - 01/03/21 6:21 am
Thanx for your reply.

The work shop manual that I have says Champion N4 for the A65 Lightening. Page GD 11.

From all the responses I read, I think the are very comparable. Probably depends on the owner and their particular bike.

I will run theC3's (now cleaned) and try the C4's when they arrive.

SteveG
Posted By: Ola Re: Champion N3 or N4 ? - 01/03/21 9:41 am
Many plugs will fit the A65. The question is, what plug will fit the rider?

Regards
Posted By: John Healy Re: Champion N3 or N4 ? - 01/03/21 5:59 pm
There is much confusion when it comes to plugs. A change in grade of spark plug can be required because of changes made to the engine. Raising or lowering compression is one such example. But change the factory recommended plug because a plug fouls either from fuel or oil is not a wise decision. This especially true if the fouling is fuel related.

Take a Mikuni VM or one of the amal series carburetors. There is one throttle position we use the most. That is between 1/8 and 1/3 throttle. This is where the straight portion of the needle sits in the needle jet's orifice. Because the the needle moves back and forth, sliding on the brass jet, with each change in air flow as the piston draws air into the cylinder. This cause the inside diameter of the jet to enlarge over time. This leads to a rich condition in only a narrow part of the power band. The one most of us use the most: the point where the straight portion of the needle is in the needle jets orifice.

This incidental enrichment can cause the factory recommended spark plug to foul. This is happening not because you are using the wrong plug, but because the real fault is not being addressed.

Why is this important? When you changed the grade of the plug to cure the rich condition at low throttle openings the jetting when the taper takes progresively returns to normal with no change from factory jeting as the slide approaches 3/4 throttle.

So the first time you open the throttle above 1/3 throttle without the bike increasing speed (this is what is called lugging) your hotter plug that was a cure for low speed fouling now becomes a problem. It puts you one step closer to destructive detonation and detonation induced pre-igntion.

Oil fouling can create the same problem. Oil or fuel fouling is not a problem to be solved by changing plug grades! If the factory recommended plug doesn't work, and you foul plugs (either fuel or oil) it is not the plug's problem.

I see another post where someone wants to use a hotter grade plug because it has got cold and he has to use the choke. This is not a plug problem! In a properly jetted engine it is normal to have to choke the carburetor to get the engine running.
Posted By: Ragmanx Re: Champion N3 or N4 ? - 01/03/21 8:26 pm
Thanks for your good insights.

I suspect I maybe be the cause of my problem by tickling the carbs too much, thinking that the engine was being starved of fuel.
Thereby fouling the plugs.

I say this because after I cleaned the plugs, the bike fired right up.

The weather here is pretty bad and I cannot ride enough to really make any meaningful determinations.

The plan , weather permitting, is too continue with the C3's. The book calls for C4's and I have some coming. Then will go from there.

Thank you,
SteveG
Posted By: Allan G Re: Champion N3 or N4 ? - 01/03/21 10:36 pm
It’s already been mentioned but Lightning’s and other more sporting twin carb variants got N3’s and touring bikes for N4’s.

I’ve found that both bikes are happy on N3’s. I’ve ran my lightning on N4’s.... but it does seem happier on N3’s
Posted By: Ragmanx Re: Champion N3 or N4 ? - 01/04/21 1:45 am
All good insights.

I'm getting conflicting info. Which plug is hotter?
Posted By: John Healy Re: Champion N3 or N4 ? - 01/04/21 2:40 am
N4 is hotter than an N3.
Posted By: Ragmanx Re: Champion N3 or N4 ? - 01/04/21 7:07 am
Thank you.
Posted By: Mark Z Re: Champion N3 or N4 ? - 01/04/21 2:18 pm
Another thing that was not mentioned is the change in fuels over the years. These days the rims of the plugs are always black even if the porcelains are light tan to white. As I recall, in the "old days", I could achieve a tan color all over the plugs.

I have always run the highest octane fuel I can get at the pump, which today is 93.
Posted By: Allan G Re: Champion N3 or N4 ? - 01/04/21 2:49 pm
That sounds like a rich idle mixture or high float level Mark if you have dark rings on the plugs. If you remove a plug from a car with fuel injection then the whole plug metal area will be a nice tan colour.
Posted By: John Healy Re: Champion N3 or N4 ? - 01/04/21 5:02 pm
Quote
I have always run the highest octane fuel I can get at the pump, which today is 93.

That 93 number on the pump is not the fuel's octane rating!!It is the anti-knock-index. A US fuel with a 93 AKI will have a RON (research octane number) of 98.

