Mariner 50 going out weak.

[al windybank]

First of all, thanks to everyone that helped me last time.<br /><br />I have an early 80s Mariner 4 cyl 50hp. I've just fitted a carb kit to one of the carbs to stop a leaking needle valve and she now runs alot better. However, periodically she goes out weak when running in gear at low revs and will not start again straight away. When I try to start her she just spins, not firing at all. However, if I give her full choke she fires for a second before dying. But she will then sometimes start immediately after (with a few pumps of the throttle).<br /><br />When she first goes in the water she starts at a touch with choke and throttle. When she is warm and running ok if you switch her off then on again she also starts at a touch. Why is she dying sometimes at low revs and then failing to restart?<br /><br />Ideas appreciated.