spark plugs

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The second link you sent is very good. I goes well with what I have learned.

Keep in mind with an air cooled motor -if the plug is too hot for the tune of the engine then you will get pre-ignition under load for only a few seconds- then will come detonation [the death rattle] and it will only last for 3 to 5 seconds before failure. Done it more than a few times. Jim
 
Check this one out! I'm on look out for spark enough to burn water. This is in air so may not work as advertised for me.
[video]http://www.youtube.com/watch?v=1P5ySD4SoIY&feature=fvw[/video]
 
Chart brand heat chart
http://www.clubplug.net/cross.html

Nomenclature:
Consulted my NGK Guide 1982-83

Example BP6ES 14mm, projected tip, medium heat rating, 3/4" reach, super
wide range

First letter = Diameter of thread
A 18mm
B 14mm
C 10mm
D 12mm

Second letter (if it exists)
P Projected Tip


Third letter (if it exists)
R Resistor type

Number = Heat Rating
Small number Hot
Large number Cold

Next letter = Reach
E 19mm 3/4"
H 12.7 mm 1/2"
A 19mm 0/471"
B 9.8mm 3/8"

Next letter (if it exists)
S Super wide range


The 'Super' has a copper core with nickel tip, so the catalogue says.
It goes on to talk of Racing types eg B-9EP where the last letter could be;
N Nickel electrode
P Platinum electrode
V 'V' type grooved centre electrode
G 'G' type (doesn't elaborate)

There are also some special plugs mentioned,
Surface discharge type eg BUHW
Shielded type eg BS-4E
Projected Gap type eg BRE527Y-11
Farm type eg G-2Z

Cheers

Dennis Wright
The Repro Lucas Magneto Tag Guy
1961 Triumph T120R Bonneville
1965 Honda C78 Dream
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In tradition of never ending hobby lessons - keep reading deeper.

Real Spark Plug Reading:
For plug reading, You need to cut the metal off the insulator and look at the BASE OF THE PORCELAIN. When it's right you'll see a "wedding ring" looking black ring at the base of the porcelain, and from there all the way up should be white.
Forget the metal part of the plug, look at the ceramic if you want to try to get A/F right by plug reading. A wideband is THE way to go, it won't just tell you what your mixture was when you turned it off like plug reading does.
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spark plugs


Good pictures of disected plugs:
http://www.dragstuff.com/techarticles/p ... tures.html

One thing that people might not know is that unleaded pump gas colors the plug very little if at all when the mxiture is right. The way to read a plug is to install a new plug, go and do an extended top end run and do what is called a plug chop, kill the ignition while at WOT and coast to a stop.

These tips are for unleaded pump gas only, leaded race fuel will color the plugs traditionaly, shoot for tan to brown. Octane booster may color the plugs strangely like orange or even green.

Pull the plug and look at the center electrode porcelein. On pump gas the electrode insulator will be a very light tan/greywhite. If you look down into the crevice between the center electrode insulator and the plug shell, you will see a grey/black ring of color. If you don't see one, chances are you are too lean.

Look for tiny fleck that look like pepper on the center electrode insulator, if you see that, that is a sign of detonation and leaness

Look at the metal center electrode and the ground electrode. They should be clean but not show signs of bluing or worse yet tiny dingle balls that look like mini weld splatter. That is a sign of detonation and over leaness.

To determine pilot jet size, wing the throttle and feel the response in the first 1/3 of the throttle opening, then drive through this region while moving the throttle open very slowly. Too rich will feel sluggish with a burbly exhaust note with the engine slow to respond to throttle input. Too lean will surge, the engine will stutter and be hard to hold at a stready speed.

On this forum, it seems like people mix up the feel for a bog, surge and flatspot, thus too lean and too rich are confused. Hopefuly this description will help clear that up. Do A to B testing and only change one thing at a time.

Generaly if a plug looks brown or black on unleaded pump gas, then its way too rich. It is also hard to hear detonation on small bore motors with shallow included valve angles like ours so you gotta feel careful.