Using RON as a target, which is the number we used in the US for decades, the highest pump gasoline you can get is 98 RON (plus or minus a bit).
Posted By: DavidP Re: Champion N3 or N4 ? - 01/05/21 6:03 am
From my experience reading plugs is nothing but confusion.
When I installed new Premiers on my Trident I immediately went out for a ride, holding the throttle at a constant opening I got plugs which looked perfect, ashen colored with a good color ring when viewed through an otoscope. Tuned the idle mixture using the Color Tune. Ever since the plugs come out black.
FWIW I use N4's in my A65. The deposits start just at the bend in the electrode.
Posted By: NickL Re: Champion N3 or N4 ? - 01/05/21 11:00 pm
These days it's better to see some colour on the plug, err on the safe side
unless you can guarantee the fuel you buy is good. The poofteenth of power
lost is worth not holing pistons.
Posted By: Allan G Re: Champion N3 or N4 ? - 01/05/21 11:43 pm
Originally Posted by NickL
These days it's better to see some colour on the plug, err on the safe side
unless you can guarantee the fuel you buy is good. The poofteenth of power
lost is worth not holing pistons.

More likely to see some colour with the right mixture on the right plug than a suspect or right mixture on a hotter plug.. and you minimise the risk of holing pistons.
Posted By: kevin Re: Champion N3 or N4 ? - 01/06/21 12:02 am
my go-to plug for most purposes has always been the NGKB8ES. but its been discontinued. i thought about spending a bunch of money for some to use up, but unless i spend several hundred bucks on those and a lot of B9s i'll have to get an alternative pretty quick anyway.

i suppose i'll go back and see whether the champions will work for me this time around. i gave up on em years ago but maybe it was just me.

in the meantime i don't know what to do about the magneto machines, as the NGK replacements for the B8ES and B9ES aren't reccommended for magnetos.
Posted By: BSA_WM20 Re: Champion N3 or N4 ? - 01/06/21 9:34 am
Originally Posted by kevin
my go-to plug for most purposes has always been the NGKB8ES. but its been discontinued. i thought about spending a bunch of money for some to use up, but unless i spend several hundred bucks on those and a lot of B9s i'll have to get an alternative pretty quick anyway.

i suppose i'll go back and see whether the champions will work for me this time around. i gave up on em years ago but maybe it was just me.

in the meantime i don't know what to do about the magneto machines, as the NGK replacements for the B8ES and B9ES aren't reccommended for magnetos.

I think you willfind it has been replaced with the BP8ES
Most standard plugs are being replaced with the projecting electrode type "P" .
Unless you are running bigger pistons than 10:1's or have shaved the head past its functional limit they should clear the pistons.
Posted By: Allan G Re: Champion N3 or N4 ? - 01/06/21 11:23 am
Originally Posted by BSA_WM20
Originally Posted by kevin
my go-to plug for most purposes has always been the NGKB8ES. but its been discontinued. i thought about spending a bunch of money for some to use up, but unless i spend several hundred bucks on those and a lot of B9s i'll have to get an alternative pretty quick anyway.

i suppose i'll go back and see whether the champions will work for me this time around. i gave up on em years ago but maybe it was just me.

in the meantime i don't know what to do about the magneto machines, as the NGK replacements for the B8ES and B9ES aren't reccommended for magnetos.

I think you willfind it has been replaced with the BP8ES
Most standard plugs are being replaced with the projecting electrode type "P" .
Unless you are running bigger pistons than 10:1's or have shaved the head past its functional limit they should clear the pistons.

Im glad you brought up projected plugs Trev'. I was reading a bunch of service sheets the other night. I noticed that for the humble D14 Bantam is instructs to change the plug from the standard N4 to the N9Y which is projected electrode. And to use a thicker (0.050") head gasket or two standard head gaskets (0.025" thick).

Im assuming that this is a major change in heat range, but what also would the gain from the projected tip plug? having worked and owned these bikes and always used the N4 as that is what is shown in the manual, I am quite curious.
Posted By: kevin Re: Champion N3 or N4 ? - 01/06/21 11:44 am
Originally Posted by BSA_WM20
Originally Posted by kevin
my go-to plug for most purposes has always been the NGKB8ES. but its been discontinued. i thought about spending a bunch of money for some to use up, but unless i spend several hundred bucks on those and a lot of B9s i'll have to get an alternative pretty quick anyway.

i suppose i'll go back and see whether the champions will work for me this time around. i gave up on em years ago but maybe it was just me.

in the meantime i don't know what to do about the magneto machines, as the NGK replacements for the B8ES and B9ES aren't reccommended for magnetos.

