Bukh 20 over-revving out of control

Using a borrowed 41mm box spanner, I got the injectors out and all looked well. No dribble marks or other indications of an unusual spray pattern. I also re-checked the governor, which flicked well against the spring and returned to idle position. So with growing confidence, I fitted the pump, bled the system and lo-and-behold - the engine fired up and ran nicely - properly responding to the throttle control. YIPPEE! I test ran it for 20 mins and it was fine. I'll do so again later today, but it does seem like something blocked rather than broke - and I've unblocked it. Many thanks to you all for your expert help.
 
Thanks. My worry is that I don't actually know what caused my problem. I am wondering if I actually had a real runaway engine, or whether my engine whizzed up to its maximum speed for some reason.
I discovered that one of my injectors was loose, so that's now tight. I must say that the engine is now running quieter, with less vibration and spinning more freely than it ever has (in my limited time of owning it).
So all I can do is just use the boat and if I get a 'run' up to max speed, I just shut it off. I don't think there's anything else i can do. But thanks again.
 
Top