Motor turns VERY slow

[COOTER]

I installed a new crank and cam gear, buttoned it all back up, set the timing and now the engine turns very slow. I'm talking really, really slow. Turns by hand pretty easily. Anything other than a low battery that would cause this. It was late in the evening so didn't get a chance to check voltage yet. Just wanna have a game plan before I get out to work on it again.