I think you willfind it has been replaced with the BP8ES
Most standard plugs are being replaced with the projecting electrode type "P" .
Unless you are running bigger pistons than 10:1's or have shaved the head past its functional limit they should clear the pistons.

we ll see. i run B9s in a machine with 11.75 to 1 pistons, but the B8s go into an ordinary 9.5 to 1.

i dont think the BP plugs are appropriate for magnetos but i cant find the original email fro m dan at franz and grubb that described the discontinuation
Posted By: bodine031 Re: Champion N3 or N4 ? - 01/06/21 12:07 pm
Champions made in Mexico are of poor quality,caution.
Posted By: BrizzoBrit Re: Champion N3 or N4 ? - 01/06/21 12:27 pm
I went to NGK website. Both the B series and and the BP (projected) series are being replaced with BR and BPR respectively. The 'R' signifies internal resistor. NGK specifies internal resistance to change from 1k ohm to 5k ohm with this changeover. That increase in resistance not good for magnetos as I understand it. Like adding resistor caps. So if running resistor caps and resistor plugs you will now have 10k ohm to overcome. I've found it hard, but not impossible, to find non-resistor caps (I typically use the NGK ones)

While digressing a bit now that we are onto NGK this has been useful as I have run B7ES/BP7ES forever in my A65 and I'll now try the 8's as that seems reasonable based on the comments here. Ironically, I bought a few years supply of BP7ES earlier today in response to learning that they were being discontinued. I should have read and digested this thread a bit better before doing that. I tried Champions (N3C/N4C) when first sorting out the bike but could somehow never seem to settle on them for some reason. Should give them a whirl again now that I have the bike carburetion and timing more sorted than it was when first built. I do get 2 or 3 threads of black with the BP7ES which I thought was the indicator of correct heat range?

Allan, my understanding is that the spark gap projects further into the air/fuel mix for better ignition. IIRC I also saw somewhere that plug nose of a projected tip plug is cooled better by the incoming air/fuel charge which might explain the use of a '9' for the projected tip plug?

Cheers
ray
Posted By: NickL Re: Champion N3 or N4 ? - 01/07/21 12:35 am
B8EV's are still around if you don't want resistor plugs, that's what i've used for ages.
Mainly because i had 'em left over from racing. The narrow electrode is a plus.
Posted By: BSA_WM20 Re: Champion N3 or N4 ? - 01/07/21 12:37 am
What people tend to overlook is NGK's have a narrower heat range than Champions so the difference between B7's & B8's is nothing like the difference between an N3 & N4
I run B5 to B8 in the M20 depending upon how far I am riding, how many stops & temperatures .
Winter short club rides need much hoter plugs than a 450 Km ride to the ABR .
Posted By: BSA_WM20 Re: Champion N3 or N4 ? - 01/07/21 12:42 am
Originally Posted by Allan G
Im glad you brought up projected plugs Trev'. I was reading a bunch of service sheets the other night. I noticed that for the humble D14 Bantam is instructs to change the plug from the standard N4 to the N9Y which is projected electrode. And to use a thicker (0.050") head gasket or two standard head gaskets (0.025" thick).

Im assuming that this is a major change in heat range, but what also would the gain from the projected tip plug? having worked and owned these bikes and always used the N4 as that is what is shown in the manual, I am quite curious.

Projected tips stick out further which makes igniting the charge easier and fouling of the plug harder.
IT does not change the heat range so why the recommendation to go way hotter I have no idea.
Posted By: NickL Re: Champion N3 or N4 ? - 01/07/21 1:09 am
Much of the plug fouling stuff is due to mag or ignition system condition.
That is of course if the engine has rings and guides that seal reasonably well.
Most of these old crates will run on a lighted newspaper in the plug hole.
Posted By: Allan G Re: Champion N3 or N4 ? - 01/07/21 7:58 am
Originally Posted by NickL
B8EG's are still around if you don't want resistor plugs, that's what i've used for ages.
Mainly because i had 'em left over from racing. The narrow electrode is a plus.


I’ve ran these, I think ts platinum or palladium? Electrode. Found they were great especially when running with rich carb jettings, they could be sooted to the eye balls and still run fine. ( I was trying to get the carbs dialled in to my new exhaust system at the time)
Posted By: NickL Re: Champion N3 or N4 ? - 01/07/21 10:48 pm
Allan, i meant B8Ev's or B7EV''s i corrected the post.


The EGV's are very expensive but are very good.
Either type is the narrow electrode racing plug type and are
resistant to fouling.
Posted By: BSA_WM20 Re: Champion N3 or N4 ? - 01/08/21 2:19 am
Originally Posted by bodine031
Champions made in Mexico are of poor quality,caution.

