Mariner 9.9 hp won't stay running at idle

[Lasha malazonia]

Hi I have a 1997 mariner 9.9hp outboard.i was having trouble starting the motor after a fishing trip, so I tightened the idle screw and got it to stay running.it was running for about 15 mins when i loosened the fuel mixture screw on the carb with the intent to even out the higher idle speed. The motor shoot down after 5 mins, and now it won't stay running unless I put the throttle high and do not let it idle. It is very hard to start it now too because as soon as it starts and idles it shuts down. So I have to take the cover off and open the throttle with my hand and start it that way. I tried to re adjust the screw but I can not get it right. What is the best way to tune and adjust the idle screw and the fuel mixture screw, and have the engine running smooth. Please help and information would be greatly appreciated.

 

[MH Hawker]

The idle / mixture screw has little to nothing to do with high speed running, but it dose have ever thing to do with idling and starting back it out till it idles smooth, then you may have to make little adjustments for cold starts, it loves a rich mixture. To have nice easy starts it needs to be rich.