It seems to me that all the screws and bolts on my Japanese motorcycle
are metric, except the sparkplugs.

AFAICT, neither the threads nor the socket required for the sparkplugs
used in my Honda are metric. Is that so, and how did it happen?

If you are inclined to email me
for some reason, remove NOPSAM :-)

mm wrote:
It seems to me that all the screws and bolts on my Japanese motorcycle
are metric, except the sparkplugs.

AFAICT, neither the threads nor the socket required for the sparkplugs
used in my Honda are metric. Is that so, and how did it happen?


Huh? I though ALL sparkplugs were metric - a residual from the days (~1900)
when the ONLY sparkplugs a U.S. engine maker could get came from Europe.

Are you saying we are slowly converting Asia to the Imperial System?

On Fri, 17 Nov 2006 08:02:47 -0600, "HeyBub"
wrote:

mm wrote:
It seems to me that all the screws and bolts on my Japanese motorcycle
are metric, except the sparkplugs.

AFAICT, neither the threads nor the socket required for the sparkplugs
used in my Honda are metric. Is that so, and how did it happen?


Huh? I though ALL sparkplugs were metric - a residual from the days (~1900)

Well maybe the threads *are* all metric. I wanted to get a nut that
would go on a sparkplug, to make a spark tester, and none of the
English nuts fit. OTOH, I tried all the metric nuts and none of them
fit either. OT3H, they didn't have nuts in all possible metric sizes.
I think HD skipped from 12mm straight to 15mm, so maybe 14 would fit.

when the ONLY sparkplugs a U.S. engine maker could get came from Europe.

But even if the threads are metric, don't spark plug sockets come in
13/16 for the big ones, and other English sizes for the smaller ones?

Somewhere I have a set of metric sockets complete with extensions and
spark plug socket, and I've been looking for them ever since I got my
motorcycle. CAn't find them, so I don't know how the spark plug
socket is labeled. (I've been using a bunch of metric sockets
gathered from junk boxes along the way.)

Are you saying we are slowly converting Asia to the Imperial System?

Yes, that's why GWBush is in Viet Nam. He's promoting the inch, the
foot, the pound, and most of all, the caliber.



If you are inclined to email me
for some reason, remove NOPSAM :-)

"mm" wrote in message
news
On Fri, 17 Nov 2006 08:02:47 -0600, "HeyBub"
wrote:

mm wrote:
It seems to me that all the screws and bolts on my Japanese motorcycle
are metric, except the sparkplugs.

AFAICT, neither the threads nor the socket required for the sparkplugs
used in my Honda are metric. Is that so, and how did it happen?


Huh? I though ALL sparkplugs were metric - a residual from the days
(~1900)

Well maybe the threads *are* all metric. I wanted to get a nut that
would go on a sparkplug, to make a spark tester, and none of the
English nuts fit. OTOH, I tried all the metric nuts and none of them
fit either.

Get a spark plug heli-coil thread repair kit then drill, tap and thread
insert whatever you want to.

"mm" wrote in message
news
It seems to me that all the screws and bolts on my Japanese motorcycle
are metric, except the sparkplugs.

AFAICT, neither the threads nor the socket required for the sparkplugs
used in my Honda are metric. Is that so, and how did it happen?



I don't know about the newer cars, but about 20 years ago when I was going
to change the plugs in my first Datsun I stopped in the local Advance Or
Autozone store to get some plugs and a socket. I had a good collection of
American tools but nothing metric at the time. Told the guy in the store I
needed a socket for the plugs and thought it would be metric. He did not
know. We took some metric wrenches and matched them to the plug. They did
not fit,but when I put one inthe American wrenches, they did. Turned out I
had the plug socket for them all the time. Talked with a mechanic later
and he told me at that time all the plugs he changed were the American type.
I don't remember about the threads.

mm wrote:
On Fri, 17 Nov 2006 08:02:47 -0600, "HeyBub"
wrote:

mm wrote:
It seems to me that all the screws and bolts on my Japanese motorcycle
are metric, except the sparkplugs.

AFAICT, neither the threads nor the socket required for the sparkplugs
used in my Honda are metric. Is that so, and how did it happen?


