Topic: Spark plug: Old age or too hot?

[trueblue]

Dunno Dave, i'm not old enough to have fitted KLG plugs, but I have removed them from an old Morris Major, in 2006 it got it's plugs changed for the second time at 25,000 miles and was still owned by the same fella who bought it off the showroom floor when it was new.

[Terry in Australia]

KLG's were really good plugs Dave, and the thing I liked was that they were designed to be disassembled for cleaning. I want a set of Golden Lodge spark plugs, they were "the oil" back in the day.

http://www.ebay.com.au/itm/Alfa-Romeo-33-Sprint-Alfasud-Golden-Lodge-25HL-Spark-Plugs-Genuine-New-/300746152828?pt=AU_Car_Parts_Accessories&hash=item4605de1b7c

[dave500]

as a kid terry i would scrounge at the tip,i found one of those plugs you could dissemble,i forget the brand but the type was commonly called a "mica plug"due to its insulation or something,,i kept that plug for years and gave it to one of my teachers at trade school,he was into really antique bikes and it was the type of plug he could use,,he ran the bike on normal plugs but showed it with the period correct ones,he was happy about getting it,i still havent gotten that beer yet?i was 16 at the time though.

[PeWe]

Order spark plugs from far east? The very expensive site too?
You must have that closer in Germany, like eBay.de. If not, try Wemoto in England. They have some nice parts. Here the link, I have found your model for you.
http://www.wemoto.com/bikes/honda/cb_550_f_f1_f2/75-80/

I have ordered some  for my CB750, drive chain sprockets kit, handlebar and various parts incl. mirrors to a Kawasaki Z1-900 which have I used before when they are far better than the junk from Honda. I got a pair many years ago when I had broken the second Honda OEM junk in short time. Z1-900 mirrors worked well until one disapperad (stolen). Less vibrations in higher speed and easier to adjust. Black instead of chrome though.

[Terry in Australia]

as a kid terry i would scrounge at the tip,i found one of those plugs you could dissemble,i forget the brand but the type was commonly called a "mica plug"due to its insulation or something,,i kept that plug for years and gave it to one of my teachers at trade school,he was into really antique bikes and it was the type of plug he could use,,he ran the bike on normal plugs but showed it with the period correct ones,he was happy about getting it,i still havent gotten that beer yet?i was 16 at the time though.

Yeah mate, my cousin is a vintage car nut, (he's got several cars that are getting close to 100 years old, plus a nice 1944 Indian Chief) and I needed a 3/4" dia (from memory) spark plug for the KLG spark plug cleaner he gave me, so he took me through his vintage spark plug "collection", he's got boxes and boxes of NOS KLG and Lodge plugs, and others that I've forgotten. I love wandering around his shed, it's like a time machine! Cheers, Terry.

[Fritz]

Order spark plugs from far east? The very expensive site too?
You must have that closer in Germany

Well, Yamiya had some parts (instruments chrome bowls) that I did not find at eBay at that time. Since one of my customers is a Japanese company*, I asked one of their guys to bring the parts with him on his next business trip to Hamburg. *no, it's not Honda, but one of their competitors, unfortuneately I deal with their musical, not their motor section Seeing the "non-resitor" spark plugs on Yamiya's site, I ordered them along with the other parts. The Yen->Euro exchange rate was very attractive, you know...

[Fritz]

I AM certain that the electrode wasn't melted by combustion temps., or eroded by spark energy (which would occur on two plugs rather than just one).

If the owner is insistent that the plug damage was from over-temp, I'd check the intake for air leaks, I suppose.

Thanks LLoyd.
No, I agree with you and do not think that the failure was caused by overheating. Though your comment reminds of a small 'sloppiness': Two months ago, I changed the O-rings of the intake manifolds. Unfortunately I only had three of them new at hands, so one of them has been left unchanged. I don't know if it's the one of cylinder #1. But I'm sure that I checked that it was still wide and soft enough to seal sufficiently. Maybe I should measure exhaust header temperatures...

After buying a new rotary tool, I'll try to cut the plug. I don't know if the examination of the failure of a $3 spark plug is interesting for the rest of the forum members, but I'll post pictures anyway.

Cheers
Carsten
 

[Teatimetim]

yes I 'de say just a deffect in the plug, that showed itself under heavy load.

[Terry in Australia]

I AM certain that the electrode wasn't melted by combustion temps., or eroded by spark energy (which would occur on two plugs rather than just one).

If the owner is insistent that the plug damage was from over-temp, I'd check the intake for air leaks, I suppose.

Thanks LLoyd.
No, I agree with you and do not think that the failure was caused by overheating. Though your comment reminds of a small 'sloppiness': Two months ago, I changed the O-rings of the intake manifolds. Unfortunately I only had three of them new at hands, so one of them has been left unchanged. I don't know if it's the one of cylinder #1. But I'm sure that I checked that it was still wide and soft enough to seal sufficiently. Maybe I should measure exhaust header temperatures...

After buying a new rotary tool, I'll try to cut the plug. I don't know if the examination of the failure of a $3 spark plug is interesting for the rest of the forum members, but I'll post pictures anyway.

Cheers
Carsten
 

All the best with that mate, those plugs are very tough, especially the porcelaine section, but if you manage it, post the pics, I'm interested to see what's happened. Cheers, Terry.