You saw right through me. I guess I'm not as slick as I thought. thistle that is cleanest 10-10 I've ever seen. Usually you see them beat up pretty good. Nice saw!
It was the left hand brake/starter cover bolt. Threads on the bolt had some wear. So I replaced it with another & blue goo.
Late 60's - very early 70's popular workhorse.4.9 cube/80.5cc.A strong running one owner saw with very good compression ,very clean compared to how they usually are of this vintage.
Not really the whole saw. But shows why you might get a saw ported. Not a before and after of the same saw, but basically the same saw.