How do I check if the engine will turn over?

It's an XS400 SOHC 1980. A US import. It ran, although not well, before I took it apart, which I put down to carb and/or electrical issues. The loom (harness) was a total disaster. Anyway, it's starting to come back together and the engine's in the frame but I want to check that the engine will turn over as it hasn't run for 2 years (yes, I know, pathetic progress). It's been kept in a dry garage, with plugs in and exhaust outlets blocked. The head came off and rings, valves etc were checked by someone who knows more than me, which isn't difficult. It was proclaimed to be in good nick.
At the moment the chain and gear lever aren't fitted, neither is the exhaust, but the kickstart is, so I tried turning it using the kickstart.
Plugs out. Kickstart vertical. As I moved the kicker down I could feel movement in the cylinders. The kickstart got to the bottom of it's swing and that was it. No way will it move any further, I can almost stand on it (it will go back to vertical without problem).
I can't tell if it's in gear or neutral because the gear lever isn't fitted. How much difference will that make?
Someone has suggested I fit the chain and turn it using the rear wheel. Good idea?
What's my next step?

Engine teardown to find out what somebody did wrong.

Should be able to take the timing cover off and turn it with a wrench.

Try turning the sprocket on the motor if in gear it should not turn. If in neutral it should spin.

The leverage is backwards if turning sprocket, making the effort too high.

spectra said:

Should be able to take the timing cover off and turn it with a wrench.

Try turning the sprocket on the motor if in gear it should not turn. If in neutral it should spin.

Click to expand...

Right, thanks for the replies. A few more questions.
I checked on Youtube and the general consensus seems to be to test if the engine will turn over remove the alternator cover on the left and turn the crankshaft with a socket/spanner/wrench on the end (anticlockwise). More than one person reckoned the 'timing cover off' (ie. using the camshaft) method could lead to damage if the engine is seized and too much force is used. Opinions please?

If I end up removing the alternator cover and providing the bike is upright, only a small amount of oil will come out. Is that right? Will I need to replace the alternator cover gasket or can it be reused (I think I know the answer but I'm asking anyway)?

The bit about 'turning the sprocket'. I assume this means get the rear wheel off the ground and rotate it forwards. Spins = in neutral. Won't spin = in gear.
I don't understand what amc49 means by 'leverage is backwards..making the effort too high'. If you're reading this amc49 I need a translation for idiots. Thanks.

You have a transmission there that uses gearing to create mechanical advantage (engine moves bike much easier), when you turn backwards through using the sprocket the advantage flips backwards to work against you. You can turn crankshaft easily to move the rear sprocket in even high gear, try to turn sprocket to move crank though and it is MUCH harder, you are geared backwards like that. Silly way to do it anyway.

You need to turn alt rotor counterclockwise like said and do NOT force it. Do not turn engine backward either, that can mess up cam chain works.

If the kickstart gear assembly not installed right and you happened to turn engine the wrong way the gear can strike on the side to lock up when you run out of spline. Trans can be in two gears at once too to lock if not installed right. Besides the normal engine lockups that can happen.