Combustion residue patterns

[2strohked]

So I’ve recently had my bike overtemping and the filling of my overflow. The rad cap is original so I ordered a new oem one. In the meantime I’ve pulled the head just to verify there wasn’t any gasket leak.
No leaks, but what I did notice, and I don’t think this is related to the overtemp issue (but I may be wrong?), is that the residue on the head is only about half way around. Piston tops are fully covered. I lapped the head down myself so I’m pretty sure it’s even. Squish is sitting about .093. Not running a gasket, just 1211.
I’m more curious about the pattern than thinking it may be an issue. Other than the recent overtemping, the bike runs excellent and starts on first kick everytime since rebuild 1k miles ago.

[kpke]

Looks OK to me but hopefully the experts will weigh in here.

I am really curious about running with no head gasket and only using 1211. Clearly you have some sort of coolant issue so will be waiting to see if changing the rad cap solves the problem. Or maybe it has something to do with no head gasket?

[2strohked]

While no leaks have been found at head (no)gasket, I’m not sure how it would cause an issue. The first 1k on the rebuild has been amazing, although I say that only from my non-professional ability to take things apart and rebuild them and only fine tune them from applying the multiple things I’ve read/watched.
I also think that even though my rad(original) seems to flow freely, I may replace it soon as well.
As for the patterns, I find it interesting to see in the first pic that it seems to ignite and the plug blocks the combustion on one side.
Appreciate your input Ken, I will be sure to update here.

[Smoker]

Was looking at your pics and started wondering if indexing the spark plugs would be a good idea.

I know how to index plugs, but not sure if it's different on 2-stroke engines.

Any opinions?

Would also be good to see a shot of the whole head to compare the position of the burn patterns.