if any one can help me on this one

my rst starts first time its a bit lumpy to start with but thats probably the cam shaft piper285t2 if i go for a long run like southend or somewhere and i want to stop i cant leave it off more than 10 minutes if i do its hard to get started again
ive just had the fueling set up and the timing done when i try starting its like its just turning over and over ive got a new starter motor and heat shield because someone said the heat frys the starter and i have a new battery and alternator so i wont run flat

it just takes ages to start up after its warm has any one got any ideas cos im lost

thanks dave