Rough running 9.9

[big country]

Just bought a sailboat with a 9.9 4-stroke, year 2000. The seller said he always used starting fluid to start it since he only cranked it every 2 or 3 months. I did'nt like that concept and can can crank it by holdimg my hand over the breather intake. It does run rough until it warms completly but is ok after reaching operating temp. I'm not sure what yamaha uses electronicly or otherwise for cold stsrts but if it had a manual choke there would be no problems. I have been thru the carb and confirmed all passages and ports are open, anyone have thougts on this?

[boats.net]

It is better to soak those carb in carb cleaner and use compressed air to clean, the jets and passages are so small and hard to clean. Make sure float height is set right.