If this is a freshly reconditioned motor not yet free'd up with tight tolerances, an old starter motor and a small battery then its going to struggle.

And more to the point - the starter will be drawing so much current that the spark will also be diminished giving a double whammy on start up. It probably needs a good couple of hundred KM drive to get it spinning freely. Not a thrash - just a good drive.

There are a few threads on here about fitting more modern starters with less current draw and better torgue.

Mike

try scratch the paint off under the earth thats what my problem was