Warning sound

[Jdog]

I finaly got my boat in the water today and took her for a test drive and she hauled a$$, got on plane real quick and motor ran great, but the entire time the damn warning sound where the key goes was going off, I noticed when I trimed the motor up it would go off for a few seconds then come back on, I checked and the motor was pissing a good stream from the water pump.
Could it be the fact I was using a old plastic gas tank, and maybe the pressure wasn't good enough?

sorry for the noob questions.

One more thing the throttle linkage is terrible, almost all the way foreward and barely any increse in gas, then it's stiff and you have about one inch and that is where if u push hard it's a major increse.
All the way back and had no throttle for reverse, but she shifted in gear just no throttle.