Hi everyone so I took my 6hp 1974 fisherman out this morning and it ran great. I noticed when I first started it at the dock it would cough every now and then in the shift position. The coughing stopped for the rest of my trip and it was running excellent. When I got back home and threw it in my test tank to flush it out, it started coughing a lot more and sometimes shutting the motor off. Now sometimes it will be idling okay then start coughing for a little bit then go back to idling okay.