Fuel pump psi

[pursuit2460]

I have a 93 johnson 225. Today I hooked up a tee with a pressure gauge. Primed the primer bulb pressure gauge went up to about 15 psi then started to drop is this normal. Next I start the engine and the fuel pressure fluxuates from 2-3 psi at 1000 rpms. The pressure drops to 2 psi then you feel the fuel pump pump and psi raises to 3 psi. I let the motor idle for 5 mintues and check the primer bulb and it got soft. Ive checked the posts but nothing like what im encountering. thanks

 

[ezeke]

Re: Fuel pump psi

Sounds about right. Pump just gets the fuel to the float bowl. Engine vacuum and the reeds take care of the rest.

 

[seahorse5]

Re: Fuel pump psi

Minimum fuel pressure on your motor is 3 psi.<br /><br />You will need to use a vacuum gauge and some clear line to check the boat's fuel system before condeming the pump. It is explained in the service manual.

 

[Silvertip]

Re: Fuel pump psi

Primer bulbs are not under pressure when the engine is running. Fuel is sucked through them. Depending on how the bulb is laying, it may only be slightly more than half full of fuel when the engine is running. If it ever gets sucked flat however, that points to a restriction between the bulb and the pickup in the tank.