I have an 1987 8HP Mariner outboard that runs great but it idles funny. It starts right up. I push the choke in after a few seconds and then it idles fine for about 1 minute, then it seems to run out of gas and dies. If I pump the bulb it's fine. If I leave the choke out it's fine. When running fast there is no problem. It will run for an hour fast but only idles for about one minute with the choke in. Any ideas you can pass on to me? Frednick1