RE: Hirtenberger .61 with a sliding piston carburetor
Ihave taken to marking them with a scribe but most people open the package and install the plug then dont remove it until it burns out anyway.
And the color on the plug indicates its heat range. Red Green and Blue, hot ,med and cold.
We have discussed the web page and Iwish Icould take charge of it and make it more clear but he is having it professionally run and it costs money to make changes. Ihave a few too many projects now with my own web page to administer.