XJ650H Motor is locked up

I am having such a bad day.
I replaced the carbies with a correct set see my other post.
I tried to start the motor and it turned over fine but a bit slow, so I put the battery on charge for a few hours. When I tried to start it again nothing happened other than the relay clicking, the motor appears to be locked up.
With the bike in gear the back wheel will not turn at all, I pull in the clutch and the back wheel turns so that rules out the gearbox.
I removed the starter motor and the drive cog will only turn backwards.
The starter motor runs fine out of the bike
Tried to bump turn the motor by pushing it back and forward in second gear, but it is locked solid.
Is there something in the starter clutch assembly that can cause this.
Help and suggestions please.

 

One thing to try , pull the left hand crank cover , put a 19mm wrench on the crank bolt turn it counter clockwise. See if engine will turn if not then , try soaking the cylinders with a 50/50 mix of ATF and Acetone let it soak for a day and try again to turn engine over.

 

Took off the side cover and motor turns over fine PHEW. Tested starter motor again still works. so fitted it back on and BINGO it turns over fine. The starter must have a bad circuit in it somewhere but now I know. P.S. these bikes need a really good shove to bump startthem I guess.