Appreciate some input on spark plug reading

Here are two plugs from an engine I’m tuning.

The plug with the shell on is where I started. Way fat.

The plug with the shell off is the last pull yesterday. It’s close but not there yet.

There is probably 8-10 hp left with carb changes but it’s still a bit fat. I could put fuel back in it, but it will lose power.


View attachment 1716241037View attachment 1716241038
The new plug looks rich towards the top end of RPM. Getting better... Can't see the ground strap to see where timing is at in these pics