In the process of stripping my engine down for cleaning and general maintenance.
Motor is unknown to me and the service history is unclear even if I have the bills
of a $4000 rebuild about 20k miles ago.

https://www.dropbox.com/s/ihvhpljgeeckno0/F...9%2058.jpg?dl=0

I have removed all the slotted screws and the 3 13 mm headed ones but the cover wont split. I found this that could be a bolt broken by a PO even if the surface of the
metal looks way too clean for a broken bolt.

If I carefully wiggle a screwdriver between the housing halfes the whole left side (referenced from the picture) above is loose and also the bottom right, its the area
to the right the red circle that still resists the most.

Am I missing something obvious?

Solved with some heat and carefull wiggling around the dowel pin that I thought was a broken screw.

It's pinned. Try not yo pry it until you've knocked it apart a little.

The Cap'n

I had far more trouble splitting the fan than I did splitting the case the first time.

And yes its the pin somewhere near the middle (IIRC) that you have trouble prying on directly.

I have one at home already spit if you need pictures of the inside.