Managed to snap two bolts today taking apart the engine mounts. Got the old exhaust out and the new one on. The original was 270mm long and 39mm wide, new one is 260mm long and 48mm wide. Apparently gives better top end.
Also opened up the exhaust ports some more (top one is from yesterday, middle is towards the end of today)
Did some polishing and cleaning up on the intake/ front half of crank case
Then started on the back half of the crank case. You can see the casting imperfections here -
Smoothed off the sharp edges -
Still needs to be polished -
I tried to keep the work done equal for all cylinders