These are the pictures I can take right now
This is what I see looking at the spark plugs. on Reply #4 on: June 14, 2020, 07:04:14 PM
Pictures 1,2,3:
The first 3 pictures show the spark plug is operating at too low of a temperature too keep the center electrode and porcelain burned off and clean. The steel shell that occupies the area that is about 2mm long below the last thread and the surface the ground strap is welded to, is also running too cold. This shell area should be scorched, blackened or be dry with soot or carbon when the combustion temperature is in the the range of a well tuned carburetor and riden aggressively. Some possible causes for this low steel shell and porcelain operating temperature could be due
to one or a combination of the following:1. Low shell temperature is usually an indication of low combustion temperature and or very brief periods of full throttle.
2. The circuit in the carburetor is very rich in the throttle positions where the engine spent most of it's time running.
3. Periods of wide open throttle are too short and or there is too much time elapsed between periods of wide open throttle.
4. We cannot evaluate the heat range at this point because the shell is running ice cold. A hotter heat range spark plug will raise the operating temperature of the porcelain to keep the porcelain a little cleaner for the current carburetor tune, and riding style that this spark plug experienced. A hotter heat range plug will not change the operating temperature of the shell area below the threads or the area where the ground strap is welded to the shell.
Picture 4 indicates the spark plug sealing washer was sitting on an uneven surface. One side of the sealing surface of the washer is flat while the other side is still round. I would remove the sealing washer from the threads and screw the plug into the head only finger tight and look at the sealing surface on the head and the plug base to determine if the threads and head sealing surface are 90 deg. to each other.