The best way to observe your jettings effectiveness (the main circuit)without a dyno or wideband is to measure time to speed or RPM to distance. You can easily devise some common sence tricks for that.
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Mike,
I was rubbing an old commando oil tank in the garage and out popped Vivian Neeves :shock: , so I took a picture of her on my bike
for old time sake before I put her back in the tank. "I dream of Vivian" , hey maybe a new rendition on and old movie theme :mrgreen:
Ok back to reality :cry:
Jim, thanks for the heat range run down on the plugs.I will watch them and if they are causing a lean condition I'll go with AP63's.
The 64's the way I read the chart are like BP6es, I'm not running APP series? They do show BP5es range. Not sure what they are for?
I don't race this thing so overheating as in track conditions should and I say should not be an imminent danger on the street.
Besides it's getting so crowed here in Penna I can barely get into 4th gear unless I get to the country and find a back twisty.
Yeah Baby that's what a Norton is all about :wink:
Happy Thanksgiving to all!!!!!!!!!!!!
Thee Marshal.
 
Nice photoshop work Marshall, Same here as far as traffic goes. Took the Norton out yesterday and rode up to Malibu along the coast, The traffic was fairly heavy all the way from Redondo beach on up. If not for the weather and the girls it would have been a real bummer. As far as plugs go I have always used the BP7ES NGK, They seem to last and I have never had a plug problem. Ride safe guys.
 
Well it was 2004 when I did the testing and posted on it at that time here's a copy of that post:

by norbsa48503 » Wed Aug 18, 2004 6:38 am
Plugs are fun I have been playing with mine and have found them to be useful once your close on the carbs. In third gear wind outs trying to get the bike to red line. Bosch Plat. WRP 7 100 mph than Auto lite AP63's 105 mph then AP 64 110 mph at 6500 rpm with my fat 240lb straight up in the wind. Now check to make sure that long runs on the x-way in fourth at 80mph and 4250rpm don't run too hot. They seem fine on my bike. So run as hot as you can sustain on the x-way at constant speed because that helps the most with all the other riding. I tried the Bosch plat fours they were great down low really smooth but were breaking up under high rpm's were life is exciting. norbsa


Well its 2010 the bike is still running just fine, same set up. I posted the Drag stuff links way back in 2004 as well but we still have posts about nice tan plugs here in 2010 so rather then beat my head against the wall… I just show the Jennings link it takes about 200 miles to get them looking like #19. Your bike could end up not tolerating my set up I run mark two carbs 1 5/8 exhaust and have 1500.00 into head work and run aluminum jugs oh the horror so cover you own ass read your own plugs. I don't want to blow up your bike.
My point is that it depends heavily on how you use your bike as to how your plugs read and run. I run to red line at least once on every ride so don’t follow my ramblings I don’t think many of us do that so adjust my findings up against yours. It seems I am at some extreme that makes others find difficult to tolerate oh well. I have pulled some motor down with an 1/8 of carbon coating on the pistons and had the owner tell me it ran fine until the valve stuck. My pistons just keep a wisp of black, about like the ring around the plugs. So use me as the crazy end of the scale.
 
I tried out a set of APP64's today. I did it because I'm using a Boyer Micropower CDI ignition. They are a suppressor plug, so it seemed like a nice match. The spark is bigger to look at and it starts on the first kick. With WR7DP's it was a 1-3 kick starter. The motor is a stock 850 with a VM34. 35 pilot, 3.0 slide, P-4, 6DH3 needle middle, 250 main. The timing is set at 30deg, not verified with a wheel though. The Auotlite site lists the AP64 as a crossover for the WR7DP.
http://www.autolitecatalog.com/Competit ... dp&em=True
This is what the plugs look like after about a 30mi ride today. Puttering at the beginning and end with some WOT in the middle of the ride. It felt strong and maybe better sorted.

spark plugs


I can't shoot macro for beans but there is a dusting of tiny silver spheres. I'm thinking that there is some detonation going on. Either the plug is too hot or my timing isn't really 30deg, or both. I don't have a WR7DP nearby to upload a picture but they never had any silver specks and they were generally darker everywhere. The porcelain was dark on one half, light on the other. I think that maybe Autolite is a little loose with their crossover chart.
Maybe I'll try an APP63, and dig out the degree wheel.
 
