Ron
Club Member
A friend of mine passes me his old motorcycle mags and I found the following to be interesting. It's from the MZ Owners' club mag, a good read. They seem an interesting bunch and get about a fair bit.
It starts with a reference to poor hot starting and the use of NGK plugs. The writer had used NGK's all his life and swore by them until they started playing up in his two big Panther M100's (600cc singles). The bikes would misfire and the plugs fail early. While hunting out a genuine, (there are fakes about) new, old stock NGK he found the Green Spark Plug Co website which offered an explanation for the premature failure of NGK plugs.
To comply with environmental regulations the porcelain part is no longer glazed because the glaze contained lead. The porcelain is now porous and cracks when coming into contact with cool inlet mixture. The hairline cracks are invisible and can occur throughout their length but the net result is electrical tracking, effectively rendering the plugs useless.
The writer then goes on to explain why the NGK's work in other vehicles. Most are fuel injected so amounts of fuel are accurately metered and less likely to be subject to carb tickling, accelerator pumps or heavy choke use causing a big slosh of fuel to wet the plug. I know my Pan/Shovel likes to be nearly flooded from cold. He went on to try Champion and Lodge plugs in the Panthers, neither of which failed.
Another mag had a owner with a old 250cc Triumph playing up, hard to start hot and cold. It was also burning oil which lead him to think about using a plug designed for an oil burning engine, an old style two stroke in fact. He changed to a Brisk plug from F2 Motorcycles who sell new motorcycles like that and a new plug fixed the starting.
I use Brisk plugs in both my bikes after seeing then mentioned on this site somewhere and on F2's site they do say that the plugs are made to suit older style engines and recover well from over rich mixture at start up. The Brisk site briskplugs.co.uk has an extensive fitting list.
So many things that used to work well have now changed to be suitable for modern use but less so for older machinery, we can't rely on a old product just because it always used to be good.
It starts with a reference to poor hot starting and the use of NGK plugs. The writer had used NGK's all his life and swore by them until they started playing up in his two big Panther M100's (600cc singles). The bikes would misfire and the plugs fail early. While hunting out a genuine, (there are fakes about) new, old stock NGK he found the Green Spark Plug Co website which offered an explanation for the premature failure of NGK plugs.
To comply with environmental regulations the porcelain part is no longer glazed because the glaze contained lead. The porcelain is now porous and cracks when coming into contact with cool inlet mixture. The hairline cracks are invisible and can occur throughout their length but the net result is electrical tracking, effectively rendering the plugs useless.
The writer then goes on to explain why the NGK's work in other vehicles. Most are fuel injected so amounts of fuel are accurately metered and less likely to be subject to carb tickling, accelerator pumps or heavy choke use causing a big slosh of fuel to wet the plug. I know my Pan/Shovel likes to be nearly flooded from cold. He went on to try Champion and Lodge plugs in the Panthers, neither of which failed.
Another mag had a owner with a old 250cc Triumph playing up, hard to start hot and cold. It was also burning oil which lead him to think about using a plug designed for an oil burning engine, an old style two stroke in fact. He changed to a Brisk plug from F2 Motorcycles who sell new motorcycles like that and a new plug fixed the starting.
I use Brisk plugs in both my bikes after seeing then mentioned on this site somewhere and on F2's site they do say that the plugs are made to suit older style engines and recover well from over rich mixture at start up. The Brisk site briskplugs.co.uk has an extensive fitting list.
So many things that used to work well have now changed to be suitable for modern use but less so for older machinery, we can't rely on a old product just because it always used to be good.
