Should the crankshaft rotate both ways?

[Kwackman]

Hi,
I'm rebuilding a Z400J3 engine (4 cylinder baby Z1).
This my first rebuild, so newbie errors are very likely.
So far, I've got the gearbox shafts etc in along with the crankshaft and have the crankcases bolted together.
No pistons or barrels or clutch basket as yet.
The starting motor is fitted, and I've just fitted the secondary shaft which has the starting motor clutch mechanism and primary chain teeth.
The crankshaft only seems to turn in one direction since fitting the secondary shaft.
I'm assuming this is OK, because of the starting motor clutch?
I'm rotating the crankshaft by hand, turning the alternator rotor, because it's easy to get a hold on.
I haven't tried too much pressure to make it rotate in the direction it doesn't want to go.
I'm just looking for assurance that I haven't messed up?

Amongst the many screw ups so far has been putting both bearings for the secondary shaft in the crank casings before spotting the shaft has to go in first, before the second bearing can be fitted....- that's the level of stupidity we're dealing with here!

[Julian_Boolean]

I don't know the 400J specifically, but every bike I've had the crank has turned both ways.
Is the cam chain jamming when you turn it backwards?

[Kwackman]

Thanks for the reply Julian.
No, the cam chain isn't jamming unfortunately.
The engine is upside down on a stand at the moment, the cam chain is moving freely.
I'll re-look at parts diagrams and the manual tomorrow and see if I've missed something.
Thanks again.

[z1bman]

remove the starter motor it should turn freely both ways then

[Kwackman]

Thanks for the reply z1bman.

Removing the starting motor has got me sorted, but not in the way you might have expected!
Initially, it didn't change anything, so I put it back.
But after removing the secondary shaft (I'm getting better at this now!) the idle gear still seemed solid.
Removed the starter motor again, and the idle gear spins fine.
So, after refitting the starting motor, and the secondary shaft, it all seems to work as expected now.
I suspect I somehow jammed the idle gear either with the starting motor, or the secondary shaft assembly.

So, thanks to you both for the replies, I'm glad I asked.
No doubt I'll be back soon with more "Doh" moments.