One thing that wears without real notice is the starter. Of course on a Honda that has been ridden much. So the CB900f didn't start that good anymore. You do get used to that, but it was time to give it a look. Not much work, but it was really needed as you will see...

How do you notice your starter needs work? It will not go round that quick anymore, and also your battery seems to lack of power.

Starting with the tools. That's all!
When you've got the starter you begin with loosening the three long screws.
After loosening the screws you can pull the tap off. It might be stuck a little, due to filthy grease and a rubber ring.

In the endcaps you will find the dirt. I rinsed it off with an (old) toothbrush and some white spirit (wasbenzine).

So this is the pile of crap that came out of the starter... It suprised me too! My guess is that it will run smoother.
Clean and ready to install again. Apply some grease on the bearing, put it together and mount it on the bike.