This is what they reckon on the Derv Starter causes the problems, but I got my new one from eurocar parts £86 odd with the discounts.
http://www.ebay.co.uk/itm/MG-ZR-ZS-2...-/251286741325
The difference in spinning it over is immense, I always thought the higher compression caused the slow turn over. This new one spins it up and its firing straight away.
Before it always took a couple of turns of the key to fire it.