Huh? I though ALL sparkplugs were metric - a residual from the days (~1900)

Well maybe the threads *are* all metric. I wanted to get a nut that
would go on a sparkplug, to make a spark tester, and none of the
English nuts fit. OTOH, I tried all the metric nuts and none of them
fit either. OT3H, they didn't have nuts in all possible metric sizes.
I think HD skipped from 12mm straight to 15mm, so maybe 14 would fit.

I believe almost all sparkplugs are either 14mm or 18mm thread.


when the ONLY sparkplugs a U.S. engine maker could get came from Europe.

But even if the threads are metric, don't spark plug sockets come in
13/16 for the big ones, and other English sizes for the smaller ones?

13/16 or 5/8. But I believe that the actual size of the hexes is the
next smallest mm size; they're just close enough to make no never mind.

nate


Somewhere I have a set of metric sockets complete with extensions and
spark plug socket, and I've been looking for them ever since I got my
motorcycle. CAn't find them, so I don't know how the spark plug
socket is labeled. (I've been using a bunch of metric sockets
gathered from junk boxes along the way.)

Are you saying we are slowly converting Asia to the Imperial System?

Yes, that's why GWBush is in Viet Nam. He's promoting the inch, the
foot, the pound, and most of all, the caliber.



If you are inclined to email me
for some reason, remove NOPSAM :-)

"N8N" wrote in message
oups.com...

mm wrote:
On Fri, 17 Nov 2006 08:02:47 -0600, "HeyBub"
wrote:

mm wrote:
It seems to me that all the screws and bolts on my Japanese motorcycle
are metric, except the sparkplugs.

AFAICT, neither the threads nor the socket required for the sparkplugs
used in my Honda are metric. Is that so, and how did it happen?


Huh? I though ALL sparkplugs were metric - a residual from the days
(~1900)

Well maybe the threads *are* all metric. I wanted to get a nut that
would go on a sparkplug, to make a spark tester, and none of the
English nuts fit. OTOH, I tried all the metric nuts and none of them
fit either. OT3H, they didn't have nuts in all possible metric sizes.
I think HD skipped from 12mm straight to 15mm, so maybe 14 would fit.

I believe almost all sparkplugs are either 14mm or 18mm thread.

Honda frequently use 10 & 12mm plugs for mopeds and lightweight models.

ian field wrote:
"N8N" wrote in message
oups.com...

mm wrote:
On Fri, 17 Nov 2006 08:02:47 -0600, "HeyBub"
wrote:

mm wrote:
It seems to me that all the screws and bolts on my Japanese motorcycle
are metric, except the sparkplugs.

AFAICT, neither the threads nor the socket required for the sparkplugs
used in my Honda are metric. Is that so, and how did it happen?


Huh? I though ALL sparkplugs were metric - a residual from the days
(~1900)

Well maybe the threads *are* all metric. I wanted to get a nut that
would go on a sparkplug, to make a spark tester, and none of the
English nuts fit. OTOH, I tried all the metric nuts and none of them
fit either. OT3H, they didn't have nuts in all possible metric sizes.
I think HD skipped from 12mm straight to 15mm, so maybe 14 would fit.

I believe almost all sparkplugs are either 14mm or 18mm thread.

Honda frequently use 10 & 12mm plugs for mopeds and lightweight models.

OK, how about "almost all *automotive* sparkplugs." I wasn't thinking
of small equipment applications and don't really know much about them
for that matter. IME the VAST majority of spark plugs are a standard
14mm thread although now you're going to ask me what the pitch is and I
don't know

nate

"N8N" wrote in message
oups.com...

ian field wrote:
"N8N" wrote in message
oups.com...

mm wrote:
On Fri, 17 Nov 2006 08:02:47 -0600, "HeyBub"
wrote:

mm wrote:
It seems to me that all the screws and bolts on my Japanese
motorcycle
are metric, except the sparkplugs.

AFAICT, neither the threads nor the socket required for the
sparkplugs
used in my Honda are metric. Is that so, and how did it happen?


