[bpe]

The seats are fine. Those open areas are there by design. They lead to a pathway for any water that gets into the spark plug wells to drain.

Move forward with the valve adjustment and crank that baby up.

 

[bpe]

Also be advised:
You have a first generation bike with a flywheel that is notorious for falling apart. Here is some info on how to take a more stable second generation flywheel and modify it to work on your first generation bike. >How to modify a 2nd Gen flywheel for a 1st gen bike (by FOG)