Electric start. 1981 750 Ltd

Hello.
The problem is when I try to start this 750 Ltd, it try's to turn over and then goes into a loud clanking noise.
I have checked out the starter motor, seems ok.
I then dropped the oil, took the cover off, checked the sprockets and chain from the starter to the clutch.
Now when I start it on the starter, I see the sprockets and chain turning, but then the clutch stops turning, and the clanking starts.
When it does start it runs well, but I am getting too old to kick it. I took the bike in exchange for a months tent from an ex tenent.
It does some times start well on kick, if I have the energy.
It seems to me that
1.
There may not be enough power to turn over the bendex when the piston goes into compression. I hooked the bike up to a car battery, it didn't make any difference.

2. The clutch needs adjusting. How?
I tried the center nut both ways in case it is a left hand thread. i could not get it off.
I also noticed that on the the metal shroud just before the large sprocket, there are 3 indentations as if something has tried to come from the inside of what I am guessing is the clutch housing or the (magneto housing) ?
I don't have a book.
Any suggestions?
Thanks