Huh? I though ALL sparkplugs were metric - a residual from the days
(~1900)

Well maybe the threads *are* all metric. I wanted to get a nut that
would go on a sparkplug, to make a spark tester, and none of the
English nuts fit. OTOH, I tried all the metric nuts and none of them
fit either. OT3H, they didn't have nuts in all possible metric sizes.
I think HD skipped from 12mm straight to 15mm, so maybe 14 would fit.

I believe almost all sparkplugs are either 14mm or 18mm thread.

Honda frequently use 10 & 12mm plugs for mopeds and lightweight models.

OK, how about "almost all *automotive* sparkplugs." I wasn't thinking
of small equipment applications and don't really know much about them
for that matter. IME the VAST majority of spark plugs are a standard
14mm thread although now you're going to ask me what the pitch is and I
don't know

nate


Somewhere I have a really small spark plug that I drilled the HT stub so it
could be used as a key fob ornament, not sure what size it is but its really
tiny - its for a Honda portable generator.

mm wrote:

On Fri, 17 Nov 2006 08:02:47 -0600, "HeyBub"
wrote:


mm wrote:

It seems to me that all the screws and bolts on my Japanese motorcycle
are metric, except the sparkplugs.

AFAICT, neither the threads nor the socket required for the sparkplugs
used in my Honda are metric. Is that so, and how did it happen?


Huh? I though ALL sparkplugs were metric - a residual from the days (~1900)


Well maybe the threads *are* all metric. I wanted to get a nut that
would go on a sparkplug, to make a spark tester, and none of the
English nuts fit. OTOH, I tried all the metric nuts and none of them
fit either. OT3H, they didn't have nuts in all possible metric sizes.
I think HD skipped from 12mm straight to 15mm, so maybe 14 would fit.


when the ONLY sparkplugs a U.S. engine maker could get came from Europe.


But even if the threads are metric, don't spark plug sockets come in
13/16 for the big ones, and other English sizes for the smaller ones?

Somewhere I have a set of metric sockets complete with extensions and
spark plug socket, and I've been looking for them ever since I got my
motorcycle. CAn't find them, so I don't know how the spark plug
socket is labeled. (I've been using a bunch of metric sockets
gathered from junk boxes along the way.)


Are you saying we are slowly converting Asia to the Imperial System?


Yes, that's why GWBush is in Viet Nam. He's promoting the inch, the
foot, the pound, and most of all, the caliber.



If you are inclined to email me
for some reason, remove NOPSAM :-)

The two most commonly encountered spark plug thread sizes a

M14 x 1.25

and

M18 x1.5

Someone with a lathe having metric screw thread capability could make
you a nut pretty easily.

Or maybe you could find a junk cylinder head and bandsaw out the plug
hole area?

*********** Trivia follows:

Some early US spark plugs used tapered pipe threads like this one I've
had kicking around for years:

http://home.comcast.net/~jwisnia18/temp/plug.jpg

It disassembled for cleaning and had dual outer electrodes and a knurled
nut for connecting the high voltage lead. A copper gasket sealed the
ceramic to the lower body.

Mine is in pretty rough shape, the insulator was cracked when I got it
and I epoxied it in place for show.

It is marked "Champion" on one side and "Maytag" on the other, so I
imagine it was used in the engine of one of those gas powered clothes
washing machines which were popular before rural electrification happened.

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

ian field wrote:

Somewhere I have a really small spark plug that I drilled the HT stub
so it could be used as a key fob ornament, not sure what size it is
but its really tiny - its for a Honda portable generator.

They make even smaller ones, tiny really, for model airplanes.

On Fri, 17 Nov 2006 17:36:48 GMT, "Ralph Mowery"
wrote:


"mm" wrote in message
news
It seems to me that all the screws and bolts on my Japanese motorcycle
are metric, except the sparkplugs.

AFAICT, neither the threads nor the socket required for the sparkplugs
used in my Honda are metric. Is that so, and how did it happen?



