I am having a problem getting my fuel bulb tight. The only way I can do is to take off the connector at the motor and pump gas back into the tank and then quickly put the connector back on. The bulb will get tight then but only for one outing. The motor is a 2005 9.9 4 stroke yamaha. The fuel tank is a permanent plastic 12 gallon.  I tried a new universal fuel line with a new connector and I cant even get the new one to get tight at all. The other thing is that the motor will still start even if the bulb is not tight but not near as fast if the bulb is tight. Any ideas on what I need to to do?

Now that is a tough one. IF you have a buddy with small out board that you can try might give you some idea as to what may be causing you your dilima. If the bulb will get firm with your buddys motor then the problem is in the connector on your mother but if the bulb has the same problem with both motors then the problem is with the bulb/fuel line. Just because a part is new does not mean that is is not defected

Good Luck

YOu may want to check the fuel pump diaphragm.  It could need replacing.

I had the same problem with my big motor. Finally took it to the shop. Replacing the Yamaha bulb with an Evinrude equivalent did the trick.  Mechanic said something about the 'Rude's bulb being stronger than the Yammie.  It works great now, so I don't question it.

I used to have problems all the time with the connector end. I was replacing new connectors on my Yamaha every couple seasons.  Then a Yammie mechanic told me the problem was on the motor side, the connector there was ever so slightly misaligned causing the connectors to wear and never seat right.  He suggested to just take out the connector and run the fuel line straight to the fuel filter.  I did and have never had a problem since.