I've just done a full fiesta rs turbo conversion with ofab loom, I am having a starter motor issue, I just brought a recon starter which in the ad says its for both fiesta and escort 1,6 turbo, but when I turn the car over it seems that the starter is not engaging you can hear the cog just spinning, then if you carry on for around 10seconds it's starts grinding on the fly wheel? Is this a starter motor problem? Or not enough power going to starter?

 

Sounds like a dodgey starter.

 

Is the gearbox spacer fitted between engine and box? Is the ring gear on flywheel in good order?