I don't know about the newer cars, but about 20 years ago when I was going
to change the plugs in my first Datsun I stopped in the local Advance Or
Autozone store to get some plugs and a socket. I had a good collection of
American tools but nothing metric at the time. Told the guy in the store I
needed a socket for the plugs and thought it would be metric. He did not
know. We took some metric wrenches and matched them to the plug. They did
not fit,but when I put one inthe American wrenches, they did. Turned out I
had the plug socket for them all the time. Talked with a mechanic later
and he told me at that time all the plugs he changed were the American type.
I don't remember about the threads.

I think now I remember that even American plugs have metric threads,
like others have said. (It's just that HD didn't have 14mm nuts)

But we agree that they take English spark plug sockets, at least in
the US. Don't know about Japan.



If you are inclined to email me
for some reason, remove NOPSAM :-)

"mm" wrote in message
news
On Fri, 17 Nov 2006 08:02:47 -0600, "HeyBub"
wrote:

mm wrote:
It seems to me that all the screws and bolts on my Japanese motorcycle
are metric, except the sparkplugs.

AFAICT, neither the threads nor the socket required for the sparkplugs
used in my Honda are metric. Is that so, and how did it happen?


Huh? I though ALL sparkplugs were metric - a residual from the days
(~1900)

Well maybe the threads *are* all metric. I wanted to get a nut that
would go on a sparkplug, to make a spark tester, and none of the
English nuts fit. OTOH, I tried all the metric nuts and none of them
fit either. OT3H, they didn't have nuts in all possible metric sizes.
I think HD skipped from 12mm straight to 15mm, so maybe 14 would fit.

when the ONLY sparkplugs a U.S. engine maker could get came from Europe.

But even if the threads are metric, don't spark plug sockets come in
13/16 for the big ones, and other English sizes for the smaller ones?

Somewhere I have a set of metric sockets complete with extensions and
spark plug socket, and I've been looking for them ever since I got my
motorcycle. CAn't find them, so I don't know how the spark plug
socket is labeled. (I've been using a bunch of metric sockets
gathered from junk boxes along the way.)

Are you saying we are slowly converting Asia to the Imperial System?

Yes, that's why GWBush is in Viet Nam. He's promoting the inch, the
foot, the pound, and most of all, the caliber.



If you are inclined to email me
for some reason, remove NOPSAM :-)

If you need something to screw the sparkplug into, get an "anti-fouler" at
your auto parts store. It is an extension with a fairly small hole to move
the plug out of the combustion chamber.

Don Young

mm wrote:
It seems to me that all the screws and bolts on my Japanese motorcycle
are metric, except the sparkplugs.

AFAICT, neither the threads nor the socket required for the sparkplugs
used in my Honda are metric. Is that so, and how did it happen?

If you are inclined to email me
for some reason, remove NOPSAM :-)

Why not just get a "regular" spark plug and screw it into a "regular"
nut? It's just for testing spark right? Or is this tester to test the
plug itself?

On 18 Nov 2006 04:33:03 -0800, "Bike Guy Joe"
wrote:


mm wrote:
It seems to me that all the screws and bolts on my Japanese motorcycle
are metric, except the sparkplugs.

AFAICT, neither the threads nor the socket required for the sparkplugs
used in my Honda are metric. Is that so, and how did it happen?

If you are inclined to email me
for some reason, remove NOPSAM :-)

Why not just get a "regular" spark plug and screw it into a "regular"
nut?

Actually, I wasnt' using the plug from the motorcycle. I leave them
alone. I had a plug from an American car.

It's just for testing spark right?

Yes, I have some sort of tester that cost a dollar or two on sale at
Harbor Freight, but it didn't work here because it anticipates a splug
with the rounded nut on the end, and these plugs just have the screw.

And I thought of soldering an alligator clip to this spare plug, but
that would be hard because the plug is like a heat sink, and bolting
on a wire and having the alligator clip at the end of a short wire
seemed more versatile.

Or is this tester to test the
plug itself?

No.

The good news is that after disassembling my dual coil/condensor
package for the Honda CB450, and reassembling, now my right coil also
has spark, if anything, better than the left side.

This is especially good since of the coils I bought via Ebay, only the
right side seems to work.

