I have a 1985 kawasaki 454 LTD. Been having a temperature issue with the bike getting hotter than it should.

Anyways, I've flushed the system and it flushed clean, removed the thermostat, and still have the tempreature issue. I figured I would drain the system to put a new thermostat in, and while I'm there I thought I would inspect the water pump. It looks easy enough to remove. Looks like 4 bolts on the outside and the pump should slide out. It does come out about 1/8 of an inch, but does not want to come out any further.

Is there more to it than what I'm seeing?