Topic: Expensive sounding noise in gearbox?

[kingrabbit]

This one can be read in connection to my earlier post from a few hours ago "HauTnted Starter..."

Basically the bike (a 74 CB550K ) which has previously been reliable has developed a loud mechanical cracking sound as I try and start up.
Earlier today the starter would not disengage even after I hit the kill switch and pulled the key.

Anyway I recharged the batt and am trying to fire up again.
If I hit the starter the bike turns over and after a few seconds a loud mechanical snapping sound comes from the gearbox area.
When I kick it over it will generate the same noise every 4 or 5 kicks.
What could it be and what is my next move to narrow this down?

[kingrabbit]

I should have asked earlier could adjusting the points gap and valves cause this somehow? I did that immediately before this problem started.
Could a dodgy oil pump cause this? I replaced the oil pump switch recently. It seemed to be working fine for the past 6 weeks or so since then.

[dave500]

if its making the noise even with the kicker that bypasses the starter clutch drive,it might be locked up though and turning as you kick?you might drop the pan first and have a look?see if theres any metal pieces?if you remove the starter motor the big gear you see inside should turn one way only and feel smooth,id have a look at that.

[kingrabbit]

Thanks good people!!