So I found the 3/4" very narrow crack in my coil, probably caused by
my leaving the ignition on for 2 and half hours, and I filled it as
best I could with black GE silicone, and after that dried, I wrapped
it several times with silicon tape. That's the stuff -- hard to find
--one stretches and it grabs when you let go, and after a few days
turns to one glob of rubber. The best tape I've ever seen. So I
think, not sure, my coils will be all right for a couple years or
more, and if not I'll buy replacements then.


Thanks to you and everyone who enlightened me about spark plug sizes.

If you are inclined to email me
for some reason, remove NOPSAM :-)

On Fri, 17 Nov 2006 21:10:39 -0600, "Don Young"
wrote:


If you need something to screw the sparkplug into, get an "anti-fouler" at
your auto parts store. It is an extension with a fairly small hole to move
the plug out of the combustion chamber.

Will I still be able to see the gap, to know if it is sparking?

If so, that sounds good. Thanks.

Don Young

"HeyBub" wrote in message
...
ian field wrote:

Somewhere I have a really small spark plug that I drilled the HT stub
so it could be used as a key fob ornament, not sure what size it is
but its really tiny - its for a Honda portable generator.

They make even smaller ones, tiny really, for model airplanes.


The only ones I've seen myself are glowplugs which have a tiny coil of wire
up the end which can be heated with a LV battery for starting, after which
the combustion itself keeps it hot.

I suppose the more interesting question is in Japan, if the spark plugs
are the same, are the sockets the same. Do they have the same standard
size rachets or are the rachets themselves metric?


mm wrote:
It seems to me that all the screws and bolts on my Japanese motorcycle
are metric, except the sparkplugs.

AFAICT, neither the threads nor the socket required for the sparkplugs
used in my Honda are metric. Is that so, and how did it happen?

If you are inclined to email me
for some reason, remove NOPSAM :-)

"mm" wrote in message
...
On Fri, 17 Nov 2006 21:10:39 -0600, "Don Young"
wrote:


If you need something to screw the sparkplug into, get an "anti-fouler" at
your auto parts store. It is an extension with a fairly small hole to move
the plug out of the combustion chamber.

Will I still be able to see the gap, to know if it is sparking?

If so, that sounds good. Thanks.

Don Young


You may have to drill the hole larger or cut the male threaded end off. Take
a look at one and you can judge.

Actually, you can get a big alligator clip and wire and/or solder it to the
spark plug to do what you want better. You can even connect two clips
together, hold the plug in one, and clip the other to the engine.

Don Young

ian field wrote:
"HeyBub" wrote in message
...
ian field wrote:

Somewhere I have a really small spark plug that I drilled the HT stub
so it could be used as a key fob ornament, not sure what size it is
but its really tiny - its for a Honda portable generator.

They make even smaller ones, tiny really, for model airplanes.


The only ones I've seen myself are glowplugs which have a tiny coil of wire
up the end which can be heated with a LV battery for starting, after which
the combustion itself keeps it hot.

I had an original spark plug for old ignition engines (model airplane)
sold it on e-bay for 7-8 dollars.

The glow plugs you are talking about are actually kept glowing by the
catalytic reaction between the platinum, the alcohol in the fuel and
combustion chamber pressures, not the heat of the ignition cycle
itself.
O.K. I'll remove my nerd hat now.

Pat wrote:
I suppose the more interesting question is in Japan, if the spark plugs
are the same, are the sockets the same. Do they have the same standard
size rachets or are the rachets themselves metric?


mm wrote:
It seems to me that all the screws and bolts on my Japanese motorcycle
are metric, except the sparkplugs.

AFAICT, neither the threads nor the socket required for the sparkplugs
used in my Honda are metric. Is that so, and how did it happen?

If you are inclined to email me
for some reason, remove NOPSAM :-)



Different thread size plugs can be found with varying size outside hex.
I have seen three different sizes for the "regular" motorcycle thread
size 12mm plugs. The usual 21mm(20.6), 19mm and 16mm.

J.

Ps. If you look up:
http://www.ngksparkplugs.com/techinf...tnumberkey.pdf
You will find all there is to know about NGK's...