Hard to start 725, changed everything? Any ideas

[Scrubcadet10]

I can definitely see the block moving

 

[ILENGINE]

I think what you are seeing is the flywheel screen is off center.look at :19. I looked at the block while it was running and don't really see the block shaking.
My $.02.

I saw the fan moving around but can also see the entire engine shaking on start up and when it dies. The engine in most cases doesn't shake while running but will make a clunking sound on start up and shutdown, and will see the entire engine move