9.9 running too rich and not running

[roguewave1]

I have a 1990 - 9.9 hp SD. It is dumping gas into the water, hard to start and will not come up to full RPM unless I remove the fuel line.

I have replaced the needle float valve assembly. Set the float to insure that the float is horizontal to base of carb when needle is seated.

What is the initial setting for the air mixing screw from a full clockwise position?

I wanted to try new high and low speed jets, but there are two different jets for each. How do I know which to purchase?

[boats.net]

Could be bad float or float valve, bad fuel pump diaphram, low compression or loss of fire to spark plug.
Setting is 1 1/4 turns.

[robert graham]

Sounds a lot like a bad fuel pump...Easy to check, easy to replace...Good Luck!

[roguewave1]

Thanks

Thank you Robert Graham. I rebuilt the fuel pump and the engine runs great.

[thlamers]

Runing Rich 9.9

I have owned a 1986 FT9.9EXJ since new and have about 5,000 miles on it. One of its problems was sticking carb floats. We first noticed gas in the oil during routine oil changes.

Upon opening the carb it was evident from scuff marks on the metal float chamber that the float was contacting the chamber wall and sticking open allowing the motor to flood.

Replaced the float but it in time expanded slightly so just sanded off plastic float material to assure clearance. No further difficulty in 15 years.