How many spark plug factories do you think there are ?
I worked for a short while on the night shift at the Champion plug factory in Sydney.
We made every brand of plug the was currently available at the time.
Other manjor brands were packed into 144 plug racks & sent elsewhere to have the name & grade printed on them.

You will probably find the Mexico plant makes 3/4 of the standard plugs avalable in the USA and th other 1/4 is imported from China becuse there is no profit in making a std spark plug.
The brand name factories will be making the highly profitable exotic metals plugs & outsourcing the std ones.
Posted By: Irish Swede Re: Champion N3 or N4 ? - 01/08/21 12:50 pm
Thanks, WM20.

Very enlightening information, sure to "spark" some controversy.
Posted By: kevin Re: Champion N3 or N4 ? - 01/09/21 12:14 am
in america beer is often brewed generically

mainstream brands sometimes differ only in the labels.
Posted By: Mark Z Re: Champion N3 or N4 ? - 01/09/21 3:04 am
Originally Posted by kevin
in america beer is often brewed generically

mainstream brands sometimes differ only in the labels.

Even Yuengling? Say it ain't so!
Posted By: Irish Swede Re: Champion N3 or N4 ? - 01/09/21 11:28 pm
We can't buy Yuengling here in the mid-west, nut I was given some by friends from New Yourk and Pennsylvania at a meet in Ohio, and I can say
Yuengling is DAMNED GOOD BEER!
Posted By: BSA_WM20 Re: Champion N3 or N4 ? - 01/10/21 4:37 am
The last contract I had , one of the products we delivered was "imported Asian beers "
There were 5 "different" beers from 4 "different" countries.
All brewed locally and the different labes were applied by the picking staff.
They tasted different because they were all served at different temperatures which apparently is how it is drunk locally.

Way bak when I had long hair and a full mouth of teeth I worked at the top hotel in Sydney
In those days it was one of only 2 Five star ones.
One station I did was functions
We used to use individual waiters to dispense differnt spirits
So for the first 1/2 hour to hour what was in the bottles was what was on the label .
However for the rest of the night the bortles were filled with cheaper spirits
Probably dispensed near a million drinks, never had a single person question what they were drinking.
All they ever worried about was getting a "good" full nip
Posted By: S-NJ-W Re: Champion N3 or N4 ? - 01/10/21 2:15 pm
Originally Posted by kevin
in america beer is often brewed generically

mainstream brands sometimes differ only in the labels.

As we are off topic (can discussion of beer EVER be off topic?)

Heresy :

Fans of Newcastle Brown Ale will notice a new flavor. That's because production has moved from the Netherlands to the U.S., where Chicago's Lagunitas Brewery will now make the beer under a new recipe. Both brands are owned by Heineken, which made the switch as part of the U.S. relaunch of Newcastle Brown Ale.
Posted By: Hugh Jörgen Re: Champion N3 or N4 ? - 01/10/21 2:30 pm
Newcastle Brown
I'm tellin' ya can sure smack you down
Posted By: Ragmanx Re: Champion N3 or N4 ? - 01/12/21 4:30 am
I'm so confused -

Should I use a Yuengling or an N4 in my '68 A65L?

Thank you,
SteveG
Posted By: Shane in Oz Re: Champion N3 or N4 ? - 01/12/21 6:42 am
After a couple of pints of Newkie Broon, ye won't care
Posted By: Allan G Re: Champion N3 or N4 ? - 01/12/21 7:38 am
Originally Posted by Ragmanx
I'm so confused -

Should I use a Yuengling or an N4 in my '68 A65L?

Thank you,
SteveG

An N3
Posted By: BrizzoBrit Re: Champion N3 or N4 ? - 01/12/21 12:31 pm
Now, back on track folks......despite the valuable alternatives discussed. But I can tell you XXXX is so sh*t it couldnt be masquerading as anything else.


Nick, sorry to disappoint you mate, but even the exotic electrode plugs have been superceded with resistor versions. WTF is the world coming to? shocked
Good thing you have a stock of those smile.

https://www.ngk.com/ngk-6724-b7ev-gold-palladium-spark-plug

The EGVs supercede to this plug as well.


I discovered this a year or 2 ago when I ordered B9EGVs (as advertised) from an online seller so I could get a stock of these and got sent the BR9EIX resistor supercession items. When I sent them back the response was "they're the same, just the superceded items". Then ensued an unwanted lesson on spark plugs for the poor young kid on the other end of the email.

Trev, good point about the heat ranges. You are sharpening up my dull brain.


R
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