RE>Platinum Plugs

[Jim Cook]

-Arthur Okin ? writes:
-THE ONLY ONES THAT SEEM KIND OF INTERESTING ARE THE NEW BOSCH PLATINUM
-FINE WIRE TYPE BUT I KNOW SOMEONE WHO USED A SET BUT HAD CARBON
-FOWLING PROBLEMS ON AN OVERLY RICH ENGINE  ALSO A ENGINEER FRIEND
-OF MINE SUGGESTS REPLACING INSTED OF CLEANING BECAUSE OF THE 
-POSSIBILITY OF INSULATOR CRACKING

>Jens writes:
>There was no difference between the new and the old plugs. 
>This was exactly what the Bosch guy who sold me the spark plugs had
>told me (I did not believe it). From what he said, the Platinums last
>VERY long, esp. those zero-types with the special electrodes. He said
>the plugs are mostly used in racing engines and was surprised to find 
>them in a samll, very common car.

I have not had a dirt bike in about 8 years. But at that time the motocross
bikes came with platinum plugs. These had the very thin electode that has
been discussed. I was suprised to hear someone say that they had bad luck
with them fouling more than standard plugs. As I understand it, they were
used in dirt bikes because they resist oil and carbon fouling (two stroke).
One of the reasons for this is supposed to be that there is less parallel
surface between electrodes for deposits to accumulate or get lodged in. A
second reason may also be that the harder electrode tends to resist wear
keep a sharp edge for the spark to jump from. This may be more evident in 
a comparison on aging plugs.

Jim Cook