1999 200 Opti Priming Issue???

[JCJ]

Serial #0G886121 --- I'm having an issue with getting my primer ball to stay firm, and thus the engine to run right. I replaced the fuel line from the tank to bulb (3/8"), and from the bulb to diaphragm pump (5/16") along with installing a new bulb (Mercury OEM bulb). I also rebuilt the diaphragm pump (Mercury parts kit). I can get the bulb to sometimes get firm, but then it will go soft again after shutting down. What's weird is when I try to pump it back up (bulb soft again), a lot of times it feels like fuel is kind of bubbling through, or back feeding??? I can take the line off the diaphragm pump, and it's like it got a lot of air in it. Leaving the line off I can eventually get it to push fuel out the end of the line by pumping the primer ball again. It starts out spitting, but will finally start pushing a stream. However, when I hook it back up, I go through the same issue. Could it be something with my diaphragm pump causing this? I looked, and didn't see anything wrong with the rebuild??? Thanks.

[Savage]

Point the arrow on the side of the bulb towards the sky. The bulb is not supposed to stay hard while the motor is running.

[JCJ]

Thanks, and I'll look at this. What is the best way though with the bulb/hose laying in the splash well?

[Rip Bass]

If you don’t have enough extra hose to hold the bulb vertical, you can add a little hose. Losing prime and having air in the fuel makes me think you have a leak between the bulb and the tank.

[EuropeanAM]

Keep in mind that today's fuels vaporize at very low ambient temps. Bulb must be pumped firm before EVERY engine start (especially important in warmer temps).