bpatton said:
I tried out a set of APP64's today. I did it because I'm using a Boyer Micropower CDI ignition. They are a suppressor plug, so it seemed like a nice match. The spark is bigger to look at and it starts on the first kick. With WR7DP's it was a 1-3 kick starter. The motor is a stock 850 with a VM34. 35 pilot, 3.0 slide, P-4, 6DH3 needle middle, 250 main. The timing is set at 30deg, not verified with a wheel though. The Auotlite site lists the AP64 as a crossover for the WR7DP.
http://www.autolitecatalog.com/Competit ... dp&em=True
This is what the plugs look like after about a 30mi ride today. Puttering at the beginning and end with some WOT in the middle of the ride. It felt strong and maybe better sorted.

spark plugs


I can't shoot macro for beans but there is a dusting of tiny silver spheres. I'm thinking that there is some detonation going on. Either the plug is too hot or my timing isn't really 30deg, or both. I don't have a WR7DP nearby to upload a picture but they never had any silver specks and they were generally darker everywhere. The porcelain was dark on one half, light on the other. I think that maybe Autolite is a little loose with their crossover chart.
Maybe I'll try an APP63, and dig out the degree wheel.
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You are on the verge of destruction. The little silver balls are aluminum from the top of the piston. You better go at least a couple heat ranges colder. Jim
 
Don't look into the eyes of the Sun, but mama that's where the fun IS!

Going by the thermal stain on the hook, I'd say you've now got such a fast burn the timing is slightly advanced so might back off to Combat specs 28" total or so.
Might bump up richness of course and it might like that to avoid detonation evidence. What octane is being used? Any booze in it? You may just need to shift max pressure a bit further on crank rotation ~11' ATDC to flat out run the thermal spike by sucking its mechanical power out just then.
 
Re: Photo shop

I can't take credit for photo shop job.
It was done for me and PM'd to me by a forum member.I'm publicly appoligizing as I forget who the artist was. :oops:
Who ever it was you may take credit for your work 8)
I thought I'd have a little fun with it no sense hiding it in a pics file.
The silver ball thingy with BPattons plugs has me thinkin I better pull my AP64's and look.
I did 78 miles w/ em so far.
Some have had no problems but Jim did caution us so I will look before I do any damge.
I may try the AP63's and if I do not get any negative results I'll try em for a season.
Good thread.
It's all good fun until someone get's hurt or f...k..up.
Live vicariously through others foolishness I say.
Thee Marshal
 
A plug that fires at lower voltages, like a suppressor plug, fires in advance of normal timing, just like increasing the gap results in retarded firing. Using suppressor plugs in a Norton is inviting detonation.
 
Rick,
thanks for the explanation.
I may have time next Tuesday to pull plugs and take a looksy.
Don't think one can do damage in 78 miles but any concerns I'm going to go cooler.
8) Marshal
 
Re: Photo shop

MarshalNorton said:
It's all good fun until someone get's hurt or f...k..up.
Live vicariously through others foolishness I say.
Thee Marshal
Click to expand...

One tries to be of service :D

rick in seattle said:
A plug that fires at lower voltages, like a suppressor plug, fires in advance of normal timing, just like increasing the gap results in retarded firing. Using suppressor plugs in a Norton is inviting detonation.
Click to expand...

If I strobe the timing with the suppressor plugs will it show up? I'll check tomorrow with a set of AP63's.
 
Yes it would show but it is likely to be a very small change. Maybe a degree. Jim
 
Each plug type will have its own best timing range and gap depending on the type of coil charge sparking it. Best power may need more gap or less gap depending on fuel and Compression. A decent ignition is going to fire the plug when it triggers the coil to do so regardless of the gap. Adjust timing so the spark can burn most fuel before any of the piston. Data implies ~.010" narrower gap for HI CR and HI rpm. Good cruise part throttle efficiency generally likes ~.010 wider gap.
 
Bob,
my good man that quote was not directed to any one person(s)
I just like that quote.
Apology due if anyone was offended :oops:
I too may revert to AP63's I'll pull my plugs Tuesday and report.
Your AP 64 review along with Jim's caution notes have been very help full
and certainly taken under advisement.
Marshal
 
wow 6 pages on a sparkplug thread - the weather must really be bad in most parts of the world or we'd all be out on our bikes......
 
I used the NGK 89ES for the longest time but due to my apparent non-skill in tuning the carburators properly I had to clean the plugs every 200 miles of riding (way too rich)
A friend told me he had good success with the BOSCH platinum spark plugs. I installed them at the beginning of this riding season and they are still working great after 4000 + miles without ever taking them out for cleaning.

Cheers,
Josh in Calgary
 
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