Pulled out my Merc 9.9 HP ob motor to start it in prep for a trip next week. I could initially get the motor to run, but only with the choke on and for very short periods of time. The engine would die afterwards. For the longest time I could not get it started. Pulled the plugs and could definitely smell gas on them, so the engine seemed to be getting some gas, but simply wouldn't start. I had to keep using the priming bulb to get fuel into the engine, so I pulled the fuel pump off and had a look. I found the black and white (clear actually) check valve assembly to be put in backwards (white, then black, as opposed to black, then white). This is a bit weird because I have never taken the pump apart and the motor ran fine all last year. Put it all back together again correctly and again couldn't start it. The bulb seemed to keep more pressure on the fuel system. Had someone slowly pump the bulb while I tried to start the engine and it finally did. Ran it for twenty minutes at idle (with cooling water), shut it down and started it again without issue. However, I noticed that there was a lot of air in the fuel line between the pump and carb. Motor was idling fine but should there be air in that fuel line and where would the source of air coming from?
