turn over problem, is it the battery?

[CaliMorris]

when I try to turn over the engine, it turns fine for most of a rotation, and then slows to a crawl when the pistons start to compress, stops, and then continues once it passes that one "tough" part; a sound that reminds me of the little engine that could. It is almost like I am using a battery that is almost dead, or the starter is extremely weak. The battery is out of a v6 Chevy Malibu, and it is well charged, so I don't think that it is the problem. If it is possible that a switched/missing/disconnected wire could be the reason, then it probably is (I'm a novice at Morris wiring). it looks like everything is installed correctly though. I was really hoping to pull the cable and have a nice long healthy turning-over sound. Anybody have any ideas?

[MarkyB]

If the timing is too far advanced the engine will kick back against the starter, could it be that?
How well does it spin over with the plugs out?
A bent starter shaft will give similar symptoms

[bmcecosse]

Check for an earth strap between gearbox and crossmember. Try a jump lead between engine and battery earth for a quick check. If you are sure the battery is good - the starter may be in need of a clean/new brushes.